iTopSpin
Current Posts => Collecting, Modding, Turning and Spin Science => Topic started by: johnm on May 29, 2010, 08:56:38 PM
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You may never look at a milk jug the same way again. ;)
I'd been thinking about using milk jugs as a source of cheap plastic for learning about injection molding and making some plastic tops which might be less likely to break on our hard surface play areas. After harvesting a large piece of aluminum from some scrapped equipment (aerospace engineering has really large experimental equipment), I designed a two part spintop and the molds to inject them based on the size of the aluminum stock. I had planned to do the machining myself but could not pass on the offer of one of the shop guys to make a piece here and there during slow times. About two or so weeks ago, the final components of the molds were completed. Since I haven't finalized the design of the injector and I couldn't stand letting the molds go unused, I tried casting with them in an oven by simply melting the plastic directly in the lower part of the mold and pressing the upper part into the melt and letting the assembly cool. Although there are some problems, it works well enough to make some very playable tops.
Here's a pic of the molds and some of the milk jug tops. The molds are open to show the assembly on the bottom with the additional mold-half stacked above with a formed part installed for demonstration. On the right is one spinning top assembled with tape and its string with milk jug lid button.
(http://farm5.static.flickr.com/4012/4650605117_b50083f87d.jpg)
One of the problems is the shrinkage of the plastic upon cooling. I knew it would shrink but had no idea about how to design that into the mold so I just designed it to my intended shape. For the cap in the mold on the right you can easily see the gap between the mold and plastic. Another problem is air that gets trapped when the bits of plastic melt. These air pockets can leave blemishes (hard to see in the picture) on the cooled surface and can leave major hidden voids which affect the balance. Because of voids and variable squeeze out the weight is not very consistent between tops but a cap and base are around 60 grams and a milk jug with the paper label cut out is also about 60 grams so 1 jug = 1 top. :)
The blow molded HDPE (high density polyethylene) of the milk jugs doesn't melt together really well but what works better is injection molded HDPE such as that found in milk crates and 5 gallon pails. These have the added advantage of coming in lots of different colors as demonstrated by some of the tops cast from 2 liter bottle crates, bread crates, pails, and pallets (basically anything with a recycle number 2).
(http://farm5.static.flickr.com/4027/4650605355_fb5140f3ca.jpg)
For a size comparison here from left to right are
1. turned HDPE from a melted pail, 2. Spintastics Trompo Grande, 3. Cast HDPE, 4. Duncan Ripcord, 5. Spintastics Gladiator, 6.Mexican 5 Estrellas Atomo
(http://farm5.static.flickr.com/4019/4651223854_dc29a44554.jpg)
Currently, the tops with the tips in the middle pic are the ones we've been beating around the halls and have had no casualties. Even Aaron the top-destroyer hasn't broken any while learning suns, so you know they've been launched and slammed into concrete walls, pipes, hard floors, and steel door jambs.
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That's pretty awesome! How are you melting all of that plastic?
Rob
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I am impressed. In the last pic, the shape reminds of a Gates.
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Wow! On to something new and exciting and awesome; wow.
I totally dig the solid red & solid blue ones...
I finally tried to turn a few tops over the past week, but still working it out...
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My kind of recycling!
I am speechless! Amazing work, John!
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SO COOL!!! I love the multi-color. I may start warehousing #2 plastic. I am a customer should some become available!
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Holy Lactating Spin-Tops!! ...I mean WOW!!! These are freakin awesome!!! Love the ingenuity, colors, shapes, the fact that the two halves tape together evenly (unlike snap together tops).....and I love the matching milk cap button :) Reminds me of when Pedro's came out with tire levers and water bottle cages made from recycled milk jugs. Mucho Props! I'm your biggest fan :)
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Wow, John, those are seriously cool! I love the shape. I'm with Chris, I've got a check here with your name on it if/when you're ready to part with a few.
Have Fun,
Tom
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How are you melting all of that plastic?
For the molds, the plastic is all cut up with a tin snip (to avoid all the little fuzzies generated by band sawing) to bits about 1cm x 1cm and heated directly in the mold in an oven at about 180 Celsius. When the initial charge of plastic melts together and creates some space, additional bits are added to ensure the form is overfilled.
For the larger turned tops, I have an old copper beaker which I wipe with some silicon grease as a release agent and fill with band sawed chunks (the fuzzies don't get in the way here) and refill as the stuff melts down. I've only made two 'blocks' of the stuff and both times there was a single major void inside the piece. The first time the block was unusable so is will be remelted. The second one became the pictured top which still has a small portion of the void inside which contributes to some wobble.
I am a customer should some become available!
I've got a check here with your name on it if/when you're ready to part with a few.
Thanks for the interest. Unfortunately, I don't have any intentions of selling these tops. I play/make/think about tops strictly as a hobby for fun. I know that if I start selling tops (plastic or wood), the fun will be replaced by stress and ruin the experience for me. Besides that, my casting process isn't really reliable and the time it takes to make a single good top and tip (plastic prep, heat up, cool down, remove squeeze out, prepare for tip mounting, machine tip, etc.) would merit a crazy price for the simple toy it really is. Maybe if the injector turns out to be a little more reliable, these could be souvenirs for visitors to the Cincinnati spinners who meet some minimum requirements like being a full member of this board, having visited the Hall of Fame, and having boomeranged Charlie Brown. ;)
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Maybe if the injector turns out to be a little more reliable, these could be souvenirs for visitors to the Cincinnati spinners who meet some minimum requirements like being a full member of this board, having visited the Hall of Fame, and having boomeranged Charlie Brown. ;)
Put my name on it! ;D I'll try to swing it this year, if not next, I promise! 8)
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WOW Johnm, that is pretty cool defenetelly a GREEN top, that journey tru plastic injection is fascinating, thanks for sharing
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neat.
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What are you using as your heat source to melt the plastic? I'd totally want to try melting some plastic down and turning it. Maybe even make a mold if I could get the time together.
Rob
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What are you using as your heat source to melt the plastic? I'd totally want to try melting some plastic down and turning it. Maybe even make a mold if I could get the time together.
Rob
I've got access to a scientific research gravity oven, but 180 C = 360 F is well within range for a common household oven. I have noticed a slight hot plastic smell (if you know what I mean) so use of the kitchen oven may be upsetting to other residents but I bet people are trying to give these things away for removal so a suitable 'garage' oven may be had for cheap. (Perhaps an appliance dealer that sells 'with removal' or a thrift store would sell and deliver a used oven cheaply.)
HDPE turns nicely with sharp tools, but with a nice smooth cutting motion on the wood lathe, super long tough/strong shavings are made that sort of weave together which can then loop around the tool and your arm and instantly wind up around the spindle possibly pulling you or the tool with it. I frequently stop to clean up before this happens but have had it wrap around the live center enough to lock it up. It is great fun and a nice change from the dustiness of wood and the uniform density/consistency is easy on the arms. If you slip (I have) it gouges easily :'( but it cuts so easily that catches are much less aggressive than with wood.
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I am away from the board for a few hours and look at what I miss!!! Wow is right. Now I need to figure out how to get down there before I go to San Antonio.
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Put my name on it! ;D I'll try to swing it this year, if not next, I promise! 8)
Written in ink! 8)
I am away from the board for a few hours and look at what I miss!!! Wow is right. Now I need to figure out how to get down there before I go to San Antonio.
Mike, Monday is a holiday but at least Bryan and I will be in the lab. Technically, you and John B. already meet the criteria so...
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oh la la !! ....John !
that's a great project : i like the way you recycle the tiniest bits to add up to the "sauce" ! i'm sure your mom has taught you some cooking :D ;)
and the molds are beautiful metal objects!
thanx for sharing your experiences and good luck for future ideas
how about a chocolate tops contest for the future local meeting ?
bye
jim
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wow! you guys do everything there, build the molds, recycle the plastic...
it is so impressive what skilled people can build.
now, thanks to jim, all i can think about is chocolate tops though.
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Well, now I have a few minutes. We just finished the annual Memorial day parade here in Miamisburg. It was fun to get our people on bikes and ride in the parade. I always ride my high wheeler. What a treat to do what is normally illegal....going back and forth across the road and even pedaling on the wrong side.
I won't be able to go to Cincy today but I am dreaming about a trip tomorrow morning. Wonder if any of the amazing C-City Spinner crew are around on Tuesday?
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Well, now I have a few minutes. We just finished the annual Memorial day parade here in Miamisburg. It was fun to get our people on bikes and ride in the parade. I always ride my high wheeler. What a treat to do what is normally illegal....going back and forth across the road and even pedaling on the wrong side.
I won't be able to go to Cincy today but I am dreaming about a trip tomorrow morning. Wonder if any of the amazing C-City Spinner crew are around on Tuesday?
Sounds like you had great fun this morning! Why not make it two days in a row? Tuesday would have been a normal work day for us but with the possibility of Mike stopping in it could be a great day. I believe everyone should be around for some spinning action.
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hey John, What are you using for tips?
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hey John, What are you using for tips?
Before they made it to a dumpster, I grabbed some rusty old laboratory ring stand posts from which I machine the tips. They are just regular mild steel so without care they will rust again.
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ultimate hardcore modder-creator! salute to u! love those tops u've created, they're beautiful!
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Found this info on melting/molding plastic just incase some of you wanted to try it out:
http://www.instructables.com/answers/Expertise-needed-on-melting-and-remolding-plastic-/ (http://www.instructables.com/answers/Expertise-needed-on-melting-and-remolding-plastic-/)
Important info:
http://www.instructables.com/id/HomemadePlastic/ (http://www.instructables.com/id/HomemadePlastic/)
She melted HDPE plastic bags in a pan on the stove, and successfully molded them into a wheel for a robot.
HDPE melts at 265 F (often a bit lower), while PP doesn't melt until 320 F. But the plastic chips you were using might not have been polypropylene. If they were one of the "thermosetting" polymers, they wouldn't ever melt at all, just like you can never melt a hard-boiled egg.
Any of the plastics with recycling triangle numbers from 1 through 6 are "thermoplastic" polymers; and can (at least in theory) be melted, molded, cooled, remelted, etc. indefinitely, like a ice cube rather than a hard-boiled egg.
HDPE (#2) and LDPE (#4) have the lowest melting points and emit little or nothing in the way of fumes. And since they are both the same polymer (polyethylene), they can be melted together.
PP (#5) melts at 320 F, but may sometime have additives that emit harmful fumes.
PET or PETE (#1) has little or nothing in the way of fumes, but doesn't melt until 500 F.
PS (#6) melts at 465 F, but may often have additives that produce fumes that are much better avoided.
PVC or V (#3) melts around 220-265 F, but always produces very nasty, harmful, dangerous fumes. Don't try this at home, kids. DANGER, WILL ROBINSON! AVOID AVOID AVOID.
I'm considering giving the turned melted plastic block a try. I don't actually purchase milk from jugs but I noticed that a number of my garden plants came in big #2 black plastic tubs and I found a cool silver tub as well ...too bad I'm not a Raiders fan :)
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Very good info SQ. Thanks!
I look forward to seeing your results.
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She's a hot momma you know ;D
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Thanks for the research SQ, the idea of melting and turning some HDPE really turns me on. In a makin' stuff kind-of-way.
I don't actually purchase milk from jugs...
I have to ask, how do you get yer milk?
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I can see my top in the very first picture on this thread. I am now the proud owner of the scarlet and gray Ohio State top on the far left of the colored tops. Can you see my cute little baby? He is such a beautiful little top and I am the proud papa!!!
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HDPE melts at 265 F (often a bit lower),
Nice list of melting temps and dangers. However, the melting temperatures are just that--the temperature of the phase transition between a solid and a liquid. For HDPE (its the only one I've worked with) the melting temp of 265F is rather low for a 'working' temperature of the material. The plastic gets sticky at 265 but doesn't flow together to form a single piece of plastic (at least in a tolerable amount of time)--it basically becomes a collection of lots of pieces just stuck together as you can see from that 'instructable' project.
(http://www.instructables.com/image/FK0IOR8FM7WGPBJ/Plastic-Smithing.jpg)
A block of skeletal material like that is not something I'd want to spin quickly in my lathe or try to cut, much less try to throw as a top. I've found that a temperature around 360 F allows the material to flow together nicely under just the force of gravity to form a single piece of stuff. HDPE at 360 degrees is still ridiculously viscous and there is no hope of pouring it as someone might cast iron or bronze or chocolate. Cooling from this temperature, the block will shrink a lot in an uncontrolled way so the resulting block will be smaller than the container and will have an unusual shape to round out as you start turning (be careful of catches). For me there always seems to be voids in these large blocks. Sometimes there has been a single large void, and other times there have been multiple small cylindrical voids. I'm not sure why these form, maybe due to trapped air during the melt or perhaps just a shrinking event. Regardless of the source, hidden voids can be a real surprise while hollowing out a top.
Good luck to those who try this.
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I don't actually purchase milk from jugs...
I have to ask, how do you get yer milk?
[/quote]
Well Neff, I know you're just dying to hear me say that I have my own Jugs, and as mentioned by Poptop, I am a "hot momma", but alas.....I'm of the non lactating/childless variety......and, since I only consume milk in limited quantities...on my cereal.... I buy my milk in cartons.
Short answer: From COWS! (Proceed to spin your top) Oh btw, "Happy Cows Come From California"
John, thanks for the additional info. I wasn't imagining my melted blob/mass would look much like this "skeletal" donut before I attempted to turn it. Perhaps Neff would like to throw this donut ;) I was hoping for something much more evenly congealed and uniform, but perhaps that's just wishful thinking.
I would love to see a photo of one of your final melted blocks if you should turn another. Do you think it would be possible, or helpful even, to pound the melted plastic mass as one might do to cake mix to prevent air bubbles/voids or is the plastic not liquid enough?
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I would love to see a photo of one of your final melted blocks if you should turn another. Do you think it would be possible, or helpful even, to pound the melted plastic mass as one might do to cake mix to prevent air bubbles/voids or is the plastic not liquid enough?
Here's a pic with a container full of raw material chunks which gets melted and additional chunks added several (maybe 6) times next to a cooled 'fully' combined block of HDPE plastic in a similar container. You can see the surface is continuous and smooth but not a nice uniform shape. The shrinkage is reasonably visible. The inner diameter of the container is about 4 inches and while at temperature (360 F) the material fully fills the diameter. The shrinkage is so nonuniform around the circumference of the resulting cylinder that after cleaning up the outer diameter, I get a suitably round turning blank to make a top of 3 inches diameter, which is the nominal size of the white top in the size comparison picture posted earlier.
(http://farm5.static.flickr.com/4023/4670666510_bf0b0a514f.jpg)(http://farm5.static.flickr.com/4002/4670039765_df6c092f0b.jpg)
Not going to high enough temperature will probably result in a very skeletal block unless some real pressure/compressing force is used. Here's my very first test of the mold with milk jug plastic. Of course I underloaded the base form (due to fear of terrible adhesion) but regardless, the material didn't flow together under gravity and it really didn't mash together very well when the inner part of the mold was pressed in.
(http://farm5.static.flickr.com/4056/4670039939_c39f1a3e9f.jpg)
Pounding may do something, but it probably will be rather difficult. Even when hot, the material is very 'stiff' and when removed from the heat, the surface quickly cools and solidifies thus making it hard to work. On the top of the block you can see neat tight 'swirls' of red/white/blue which are due to my stabbing a rod into the melt several time in the hope of venting and collapsing any large voids--don't know if it worked yet, may have created more. I think stabbing is still a good idea because it provides a test of the melt in the center. The material melts from the outside to the inside so the surface can look very nice while the chunks in the center are barely warm and therefore still just individual chunks. I think with a little experimenting you can not only wish for reasonable uniformity but you can expect it, but don't be disappointed when they aren't perfect.
Maybe Neff will be making his own custom discs for golf. :)
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Maybe Neff will be making his own custom discs for golf. :)
Well if that's what you're thinking, maybe we should! ;D
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John, thanks so much for the photos. Very interesting and helpful. I love the red/white/blue, awesome for a 4th of July top :)
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Mike left a Cincy recycled black top (got chocolate?) on lease until I fulfill the conditions for ownership. I love the shape of this guy! That mold is perfect! The tip regens and wirewalks well (I just did staircase to heaven). If this was a commercial top it would be hot regardless of the green perspective which just adds extra coolness to it. I am impressed!
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Mike left a Cincy recycled black top (got chocolate?) on lease until I fulfill the conditions for ownership. I love the shape of this guy! That mold is perfect! The tip regens and wirewalks well (I just did staircase to heaven). If this was a commercial top it would be hot regardless of the green perspective which just adds extra coolness to it. I am impressed!
Glad you like it. We've had great success with them, in particular Tai-Min can now rollercoaster with ease, Aaron is really progressing on suns, and Bryan and I can quickly regen (Joker Choker mainly) to well beyond maintenance speeds to do double and Mexican wirewalkers and corkscrews. I think part of our progress is due to a lack of fear of damaging or breaking our pressous tops since these already have some flaws from the casting process, they are tough and we can make more.
In addition to the guilt :P it may give to encourage your trip to Ohio, I had an additional motive to sending one along with Mike:
In the last pic, the shape reminds of a Gates.
Perhaps you could snap a pic of them side by side for comparison.
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Your wish is my command. Here it is:
(http://www.ta0.com/museum/images/miscellaneous/got-chocolate_gates.jpg)
The shape is indeed similar to a Gates and I have always been a big fan of that top. But, maybe because of the open crown, the top it reminds me when I have it in my hand is the STB.
Wow! The Cincy group is progressing fast in their playing abilities. I better go there soon or I will not be able to teach you anything!
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Thanks ta0, nice shot. That's a perfect angle to display some of the shrinkage problems. In particular the profile of the cap in the mold has a circular shape which continues along the body to blend to a tangent line extending to the tip (thus the shape would be an even closer match to the Gates), but the plastic has a rather collapsed contour on the cap giving it a shape slightly reminiscent of the Mexican tops. Less obvious are the shorter overall height, smaller maximum diameter, and slightly larger angle to the body. Also the cap should install with a slight press fit but it actually required a single wrap of tape to compensate for contraction.
The mismatch between the top body and the steel tip is my fault. I typically have a generic tip which I intall on each top just to test the balance to determine if that individual top 'deserves' its own tip and then make a tip to match that top (no real mass production here because the end diameter of the plastic is generally not consistent) but the initial balance of that particular top was really nice with no adjustment so I refused to pull the tip to replace it. If/when you pull the top apart, that internal tape ring may slip off and need to be replaced. Also you should somehow mark (on the non-black tops a Sharpie line inside works but may not show well on that one) the orientation of the cap so it can be reinstalled in that balanced position--try the cap rotated to see how bad the balance can be due to the unsymmetrical shrinkage and random voids.
If you make your own preferred style tip, the mounting hole is tapped for 10-32 thread.
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Wow! The Cincy group is progressing fast in their playing abilities. I better go there soon or I will not be able to teach you anything!
I have a feeling, call it a hunch, that I still have a lot to learn from a master spinner ;)
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Making your own trompo, in plastic, wow now thats impressive
Very very nice............
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and I love the matching milk cap button
Turns out that the milk jug cap buttons have a lifetime. Today two of them failed by cracking radially outward from the center hole allowing the knot to pull through. Kind of a surprise to see the top fly away when you know you remembered to hold on to the string during the throw. :o I may consider casting a button, that is a little thicker and hopefully more robust.
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With Aaron the top destroyer administering the death blow, our combined efforts have finally broken one of our HDPE tops. The ring which aligns the cap and base snapped completely off the cap. This orange material from a bread crate seems to be a little more brittle than some of the others since when cutting it into small bits, it tends to break and blow apart at the end of the cut rather than cut all the way like most of the rest of the sources we have. The break revealed a number of voids in the casting which probably contributed to weakness in that region. It had survived a tremendous amount of abuse from all of us and now will hold a place of honor on the shelf.
(http://farm5.static.flickr.com/4132/4988852484_3e58007bac.jpg)
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I'd call that good data...sounds like those bad boys take a beating! Did you give 'em a name besides HDPE tops?
I'm wondering if resin could be used in the mold? Be cool to cast some like the old Duncan Mardi Gras Yo-Yo with big colorful chunks and spangles.
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Considering all the trouble players had over the years with tops breaking, it is amazing how durable your recycled tops are. I think now there is no excuse for manufacturers not to make indestructible tops (at least fixed tip).
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Did you give 'em a name besides HDPE tops?
I'm wondering if resin could be used in the mold?
I know it's not very clever but at this point I guess we're locked in on HDPE.
I'm reluctant to use other stuff in the mold for fear of adhesion and then damage to the mold during removal. Call me a coward but for now I'm sticking (pun intended) with what works and what I know.
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If it aint broke...
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I am totally impressed. Milk jugs to tops. I love it. ???
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It is quite impressive! It was a thrill for me to see the whole process.
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I am just back from a college visit for my step-daughter. We drove to Huntington, West Virginia and I didn't see any top action anywhere along the way in Ohio, Kentucky or West Virginia. I did walk by their physics building and wondered if they could ever come up with some of the top spinning stuff like the UC folks. Nope. I don't think so.
This was not one of my better top spinning adventures. Except for RunBMC, I don't know of any top spinning activity in Kentucky and West Virginia seems totally topless right now. I hope there is more happening that what I just witnessed.
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Decided to re-read this post after Dick Stohr's visit to UC... 8) B)
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Decided to re-read this post after Dick Stohr's visit to UC... 8) B)
and the Apex visit: http://www.ta0.com/forum/index.php/topic,1295.msg13043.html#msg13043 (http://www.ta0.com/forum/index.php/topic,1295.msg13043.html#msg13043)
So who all happens to have a milk jug top?
Hopefully I can make it to UC one day.
and also Whirled Top festival...
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So who all happens to have a milk jug top?
Because the blow molded plastic of milk jugs is not great for the casting technique I use, only myself and ta0 have a version made from milk jugs. ta0 received his from me as a gesture of thanks for repairing Autograph at 2010 worlds, to allow several extra players to spin it after it suffered a significant fracture. The other tops distributed are from sources of injection molded plastic like 5 gallon buckets.
Although about 20 people have HDPE tops, not all of them are active spinners and among the spinners, not all of them have met the requirements, but those who have met the requirements as of 12/14/2011 include in no particular order,
johnm
Hemingsoft
physboy2357
Mike Hout
John Beuchele
ta0
Apex
Dick Stohr
WaxyAxle
Watt's Tops
Eli Hickerson
Shootist
For the record the requirements have been modified slightly to include the option of substituting bomeranging Autograph for Charlie Brown since visits in winter may not accommodate throwing CB and you may have already thrown Autograph at worlds for example.
The requirements to be filled in no particular order and at any time are
1)visit the UC spinners at the University of Cincinnati, Cincinnati, Ohio
2)be a full member of this forum == 30 posts
3)visit Mike Hout's Hall of Fame and TOPLAND in Miamisburg, Ohio
4)boomerang Charlie Brown or/and Autograph
Coming to the Whirled Festival of Tops in August in Miamisburg and before or after making the trip to Cincinnati is a great way to get most of these requirements fullfilled. ;)
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Hey John, any chance you might want to try melting/casting some Yeti fur?
Say the word and it's yours...
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Hey John, any chance you might want to try melting/casting some Yeti fur?
Say the word and it's yours...
Thanks for the offer but I cannot stand the smell of burning hair. ::)
In particular from Dupont (http://www2.dupont.com/Plastics/en_US/assets/downloads/processing/DELRIN_Mold_Guide_11_06.pdf)
As with any acetal polymer, Delrin®, when overheated, can
discolor and form gaseous decomposition products, which are
largely formaldehyde. Low levels of formaldehyde emissions
can also occur at typical processing temperatures. Repeated
exposure to formaldehyde may result in respiratory and skin
sensitization in some individuals. Formaldehyde is a potential
cancer hazard.
Thus to avoid more exposure to nasties at work than I already get, I'll continue to use HDPE (recycle #2) and LDPE (recycle #4).
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Yeah, not wanting to kill John with toxic gasses...that would be bad.
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The requirements to be filled in no particular order and at any time are
1)visit the UC spinners at the University of Cincinnati, Cincinnati, Ohio
2)be a full member of this forum == 30 posts
3)visit Mike Hout's Hall of Fame and TOPLAND in Miamisburg, Ohio
4)boomerang Charlie Brown or/and Autograph
This is my 31st post ;D
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Go WaxyAxle!!!
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rereading this thread all i can think about is that i wonder how slowing down everything having to do with heat would effect the tops being created... i mean, when you fire ceramix you have to step down the heat slowly or it breaks don't you? i wonder if stepping down the heat would effect how much the plastic shrinks...
also i wonder if when you start to melt the plastic, if you did it at a slower rate over a longer period of time, i wonder if it'd have fewer air pockets/voids...
i know if you blow glass you have to put it in a kiln so it's tempurature can be lowered at a controlled rate over a long period of time or the glass will shatter.
i know if i'm dying fabric i apply the dye in hot water and then shock the fabric by putting it in cold water so the fabric will quickly shrink and the dye will hold more sturdily (is that a word?)...if quick temp changes can effect (affect?) that so much, i would think the ideas would be similar... as far as bonding metal goes what's brazing again?
you math and science kids should know more than what i wonder, so i assume if i'm off, you can correct any of my wrong thinkin'... or maybe i'm just sooo lacking communication skills that all of my thoughts only make sense to me and an attempt at explaining what i think is futile (much like resistance).
and on a somewhat different note: who cares if it makes a thorough proper mix or not: i think you should try mixing higher densities of materials with lower densities of materials... a sponge form built around/within/through a sponge form... if i were you i'd be finding out what happens when i mix different hotglues with the milk bottles and other things you've been melting...
you kids make me wish i was super rich.
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I have been reading this thread with huge interest, I absolutely love the idea, and the results are impressive in their quality (visually speaking, of course, that's all I can observe from here...).
Then I found out about the requirement list, and my hopes of ever getting one fell...... I wonder if it would be possible to have an international requirements list... something one can fulfill without having to live in the US? ::)
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I wonder if it would be possible to have an international requirements list... something one can fulfill without having to live in the US? ::)
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If Ta0 won't add a like button to this forum I"ll make my own! ;)
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I wonder if it would be possible to have an international requirements list... something one can fulfill without having to live in the US? ::)
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If Ta0 won't add a like button to this forum I"ll make my own! ;)
jaaaaajaaaaa jaaaa ;D ;D ;D ;D ;D
I was too tight awhile in button I like of it. ;D ;D ;D ;D ;D
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i wonder if stepping down the heat would effect how much the plastic shrinks...
also i wonder if when you start to melt the plastic, if you did it at a slower rate over a longer period of time, i wonder if it'd have fewer air pockets/voids...
Slow cooling may give bubbles more time to get out. Also avoids internal stresses that could separate the material and create air pockets. On the other hand, the final shrinkage is given by the end temperature and the material, not by the rate of cooling.
If Ta0 won't add a like button to this forum I"ll make my own! ;)
If I added the button people would be too lazy to post. ;)
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His work is seriously impressive!
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rereading this thread all i can think about is that i wonder how slowing down everything having to do with heat would effect the tops being created... i wonder if stepping down the heat would effect how much the plastic shrinks...
also i wonder if when you start to melt the plastic, if you did it at a slower rate over a longer period of time, i wonder if it'd have fewer air pockets/voids...
and on a somewhat different note: who cares if it makes a thorough proper mix or not: i think you should try mixing higher densities of materials with lower densities of materials... a sponge form built around/within/through a sponge form... if i were you i'd be finding out what happens when i mix different hotglues with the milk bottles and other things you've been melting...
For melting, the most effective way to reduce air trapping is by adding small amounts of material at a time to minimize the trapping events and minimize the material through which any trapped air must travel to escape. Degassing the melt with vacuum before adding more material also helps. Of course injecting a continuous flow of melted material would be better.
For cooling as ta0 commented, the thermal contraction is a function of temperature so the high temperature at which the form is assembled is what controls the amount of contraction experienced. Because my mold is square and not round, the cooling can be nonuniform with the metal corners holding more heat than the narrow sides. Thus stepping the temperature down slowly reduces the variations around the top and helps promote uniform shrinking but does not reduce the amount of shrinkage.
The HDPE plastics I’m using have close but varying densities. A thorough or proper mix of multiple colors helps with a uniform distribution of mass which promotes better balance for the top. If PE plastics of significantly different densities are mixed (like some HDPE with some LDPE), the different thermal contractions result in inconveniently textured surfaces. Mixing different types of plastics with significantly different melting temperatures may result in decomposition of the one with the lower melting temperature when subjected to the high melting temperature of the other one. Additionally the various plastics may not bond to each other.
There are lots of possible improvements to test and think about, however, most of them take more time to implement and increase the time and effort required to make a top. One thing I hope to eventually try -- based on some descriptions from Spinningray about reinforcing his large tops on the inside with (I think) fiberglass -- is to melt the plastic with some type of cloth liner becoming embedded in the plastic.
In general though, my process already requires an absurd amount of time to produce a flawed top which still requires machining to clean it up and make the cap fit the body not to mention the tip. As long as there are great playing tops for $20 (or even $100) available, this technique is a ridiculous way to get a top to play with. I do it because I have more time than brains and get some satisfaction from the process.
Then I found out about the requirement list, and my hopes of ever getting one fell...... I wonder if it would be possible to have an international requirements list... something one can fulfill without having to live in the US? ::)
I recognize the geographic/economic discrimination created by my requirements to ‘earn’ one of these tops, however, my willingness and motivation to invest the time and effort to fabricate these tops is to provide a token somewhat unique 'thank you' to those spintop enthusiasts willing to commit their time and travel expenses to visiting and supporting top spinning in Ohio, particularly my favorite event in Miamisburg.
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Fair enough. :)
I'll just have to admire the pics for now. ;)
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Thanks johnm, for that good explanation about all the things you go through for your tops. I have seen it and I have thought about it but it still makes me appreciate my "buckeye top" all the more. Of course, as I always say, when you have bad tops you can't do anything with or old scraps, the Hall of Fame will always be glad to take them to add to your exhibit!
Also, thanks for your plug of our event. We are hoping the 14th one on the 24th of August in 2013 will be the best yet!!!
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It is an incredible work, I admire his work and understand his way of awarding his tops,
We will continue dreaming many of these nice tops, :'(
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Hey Mike "The Earl of Whirl"
Save me and Eli a spot at Bullwinkle's, may have to make another Ribs and Spintop run to Miamisburg, Ohio.
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Looking forward to another visit from Shootist and Company. People took our event more seriously when I told them that spinners were coming all the way from Alabama to attend! If all goes well, I hope to see you twice next year......at worlds and in Miamisburg. That would be another good year like 2012!!!
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Then I found out about the requirement list, and my hopes of ever getting one fell...... I wonder if it would be possible to have an international requirements list... something one can fulfill without having to live in the US? ::)
I recognize the geographic/economic discrimination created by my requirements to ‘earn’ one of these tops, however, my willingness and motivation to invest the time and effort to fabricate these tops is to provide a token somewhat unique 'thank you' to those spintop enthusiasts willing to commit their time and travel expenses to visiting and supporting top spinning in Ohio, particularly my favorite event in Miamisburg.
Aaaallright.... I guess the impossibility for us to have one, despite how much we would like to, is exactly the point... Our drooling is demonstrating and highlighting exactly how exclusive they are... ;D
Fantastic work, hopefully I'll be able to at least SEE one, sooner or later! ::)
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Waiting for plumbers to come and working around the house today so I am taking the opportunity to continue my work with HDPE. I am happy to have found this thread again to try to better understand this material. I have made several clumps of HDPE, trying for the shape of a cylinder so I can turn it on a lathe. Some of my finger spinner tops have come out in pretty good condition and some have had some substantial air pockets. Still, people seem interested in what I am doing when I show them my wood and HDPE creations.
Has anyone else tried working with this material. It is especially good to play with it on a cold day and while something is cooling, to use the heat it gives off for comfort!!!
My youngest son will be here in a week and we have talked about attempting some fun things with this while he is here.
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It is kind of interesting to cut out designs from this material and melt it to other pieces. I made a couple snowmen plus a giraffe!
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My granddaughter loves the snowman and the giraffe. Yet, I think what she likes more than anything is the display of three Ohio State colored tops made by johnm. Each one is a different size and she plays with them several times each day. She has been overheard to talk to the big top as if it is the dad with the medium size top as the mom and the smallest top as the baby!
Another one who loves my plastic bottle creations is our dog, Gracie. She thinks that every cylinder of HDPE I make for the lathe is something I have made for her. I have let her have a few of them and she loves to prance around with it and then chew on it for a while before I rescue it for its real purpose.
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I love to hear about this new facet of The Earl as a craftsman . . . a top/toy maker! 8) 8) 8)
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More small Tops. Very nice work. Mold is the best way to go.
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My granddaughter loves the snowman and the giraffe. Yet, I think what she likes more than anything is the display of three Ohio State colored tops made by johnm. Each one is a different size and she plays with them several times each day. She has been overheard to talk to the big top as if it is the dad with the medium size top as the mom and the smallest top as the baby!
Another one who loves my plastic bottle creations is our dog, Gracie. She thinks that every cylinder of HDPE I make for the lathe is something I have made for her. I have let her have a few of them and she loves to prance around with it and then chew on it for a while before I rescue it for its real purpose.
sounds like paradise on earth
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Thanks for your comments. This HDPE has been a very special gift this Christmas......to myself. Family members and friends are giving me their recycled bottles and I am having lots of fun showing others my latest bit of progress. It is so wonderful to have this kind of activity to get me away from work stress!!!
I have been reading the slingshot forum but not because I am interested in slingshots. They have a long thread about making HDPE which dwarfs what we have been talking about here. I had no idea there was that much interest in slingshots! There are oodles more slingshooters out there than top shooters, which I never could have imagined. If anyone is interested, here is a link to 33 pages of information about HDPE:
http://slingshotforum.com/topic/22723-hdpe-sheet/
After reading some of this early one morning (when I couldn't sleep) I ran across the idea about making bowls with this stuff. I turned the oven on and soon I had some bowls to put some Christmas candy in. It got me to thinking about other possibilities.......like fans and frisbees and other toy possibilities.
I love the idea that I am slowly moving into the realm of toymaker. I always admired Don Olney.
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I got a nova chuck for my lathe for Christmas. Many thanks go to my lovely wife!!! I played with it a little today but not too much. This most certainly opens the door to many more possibilities with turning.
Wow, I still have so much yet to learn!
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Wow! Very nice of Dawn! Did you leave a Woodcraft's catalog with a large circle drawn with a marker laying around? :)
Is that a 4-jaw chuck? You are getting fancy!
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Neato. I use Nova chucks and they're super useful. They can make life at the lathe a lot more interesting.
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I am still a rookie but, boy, am I am happy rookie. I feel myself making progress every day and picking up new little tips all the time. This is the life I love - where I can feel myself moving in a positive direction and know there is so so much more for me out there to still discover.
Last night I got to finally get going with my new nova chuck. It is a four jaw chuck and it feels miraculous after having to deal with that pointy drive center for so long (and having to take it out and hammer it in every time). The chuck holds the wood (or HDPE plastic cylinder) really well and that opens up all kinds of new possibilities. Now my tips look so much better!
Dawn is pretty sharp. I did have a catalog and the exact number but she was all over it long before that. She is the greatest. Last night she watched the Harry Potter marathon and I turned ten tops in the basement. This morning I looked at ones that needed a touchup and that new chuck allowed me to fix them up quite nicely. I feel like I just made a giant jump in what I can do. Poptop was right about me needing a nova chuck!!!
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Here are some of the finger spinners I have made out of HDPE. It has been more fun than I thought!!!
(http://ta0.com/Button-n-String/Hout/Mike-hdpe.jpg)
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Nice swirl Earl, they are out of this world!
Now give'em a twirl and post a video Earl!
Keep up the great work 8)
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Very neat Mike, keep turning them out!
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Nice Work Earl, Look forward to see them.
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Here are some of the finger spinners I have made out of HDPE. It has been more fun than I thought!!!
they look literally delicious
(http://m.memegen.com/2skn9u.jpg)
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That is the true meaning of upcycling (http://en.wikipedia.org/wiki/Upcycling)!
they look literally delicious
Well, they DO look like candy!
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they look literally delicious
Well, they DO look like candy!
i know right, but i also just cant seem to stop seeing a red maple leaf in that white one in the foreground..........patriot jack is patriotic much ::)
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They look great Mike!
I imaging that turning up-cycled plastic is really easy on your tools too :)
less sharpening I'd think.
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Yes, this up-cycled plastic is easy on the equipment. It is also kind of fun to turn......until you hit an air pocket!
The designs are fascinating to look at even when one is not throwing. I see lots of different designs......like the red maple leaf!
Little pieces of red and blue hdpe look so much like candy that one person in the congregation actually put it in their mouths and were ready to chew it (before I stopped them).
If Chuck Norris approves my work then...............wow! Thanks Jack!!!
Did anyone notice the long red and blue top at the back? I was waiting for someone to ask if it spins. It doesn't. But I went out and bought a large washer and fit it over the bulb end and now it spins!
Also, the yellow, red and white top in the back to the right is a take off of a Philippe model that spins on one's finger. I hope it was OK that I tried to imitate one of Monsieur Dyon's finger spinners.
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Hey, you are already experimenting with unconventional designs! That is great!
In theory the tall top would spin, if you could spin it fast enough (assuming it is balanced), but probably faster than any fingers can achieve.
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Very cool, Mike!
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Thanks Neff.
I have a new question about HDPE. I have heard that what is used for milk jugs and water jugs is called blown HDPE. Does this just refer to the process used to make the objects or is the plastic of a different quality? I must admit, it seems that the HDPE from milk/water jugs is easier to work with.
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I have a new question about HDPE. I have heard that what is used for milk jugs and water jugs is called blown HDPE. Does this just refer to the process used to make the objects or is the plastic of a different quality? I must admit, it seems that the HDPE from milk/water jugs is easier to work with.
I am guessing the it refers to the fabrication of the object by blow molding. But perhaps they add some additives to the plastic to make it flow better on that process so the plastic could be different :-\
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Since Mike asked his question about blow molded verses say injection molded HDPE, I’ve been reading various information sources about polyethylene (PE). It seems to be an extremely complicated product in all its variations of production, additives, and manufacturing uses. The primary thing I’ve concluded is that I don’t know anything about PE. After playing with casting scrap HDPE and playing with the rotomolder, I fancied myself as a “novice” PE user. After reading more, I’ve down-graded myself to PE “enthusiast” and feel that the promotion to novice is far outside my potential.
The following is what I think may be somewhat relevant to what we as top makers are doing with PE. It may be wrong but is what I currently believe.
First is the major classification of various forms of PE and in particular for items we are most likely to find as raw materials; the versions Low Density PE (LDPE, recycle #4) and High Density PE (HDPE, recycle #2). The density referred to here is the bulk property measured in mass per unit volume. By (some) definition LDPE has the range 0.91-0.94 gram per cubic centimeter and HDPE has the range above 0.94 gram per cubic centimeter. The bulk density is controlled by the extent of branching within the molecule. A low amount of branching and short branches results in a more linear molecule which allows for closely packed molecules and a high bulk density. Many long branches prevent the molecules from getting close together thus creating a less dense bulk material.
This schematic is copied from a Plastics Technology article by Michael Sepe ( link (http://www.ptonline.com/columns/density-molecular-weight-in-polyethylene) )
(http://d2n4wb9orp1vta.cloudfront.net/resources/images/cdn/cms/0612ptKHmaterials.jpg)
After selecting whether linear or branched molecule chains are appropriate for a particular application, the next most important independent feature is the molecular weight or basically the length of the individual molecule chains. For processing PE the molecular weight is typically discussed in terms of the material’s melt flow index (MFI) (or any of several similar names) which is a measure of the melted material’s ease of flow. Typically measured as the weight of the melted material that will flow through a certain diameter orifice per a fixed time while at a certain temperature and driving pressure. Longer molecules make the melt more viscous which measures a lower MFI, shorter molecules allow them to slip past each other more easily thus giving a higher MFI.
Here is a plot from the book Practical guide to Polyethylene which shows some of the possible combinations of MFIs and bulk densities for PE classifying them by density and fabrication technique or product.
Chapter 2: Basic Types
By Mihaela Pascu
From Practical Guide to Polyethylene
Polyethylene (PE) grades are mainly classified according to their density (Figure 2.1).
(http://images.books24x7.com/bookimages/id_21091/fig23_01.jpg)
Figure 2.1: Classification of PE grades. HDPE: High-density PE, MDPE: Medium-density PE, LDPE: Low-density PE, LLDPE: Linear low-density PE, ULDPE: Ultra low-density PE, VLDPE: Very low-density PE, LMDPE: low medium-density PE
Redrawn from Tecnon Orbichem. Copyright Tecnon Orbichem
Beyond these two parameters, bulk density and MFI, there is a huge parameter space of additives to optimize MFI and structural properties and to address a multitude of issues including color, gloss, antistatic, FDA, brittleness, ……………………
So regarding Mike’s question, blow molding, injection molding, rotational molding, etc. refer to processing techniques for fabricating parts. The PE used for these techniques have different characteristics tuned to make them optimal for that particular technique and part. The PE used for blow molding bottles (milk, shampoo, motor oil, etc.) has minimal branching making it HDPE and long chains giving it a low MFI, reducing the ‘sag’ of the bottle walls before cooling. The PE used for injection molding (soda crates, 5 gallon pails, etc.) has minimal branching making it also HDPE but has short chains giving it a high MFI allowing it to flow more easily into the voids of the molds being used.
Clear as mud, right. I recommend keeping simple notes about what recycled products you’ve found work for you and what doesn’t perform for your needs and stick with what works.
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Wow! Once again, I am super impressed with johnm information. I am not saying I understand it all, but I am impressed!
I do not have a mold or use a mold. That explains why I struggle with soda crates and 5 lb. pailes. Last night I made two more blanks of milk jugs and some colors from soap containers. I melt them into a flat pan then roll them up into a cylinder. In the next couple of days I will turn these blanks into finger spinners. Kids at our day care are begging for some more. I don't think they are impressed with my turning skill or the shapes I make. They just like the colors!!!
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Thanks John, but now my brain hurts........
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but now my brain hurts........
mine damn near exploded @-@
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Thanks for taking the time trying to distill all this information for us.
From the graph it seems the best PE for rotomolding are LMDPE: low-medium-density, and LLDPE: linear-low-density. I imagine few if any of the items you have recycled have been rotomolded themselves. From he graph, some injection molding uses LLDPE, so perhaps sometimes you got lucky. But obviously you achieved great results without the ideal plastic.
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This schematic is copied from a Plastics Technology article by Michael Sepe ( link (http://www.ptonline.com/columns/density-molecular-weight-in-polyethylene) )
(http://d2n4wb9orp1vta.cloudfront.net/resources/images/cdn/cms/0612ptKHmaterials.jpg)
I feel like this matches up with how you described attempts at working with ldpe...
And how long do you cook the rotomolder? have you thought about throwing some ldpe into it?
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For the recycled injection molded HDPE flakes I'm using, the time at melt temperature in the rotomolder is 70-75 minutes. I don't have much inventory of LDPE and am not aware of any significant source for which to look, so I have not tried rotomolding with it. I believe it would work just as well as the HDPE with an appropriate set of parameters. The product graph is displaying the most common techniques associated with specific variations of PE. It does not mean different PE types are incompatible with certain processing techniques, it just identifies the most effective and efficient combinations employed by industry.
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hi John and mike and the hdpe freaks
i've been sorting out the trash for a long time at home
sometimes collecting plastic caps for a local asso..;
now i've started looking at labels on caps
it seems that here in france/europe the HDPE is labelled as "2" in a triangle
"5" goes for PP (polypropilene?) "'4" is PVC and and there are also some labelled as LLDPE
some plastic containers are only labelled with >EU) number
i plan a melting session soon but in a park with a camping gaz ;D ;D
le plastique c'est fantastique !
jim
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I like that.............
le plastique c'est fantastique!
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I like that.............
le plastique c'est fantastique!
I believe the quote is from a song and refers latex not HDPE :D
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OK now that we have had the scientific explanation, maybe an little video of how to make a pen from LDPE will put some practical language is this discussion.
https://www.youtube.com/watch?v=BkAqgW3ilOE
Mike, this could give you some ideas about how to finish your finger tops.
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Ohh! Thanks Dick. I will have to look at this closer later. I see lots of good information here.
I just about have enough LDPE to make some tops but I never thought about a traffic cone for material!
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I think I have a new insight on HDPE. When I work the stuff from pieces I have cut, I can make some nicely colored objects but often they have air pockets in the very center. When I work from shavings (from previous cutting on the lathe) I notice that it is denser and it has fewer air pockets in the middle.
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For Christmas I got lathe. For Easter I am getting a cheap jigsaw. This should open the door to many more toy creations and some more top possibilities. Dreidels out of HDPE seem to be the most likely style I will first approach.
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can you mix HDPE with PP ??
jim
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I see your question was never answered, Jim. Sorry. I personally have not done that. johnm and I have mixed HDPE (#2) with LDPE (#4) but often now we keep them separate for our projects. LDPE feels a little different and seems softer to me.
Just today I found this video about making mallets from this tough material. I am posting it here because there is good information for us about the process before the handle is inserted. A tin can full of this melted material gives us a nice blank to lathe!
https://www.youtube.com/watch?v=v6ydNxqHhOE
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Just saw another episode of "How It's Made" on TV. That program shows fascinating information about how things of all shapes and sizes are constructed. Today they talked about HDPE tension fabric buildings. I had no idea that those giant tent like structures are made from HDPE!!! They showed how they use a special heat gun to weld big sheets of HDPE together for the roof. Wild stuff.
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Just had another interesting HDPE encounter. Actually, many encounters. They are all over the historic downtown of Miamisburg. There are a bunch of new green recycling/trash containers. They hold trash on one side and recycling odds and ends on the other. What caught my attention was the sign on the side of these large containers. It reads "made out of 1070 milk containers".
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So .... If you cut up a recycle bin, you could make tops!
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I think it would take some serious cutting and some serious melting. It might be beyond me, but I would keep those things away from johnm!!!
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HDPE continues to amaze me. Today was my first time off in a while so after I slept in as long as I could, I went into the kitchen and started melting HDPE in two containers. When I was done, I had two nice cylinders of green and white. I laid them on top of the refrigerator to cool. I don't think they were touching, but they were probably a half-inch or so apart.
This evening when I came home, those two cylinders were one inch apart and connected as if by an umbilical cord of HDPE!!! It is the weirdest looking thing and it is super solid. I might be able to perform some surgery with a saw but it is just too weird to mess with. It belongs in the Hall of Fame as it brings another story into that wild and woolly place.
johnm, how would you describe this phenomenon? I assume the heat from each cylinder caused a hernia of sorts and the material oozed out and connected.
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. . . but it is just too weird to mess with. It belongs in the Hall of Fame as it brings another story into that wild and woolly place.
:o ??? Do you have a photo? It sounds like some ectoplasmic flow. The Hall of Fame will be even more haunted now! >:D
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More like a Pahoehoe flow of lava.
http://www.youtube.com/watch?v=-QhU8eMR4IQ
Not a lot of details to go on, but I suspect that they were fairly firm but also quite warm when you let them cool outside the oven in the room. The material naturally cools from the surface as the mass looses heat to the air (and with whatever else it is in contact). HDPE is not a great thermal conductor so the inner volume can stay warm/molten for quite a while. As HDPE cools and freezes from the outside to the inside, it contracts or shrinks, thus increasing the pressure on the molten inner material. Sometimes the outer solid shell is weak enough to allow the pressure to break the shell and allow the inner molten material to be squeezed out thus releasing the pressure. I suppose the adjacent sides cooled more slowly due to the combined heat thus defining the weak part of the shell. The pressure may also have been high enough after contact was made to push the two pieces away from each other if a shell was frozen around the bridge so that it required less force to move the block(s) as the bridge lengthened instead of expanding the diameter of the bridge.
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You are right. It is probably more like a Pahoehoe flow of lava! The outside was hard enough and I thought I was finished. I have done this before where I put it on top of the refrigerator to cool. I was using a second pan, though, and for the first time was making two at once. So, once again for the first time, I had two sitting beside each other on top of the refrigerator cooling.
It is so weird to leave and come back later to see these two connected just like a large umbilical cord.......so solidly! It was as if they communicated some way and decided to stay together forever!!!
Thanks for the video. I thought the can was empty until the big explosion!
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I was wondering what would be a good way to share this information and ended up with this classic thread. There is a lot of good information here!
In the paper today are some amazing statistics. Since 1950 it has been determined that the industry has produced more than 9.1 billion tons of plastic. There is enough left over to bury Manhattan under more than two miles of trash. A leading expert says we are headed toward a plastic planet.
Of the 9.1 billion tons made nearly 7 million tons are no longer used. Only 9 percent got recycled and another 12 percent was incinerated, leaving 5.5 billion tons of plastic waste on land and in the water.
"The growth is astonishing and it doesn't look like it's slowing down soon," Roland Geyer said.