Split from ...
The first QSH tops I got are as well balanced as any delrin top. The second batch I got (with the new tips) are a mixed bag of OK to shakers.
More testing needed but... I removed the crown from my most shaky QSH bearing. Learned to throw it. (lefty backhand point down-ish) It is as smooth as silk.
Preliminary conclusion. The aluminum portion is is really great. The molded crown is not as consistent. So any balance weight should be focused on the crown.
More testing needed
Well, I did more testing. Each QSH that I spun without the cap was so smooth as to be silly. Furthermore all of the caps were out of balance in the same spot! (differing amounts) So far they are all out about 120 degrees clockwise of the gate when viewed from above.
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My Balancing Procedure:
Be sure the tape is smooth with no overlaps or bumps. Sometimes I use masking tape.
Spin the top in your hand
Touch it with a felt tip marker on the tape. (see blurry photo)
The spot of the mark is where to add weight.
For the QSH I can be sure that the cap is the problem.
So I add Gaffer tape to the outside of the cap just above the tape at the marked spot until the top is smoother.
Spin again an use a different color marker.
Add or subtract weight (gaffer tape) until the top is smooth. Rinse and repeat.
Now un-tape the top. Find the gate on the crown before separating the crown from the body. The gate is where the plastic flows into the mold. In bright light you will see a blush or a haze and you can feel a bump or a dip with your fingernail. It is on the edge where the crown mates with the body.
Mark gate with a dot from a felt tip marker. - CAUTION - use only DVD safe markers. Chemicals in regular markers will attack the plastic. Mark the body also. (With the QSH this may not be needed since the metal body is so consistent.)
Relocate the tape weights to the inside.
Reassemble with masking tape (only because it is really fast to do) and check. Note: for small tops the difference in diameter from the outside to the inside is significant so you will need to add perhaps 20% more weight. For the Trompo Grande and QSH size this is not as important (perhaps 5 or 10%)
2 wraps of 3M electrical tape to finish.
Do happy dance.
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Cheater procedure
open up the top
Add 3 layers of Gaffer Tape as shown in the other blurry photo (120 degrees from the gate CW from above, CCW as shown from below)
I guessed at 3 layers based on how shaky the top was.
Reassemble
Done
Do happy dance.
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Procedure for other tops
All molded plastic tops might have either or both pieces out of balance.
I put tape at the rim and tape in several sections near the point.
Drop the top into a trapeze. This way the top is the most free to shake because your hand is not damping the vibration.
Chase the precessing top with a marker. (takes practice)
Mark the tape from the side not above or below for best results.
add weights as above.
Notes:
* Gaffer tape is like high quality duct tape
* Even it you use sticky tack with an open crown top the marked tape will give you the right location for the weights.
* Sometimes the marked spot is a bit CCW (from above) of the place where the weight is needed. I think this is because the pressure of marker affects the vibration. I need to try a really soft marker. Japanese top makers use a soft paint brush.
