iTopSpin

Please login or register.

Login with username, password and session length
Advanced search  

News:

Author Topic: japanese  (Read 16786 times)

johnm

  • Ultrahero member
  • *******
  • Posts: 892
Re: japanese
« Reply #15 on: November 10, 2014, 09:05:17 PM »

During the recent sorting of Jack's sweet cache of Japanese top videos it seems this one about a bit of turning and painting of the Sasebo koma was lost (or placed where I have missed it).  The pile of blanks shows the marks of a drive center from initial turning between centers in what is likely a more conventional lathe for the western audience.  The lathe and jamb chuck used for finish turning and painting seems more Japanese style.

I suspect the "mass produced" blanks of Sasebo tops shown were made in one of the two ways shown in this kendama fabrication shop (sorry no tops but perhaps the NSTR police will allow it to pass due to the recent kentoppa videos  ;D ::) >:D ).  For smaller tops a single profiled cutter could be used as is done with the kendama ball.  If the size gets too large for a single simultaneous cut, a copier or tracer lathe setup can be used to cut a profile with a small cutter where its mounting carriage (cross slide) is tracked along a pattern cut to the desired profile as is done with the peg/cup part of the kendama.  Of other general fabrication interest, notice the fantastic shop made collet chucks and closers which allow the workers to remove and install work pieces without shutting off the lathe.

http://www.youtube.com/watch?v=fBLtetnlgwQ

A similar shop (perhaps the same?) and again kendama but I would be surprised if these shops did not also produce tops of one type or another, but maybe the kendama are the real volume money maker.

http://www.youtube.com/watch?v=e33YgRTQHrs

and a mom and pop shop where both tops and kendama are made without the more advanced technology.  A quick view under the lathe bench shows the foot controlled operation of the lathe, I assume to engage the overhead belt drive and to quickly break (stop) the rotation after disengaging.

http://www.youtube.com/watch?v=KQoj4WKYjbA
Logged

Jack

  • Demigod member
  • **********
  • Posts: 3389
Re: japanese
« Reply #16 on: November 11, 2014, 06:43:50 PM »

During the recent sorting of Jack's sweet cache of Japanese top videos it seems this one about a bit of turning and painting of the Sasebo koma was lost (or placed where I have missed it).  The pile of blanks shows the marks of a drive center from initial turning between centers in what is likely a more conventional lathe for the western audience.  The lathe and jamb chuck used for finish turning and painting seems more Japanese style.

I suspect the "mass produced" blanks of Sasebo tops shown were made in one of the two ways shown in this kendama fabrication shop (sorry no tops but perhaps the NSTR police will allow it to pass due to the recent kentoppa videos  ;D ::) >:D ).  For smaller tops a single profiled cutter could be used as is done with the kendama ball.  If the size gets too large for a single simultaneous cut, a copier or tracer lathe setup can be used to cut a profile with a small cutter where its mounting carriage (cross slide) is tracked along a pattern cut to the desired profile as is done with the peg/cup part of the kendama.  Of other general fabrication interest, notice the fantastic shop made collet chucks and closers which allow the workers to remove and install work pieces without shutting off the lathe.


A similar shop (perhaps the same?) and again kendama but I would be surprised if these shops did not also produce tops of one type or another, but maybe the kendama are the real volume money maker.

and a mom and pop shop where both tops and kendama are made without the more advanced technology.  A quick view under the lathe bench shows the foot controlled operation of the lathe, I assume to engage the overhead belt drive and to quickly break (stop) the rotation after disengaging.


ooooooooo! thanks for tposting that, i really found it interesting because in the last cl days ive been fooling with my kendama again, i now can understand why some kendamas come with dents even though theyve never been used lol throwing them around like that at the factory lol. i see your point about the single cutter for tops, but why wouldnt it work for large tops? i mean as long as you didnt go to fast and hard right? very interesting videos, i have saved them all for reference  ;)
« Last Edit: November 11, 2014, 09:35:24 PM by ta0 »
Logged

johnm

  • Ultrahero member
  • *******
  • Posts: 892
Re: japanese
« Reply #17 on: November 11, 2014, 09:13:47 PM »

i see your point about the single cutter for tops, but why wouldnt it work for large tops? i mean as long as you didnt go to fast and hard right?

In theory a single cutter could work for large tops but there are many things to consider when deciding the approach.  I'm no expert and have no experience with the process but I suppose a few things to consider are the available torque of the machine--at some point even for small depth of cuts, the contact length of the cutter will surpass the capacity of the machine.  The ability of the work piece to handle the lateral force without flexing or even dislodging from the supports.  The strength of the cutter for regions of large extension--near the tip region the cutter extends significantly compared to the widest part of the top unless a matching cutter holder is used.  Larger cutters cost more.  It may just be faster to quickly remove small amounts of material at a time in several passes than it is to remove large simultaneous amounts of material slowly.

I suppose for modern processing approaches to kendama and the like, these issues don't arise because the CNC systems are moving high speed router bits as the work piece rotates.

PS.  When quoting posts, you can edit inside the quote to remove portions that make your post cluttered such as the videos and any text that may be irrelevant to your follow up post.  :)
Logged

mailman

  • ITSA Jr.
  • Superhero member
  • ******
  • Posts: 622
Re: japanese
« Reply #18 on: November 12, 2014, 05:02:08 PM »

I find these wood turning videos (I've become slightly addicted to watching them since becoming interested in tops) absolutely fascinating.

I do NOT need a lathe.  I do NOT need a lathe.  I do NOT need a lathe.... ;D
Logged

Jack

  • Demigod member
  • **********
  • Posts: 3389
Re: japanese
« Reply #19 on: November 12, 2014, 09:20:37 PM »

I do NOT need a lathe.  I do NOT need a lathe.  I do NOT need a lathe.... ;D

mmmmmmhm keep telling yourself that  ;D
Logged

cecil

  • ITSA
  • Hyperhero member
  • ********
  • Posts: 1367
Re: japanese
« Reply #20 on: January 02, 2015, 09:21:28 PM »

I do have a koma now and I'm going to put a new tip in and make one of the rings on the top deeper where I can throw over hand, and trick with it. I like the style of the top.
Logged

ta0

  • Administrator
  • Olympus member
  • *****
  • Posts: 14235
    • www.ta0.com
Re: japanese
« Reply #21 on: January 02, 2015, 10:16:03 PM »

I do have a koma now and I'm going to put a new tip in and make one of the rings on the top deeper where I can throw over hand, and trick with it. I like the style of the top.

The top looks more Chinese than Japanese, so perhaps it is not exactly a "koma". But I am sure you'll get it to work to your liking.
Logged

Kirk

  • ITSA Jr.
  • Hyperhero member
  • ********
  • Posts: 1443
Re: japanese
« Reply #22 on: January 03, 2015, 11:51:42 PM »

Of other general fabrication interest, notice the fantastic shop made collet chucks and closers which allow the workers to remove and install work pieces without shutting off the lathe.
Looking at the first video (from  Reply #15 on: November 10, 2014) at 4:00 it seems that the collets are wood!  Is that how you see it?
« Last Edit: January 04, 2015, 10:10:04 AM by Kirk »
Logged