First turntable, got tractor flywheel. Bearings?

ak_47_boy · 16th January 2007, 11:36 PM

I am starting my first turntable. I got this perkins flywheel off ebay. It weighs 52lbs, has a 14" diameter, a 30mm shaft hole and is balanced.

In the first picture right around the hole is about 1mm higher than the rest. Is this bad? I may be able to get it milled down as a last resort. I could just modify a mat?

What setup would work best:

What about magnets? What kind like ring magnets? I am concerned if they are not centered or there field is not centered it will create a effect similar to spinning a perment magnet motor.

neutron7 · 17th January 2007, 02:05 AM

nice find on ebay. i bet the shipping was more than the flywheel itself!
how many teeth in that big gear? it would be cool if it happened to be the right amount for speed indicator

bottom bearing sitting on flats wont it wander around? i dont think it would be so great.

what about use 2 very strong neo magnets instead of the bottom bearings.

valveitude · 17th January 2007, 03:48 AM

Quote:

how many teeth in that big gear? it would be cool if it happened to be the right amount for speed indicator

Doesn't matter..set the strobe rate to match the tooth count

jrevillug · 17th January 2007, 11:19 AM

Quote:

bottom bearing sitting on flats wont it wander around? i dont think it would be so great.

All of your designs have this problem- there is nothing in any of them to stop the shaft sliping sideways. I would suggest that, if you must use BB races, that you use 2, with the BB as the vertical bearing.

However, a better bearing would be possible using a brass or even PTFE bush around a shaft- it wqould be far quieter, and as long as you have the platter level, it should not have too much side load.

James

YNWOAN · 18th January 2007, 01:34 AM

I strongly recomend that you do not use ball races and, as sugested, you must have a bearing at the bottom of the shaft - if not along the whole shaft with a heavy platter.

moray james · 18th January 2007, 04:26 AM

look for some babbit bushings that you can have precission machined to fit . They will be a lot quiter than bearings and have less play. Nice one lucky you!

16th January 2007, 11:36 PM	#1
ak_47_boy diyAudio Member Join Date: Sep 2006	First turntable, got tractor flywheel. Bearings? I am starting my first turntable. I got this perkins flywheel off ebay. It weighs 52lbs, has a 14" diameter, a 30mm shaft hole and is balanced. In the first picture right around the hole is about 1mm higher than the rest. Is this bad? I may be able to get it milled down as a last resort. I could just modify a mat? What setup would work best: What about magnets? What kind like ring magnets? I am concerned if they are not centered or there field is not centered it will create a effect similar to spinning a perment magnet motor.

18th January 2007, 04:26 AM	#6
moray james diyAudio Member Join Date: Aug 2003 Location: Calgary on the Bow	look for some babbit bushings that you can have precission machined to fit . They will be a lot quiter than bearings and have less play. Nice one lucky you! __________________ moray james

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17th January 2007, 02:05 AM	#2
neutron7 diyAudio Member Join Date: Dec 2003 Location: Toronto Canada	nice find on ebay. i bet the shipping was more than the flywheel itself! how many teeth in that big gear? it would be cool if it happened to be the right amount for speed indicator bottom bearing sitting on flats wont it wander around? i dont think it would be so great. what about use 2 very strong neo magnets instead of the bottom bearings.

18th January 2007, 01:34 AM	#5
YNWOAN diyAudio Member Join Date: Jan 2007	I strongly recomend that you do not use ball races and, as sugested, you must have a bearing at the bottom of the shaft - if not along the whole shaft with a heavy platter.

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