Replacing the rubber on an idler wheel

I found this on a website. Do people think this would actually work?

The problem with virtually all of these rubber idler wheels is the aged rubber is no longer soft, often has disintegrated, cracked, got a flat tire from 25-50+ years of pressure in a static position. If the idler wheel has any pulling power at all, it is likely to slip because the rubber has hardened. The rubber dip techniques (coating the outer edge with liquid rubber) is a temporary measure only. Some people try shaving the outer edge to get down to the softer rubber, this too is temporary and of course you have to make speed adjustments resulting from a smaller wheel.

Even some New Old Stock (NOS) idler wheels will have hardened over the years. More often than not the heat from nearby tubes will have accellerated the rubber aging process. Enough of my rant. I strongly recommend you replace the rubber with parts from a reputable dealer, however a typical idler will price out at $35-50 where you mail your old idler and the dealer sends you a rebuilt idler.

If you're a bit adventurous, you can do (AP-1) this yourself. The AP-1 Idler with new rubber has an outside diameter of 1 3/4", the inside hole .507 1/2" shaft on the aluminum wheel is .125, the edge thickness is .140. I know this is a bit out of the ordinary, but I remove the rubber and replace it with a thick neoprene washer (plumbing supply store) and hold it in place using the #30 (thick) Super Glue. I've written about this before, but there is an interesting chemical reaction between the aluminum idler wheel and neoprene, when you lay a bead of the thick super glue on both sides of the neoprene washer, it automatically forms a meniscus (concave shape) that firms holds the neoprene washer in place. I then shave the edge of the neoprene using an emory board, just hold it steady against the edge (it shaves the wheel to the correct 1 3/4" circumference and puts on a nice flat edge that will pull like a truck.

Neoprene will outlast you and the AP-1 phonograph. It stays soft too.

 

I don't know if it will work but the guy doesn't know what he's talking about when he claims a different diameter idler will affect speed. The idler diameter makes no difference.

Doug

 

Interesting solution up there, but too much work. I got a big fat rubber band (like around broccoli at the supermarket) and held it in place with little dots of superglue. Then I trimmed the excess with a razor blade. Works perfectly. There's also a place that will re-rubber an idler, but I forget the details.

 

It must. The bigger the idler wheel the slower the platter turns. Right?

 

Oh, you're right. I did my research. It doesn't change with the idler size. Interesting. And good news. That means I don't have to be so exactly working with it.

 

I had a Nakamichi RX-202 that had what looked like a faucet type o-ring on the idler wheel and worked just great, up until I decided to change all the belts and idler wheel with factory parts.....the factory 'tire" was more flat,which actually did not fit the 'rim" as nice as the o-ring.at least on mine it did. Huck

 

I used to try & grind them down to the softer rubber - but I would have trouble getting them out of round.

I ship them out to the Voice Of Music site (they can do most of the plain-Jane units) & they come back perfect. Was worth the $$$.

 

There are some caveats. In theory, the diameter of the idler makes no difference because it's all proportional. The idler diameter gets larger or smaller relative to the motor pulley but also to the platter so the result is the same as if there were no idler at all.

In practicality, it may make SOME difference as a result of friction changes with diameter change and other variances due to that diameter change but those factors are pretty minor.

The only way to get a consistantly round idler is to use a lathe. The idler needs to spin true and the cutter has to be kept absolutely stable so the cut is also true.

Doug

 

Soak the hardened idler DOT 3 brake fluid to soften it and your back to grinding records! May take overnight possibly.

 

Damn, and I just put it back together!

I tried the rubber band trick and the result was pretty horrific. Wow and flutter went nuts. It took me an hour and half of cleaning and sanding to get that damn crazy glue off! I personally cannot recommend that idea.

 

Sorry, man, that's just what worked for me.

 

There are two guys whom I can recommend for idler rebuilds:
http://www.terrysrubberrollers.com/
http://www.vintagelectronics.com/Rebuild.htm

 

Don't worry about it. You probably had a bigger idler. Mine was on a portable player. A bigger idler would probably respond less dramatically than a small one. Hey, it was worth a try. And now my idler is much better for me sanding it down!

 

Remove hard tyre and soak in this, the longer the better:


Won't hurt a thing. At worst, it won't save your tyre if it's too hard or screwed up.

Pour the balance into anything mechanical around the house that leaks oil (it does work as long as the offending seal is not mechanically damaged

Fix is "permanent"; no need for re-treats

Analogman