Belt drive 45rpm 8dg. Help?

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sameal
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Belt drive 45rpm 8dg. Help?

Post: # 47753Unread post sameal
Tue Sep 05, 2017 9:06 pm

Hi.

Im back working at the 8dg after moving it again. The 45rpm puck has been giving me troubles. The shaft on the slideplate has pitting where the felt sits in the middle of the puck, and the felt is pretty wasted too.

Im thinking i could belt drive the thing. Anyone have ideas or tried this?

The big hurtle would be getting a belt to move the wheel. I think that off the shelf gear could work if a spacer could be made to mount it. Then the whole puck mechanics could be bypassed
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audiocarver
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Re: Belt drive 45rpm 8dg. Help?

Post: # 47809Unread post audiocarver
Tue Sep 12, 2017 7:45 pm

That idler shaft shouldn't be too hard for a machinist to correct and or make a replacement.

I'm not sure on your lathe, but on mine from bottom to top, they have a plain washer at the bottom, the rubber idler wheel, felt/fiber washer, then the retainer clip. The shaft should be greased. Now, on my lathe, the rubber idler is for 78 instead of 45rpm.

There shouldn't be any felt in the middle of the idler wheel. This maybe where your problem really is. If the felt catches somehow while the wheel is turning.

Did you have that rubber idler reworked?

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rsimms3
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Re: Belt drive 45rpm 8dg. Help?

Post: # 47810Unread post rsimms3
Tue Sep 12, 2017 9:19 pm

The idlers for the 6 and 8 series have a ring of felt in the inner center of the idler that retains oil to keep the idler lubricated. I can't find a picture and I don't have my camera here at the computer.

As for the pitting, it sound like it's in the center of the idler shaft where the felt sits and doesn't contact with the inner part of the idler? You should be able to put any kind of good felt in there to retain the oil to keep things lubricated. I guess I don't understand the issue. Is the pitting on the idler shaft rubbing hard on the inner part of the brass idler itself?

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audiocarver
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Re: Belt drive 45rpm 8dg. Help?

Post: # 47820Unread post audiocarver
Wed Sep 13, 2017 6:06 pm

The only problem I would have with the belt drive approach is that there would be no way to uncouple the 45 motor from the rest of the gear train while cutting at another speed.

Presto has clutches inside the gear box that do this to reduce mechanical noise and drag from the other motors while one motor is selected to run at set speed.

In this case of the 45 speed, it is decoupled from when the idler wheel is disengaged from the filter flywheel and 45 motor shaft.



My comments about greasing the idler are from my experience with my Presto 8GV, which were set up to be greased instead of oiled and it is also mentioned in the owners manual for the 8GV.

My 8D and 8N lathes are set up the same, with felt stuffing inside the wheels to retain oil when oil is applied to the top hole of the wheel shaft.

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sameal
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Re: Belt drive 45rpm 8dg. Help?

Post: # 47832Unread post sameal
Thu Sep 14, 2017 11:11 pm

Yes the pitting is at the felt level. It doesn't cause any snag, but i lubed up the wheel with sewing machine oil and it doesnt spin too good. The fiber washer and clip are pretty worn out. The puck has been rerubbered but i gotta get it trimmed here soon.

That's a good point about decoupling. Crap! I dunno how id overcome that easily.

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