Car Record Player Parts / Machinist????

G-Man · Post by **G-Man** » Fri Feb 05, 2010 3:07 pm

Vince

Do you have a picture? One with a rule alongside would be interesting. It could be possible to investment cast a new one in aluminum, using the old one as a pattern. My friend has done a lot of investment casting. If it's not an ultra-precision part it could work.

Rolls Royce use the method to create aero engine parts with minimal machining.

http://en.wikipedia.org/wiki/Investment_casting

Soon I'm going to use this to replicate a replacement piston for my 350 Matchless. I would be happy to help you come up with something.

Depending upon the actual dimensions it may be better to laser cut from solid or rapid prototype using the new metallic systems. Selective laser sintering is th enew Gee Whiz way of making usable one-offs in metal straight from a CAD file.

http://www.protocam.com/html/metal-prototypes.html

G

greg78gs750 · Post by **greg78gs750** » Thu Feb 11, 2010 3:01 pm

i'm gonna throw this out there because it is a resource i have used....sometimes local community colleges have machining classes where they have an interest in "government projects"....i have gotten some parts made on cad/cam that would have been impossibly expensive otherwise....if you know anyone in this sort of system, its might be worth a shot....comes to mind only because i am going in to use the bead blaster at my local cc next week...i know some of the guys there from taking some welding classes....just an idea.

Vince Lupo · Post by **Vince Lupo** » Fri Feb 12, 2010 4:38 am

I'll try to do a photo of this either today or over the weekend. Might give you guys an idea of what's involved.

Vince Lupo · Post by **Vince Lupo** » Fri Feb 12, 2010 3:59 pm

Finally managed to do some shots of the gear in question.

It's made of thin aluminum, and there is a square magnet that's held in with a flat head screw. the brown stuff on the gear is some shellac that the record player repair guy had applied to see if that would help the gear 'grab' the rubber roller that this gear drives (didn't work).

mike1969 · Post by **mike1969** » Fri Feb 12, 2010 6:27 pm

Maybe a clockmaker could duplicate a gear like that.

G-Man · Post by **G-Man** » Fri Feb 12, 2010 6:40 pm

Vince

That looks pretty interesting. Am I right in assuming that the roller that this 'engages' with has gone hard and therefore there is slippage between the two?

Maybe you are looking at replacing the wrong part. If you could reface the roller with a soft material, would that help. I guess that there are no actual teeth on the roller an that the part in your photo just has serrations to improve the friction.

I would say that this is eminently fixable. Even just 'sharpening' those teeth on the periphery would help. It's just knurling after all. A fascinating piece if mechanism. That plain section is where the roller sits when this part isn't rotating.

Are you sure that the roller is driven by this. It would make more engineering sense if the roller drove this wheel, perhaps.

I've repaired a lot of cameras in my time and I would love to take a look inside this thing. Unfortunately, I'm rather a long way away. If there is anyway I can help you, I'd be happy to.

I'll be in NYC around third week of March.

G

Vince Lupo · Post by **Vince Lupo** » Sat Feb 13, 2010 3:53 am

Hmmm...well NYC is about 280 miles from here, so don't know if that's going to work. Very much appreciate the offer! And if you've repaired a lot of cameras, you'd probably be interested in some of the cameras I have in my small collection.

As far as the rubber roller goes, I had it rebuilt a couple of months ago along with the idler wheel (also rubber). So that part of the equation has already been taken care of. The problem is that someone in the past filed down the teeth in one area of this gear, and it doesn't have enough 'grab' at that part to complete the cycle of moving the tonearm out of the way, changing the record, and moving the tonearm to the beginning of the next record. If you look at the gear closely, you can probably see where the teeth are worn down more in one section than the rest.

And that's the frustration - I've gone to the trouble of having all this stuff done, and it's been going on 7 years to get this thing to work properly, and it's all come down to this part. That machinist quoted me $2000 to have the part made, so of course that's not happening. The only other alternative is that there is an entire record player for sale on eBay for $200 Buy it Now. It's a real fixer-upper, and there may be parts missing, but I was thinking of contacting the seller to see if he could check if this gear is there, and I would buy the unit. BUT, no guarantee that that gear is any good! So, it would be a bit of a gamble.