A Couple Ampex 440 Questions (Cory??)

SteveM

New member
I wound up with a new pinch wheel that has no bearings or stem to attach to the pinch arm. Is it possible to take those off of the old one to put on the new wheel and if so do you know how to take them off?

Also, do you know of a good place to find relay replacements? I think I have enough good ones but I'm wondering if there is a new make that you can use rather than the old ones?


:)
 
Last edited:
I've never worked on an Ampex, but I'll bet that to remove the old roller form the arm, you unscrew the cap on top of the roller, have a look inside, there is probably a cur-clip that you have to take off, then the whole roller and the bearings will come off the shaft. You then carefully knock the bearings out of the old roller and press them into the new one, then put the new roller on the same as you took the old one off.

Cheers
Alan.
 
I've never worked on an Ampex, but I'll bet that to remove the old roller form the arm, you unscrew the cap on top of the roller, have a look inside, there is probably a cur-clip that you have to take off, then the whole roller and the bearings will come off the shaft. You then carefully knock the bearings out of the old roller and press them into the new one, then put the new roller on the same as you took the old one off.

Cheers
Alan.

I tried unscrewing the cap. It turned but it didn't unscrew and I'm afraid to try and force the stem out because I don't want to break it if that's no the way it comes off.


I don't know if you can see this but this is what the one I bought looks like.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=110727001607

It must just push through because there is no threading. I'm going to try calling the seller.... again. ... to see if he knows.
 
I am a bit befuddled about what you up against.
On my 440 C machines, the pinch roller (looks kinda like your ebay picture) just slides over the pinch roller arm shaft that is permanently attached to the arm, and then the aluminum cap screws on to the intenally threaded shaft . The roller has a bushing ( the brass sleeve shown in your picture)....there are no bearings, the the "stem" is part of the arm. The cap unscrews....yours might just be seized up

No clip to take off either...the cap is what hold the roller on
 
I am a bit befuddled about what you up against.
On my 440 C machines, the pinch roller (looks kinda like your ebay picture) just slides over the pinch roller arm shaft that is permanently attached to the arm, and then the aluminum cap screws on to the intenally threaded shaft . The roller has a bushing ( the brass sleeve shown in your picture)....there are no bearings, the the "stem" is part of the arm. The cap unscrews....yours might just be seized up

No clip to take off either...the cap is what hold the roller on

Possibly. The cap just spins around though. But the shaft on mine comes off the arm and the arm has an allen nut on it and you adjust the shaft height from there. I took some pics I'm going to put up.
 
Kind of a blurry picture but you can see how the stem is attached to my old pinch roller and the cover is on. Compared to the new one where there is no cover.

madadanniversary 021.jpg
madadanniversary 023.jpg
 
I spoke to the seller. He's been making these for decades. He said the cap is sometimes glued on and you can sometimes tap it out by using a rubber mallet on the stem. There are bearings in there. If I can't do this he said I could send it back with mine and he could do it.
 
Neither of the pinch rollers pictured in your last post have "bearings" but bushings as was mentioned above.

The factory roller cap is a friction fit piece with a rubber o-ring. I've usually used a knife blade to pry the cap off with some paper between the blade and the top of the roller to keep it from getting marred. If you work carefully and patiently I think this method works without damaging things.

Once the cap is off (as also mentioned above) there is an external circlip or "snap-ring" that prevents the roller from sliding off the shaft.

So you need to get the cap off your original roller (hopefully it is not glued...try heating it in the oven on "warm" for a bit to see if that helps to soften things up), and then you'll need some circlip or "snap-ring" pliers to get the clip off.

Hope this helps.
 
Hi Cory,


Thanks for the replies from all. Peck mentioned the same thing about removing the cover with a blade. So maybe that's what I'll try. I don't think it's glued because it turns. I think it's just popped in the groove. I'm still working out the slow take up issue and I'm waiting on some caps to come from mouser. So I may wait until I get things put back together. I want this back to 100% again!
 
Thanks for the help. The cap just popped right off in seconds. It doesn't even stay on the new one so I'll probably just use some mild glue. So no oil is needed?

I don't know what the seller was talking about, popping it off by hitting the stem with a rubber mallet??? :confused: That wouldn't have worked.
 
Hammer-mechanic. "He no fit I make-e-fit."

Is there a groove on the inside shoulder of that cap? If there is that's for a rubber o-ring. That creates a friction fit between the cap and the inside diameter of the idler roller.

Hey I've been following your posts on the Ampex List...can't say I totally follow what's going on or what troubleshooting you've done. I hope we can help you get it sorted out.
 
Hammer-mechanic. "He no fit I make-e-fit."

Is there a groove on the inside shoulder of that cap? If there is that's for a rubber o-ring. That creates a friction fit between the cap and the inside diameter of the idler roller.

aha! That makes sense. There is a groove but I have no O ring. Maybe I can find one at the hardware store.

Hey I've been following your posts on the Ampex List...can't say I totally follow what's going on or what troubleshooting you've done. I hope we can help you get it sorted out.


Thanks Cory. Is the post confusing? I guess what it comes down to now is the sliders on the resistors for the tension adjustment are slid all the way over to one side, and while checking tension on the reels with string and spring scale, the tension is barely strong enough to fall in spec. I know it's lost strength somewhere because it definitely had much wider play room before. I don't really know where to trouble shoot it though. Maybe I can start by checking between the resistors.
 
No, its not that the posts are confusing...I worded that poorly...I just con't formulate a clear picture of where to go.

Have you measured the voltage at the input of the resistors?
 
No, its not that the posts are confusing...I worded that poorly...I just con't formulate a clear picture of where to go.

Have you measured the voltage at the input of the resistors?

I haven't taken any voltage measurements. Sounds like a good place to start.
 
Back
Top