Squeezer tolerances/compatibility

[MattChaloner]

Hi All,

Hoping this is the correct sub forum to post this in.

I was wondering if anyone has had any experience of squeezer yokes fouling on their pneumatic squeezer?

A while ago I bought a pneumatic squeezer of the 214C variety. It didn’t come with an adjustable ram, so I purchased that separately. I found it difficult to fit, but with some filing I managed to persuade it in - although it’s always been “draggy” on the return.

I’ve now just got a longer yoke, because the standard one that came with it wasn’t much use. Having tried to fit it, the holes don’t seem to quite align for the bolts to go in. I can drift them in with a punch and a hammer, but it’s so tight that it seems to put tension on the ram which then won’t extend. To get the yoke back off, I have to again drift out the bolts holding the yoke to the frame.

This doesn’t seem quite right and I was wondering if anyone else has had a similar experience, and if I’m likely to cause other problems if I start filing away at the body of the yoke, or the yoke pin holes, in order to try to make it fit better?

Thanks in advance
Matt

 

[HFS]

Some "precision" is being lost somewhere, i.e. squeezer, yoke or adjustable ram tolerances. Properly made, all the mating pieces should go together smoothly, with no undue "force" needing to be applied. Have you tried the assembly with the original fixed ram as supplied?

I see you are in the UK - any chance metric dimensionality is at work here?

HFS

 

[MattChaloner]

Some "precision" is being lost somewhere, i.e. squeezer, yoke or adjustable ram tolerances. Properly made, all the mating pieces should go together smoothly, with no undue "force" needing to be applied. Have you tried the assembly with the original fixed ram as supplied?

I see you are in the UK - any chance metric dimensionality is at work here?

HFS

I haven’t tried the original ram, but it’s a good idea and I’ll give it a shot.

The tool is from the US, USATCO brand, and the ram and yoke both came from a UK-based stockist who import the items from the US so I don’t think it’s because of metric dimensions.

If the original ram works, could I be looking at a slightly out of tolerance ram in need of replacement?

 

[D-Dubya]

If it don't fit, don't force it! You may have exacerbated the problem by whacking it with a hammer. Is there any chance a slight burr formed on either the yoke or the ram? Also, you didn't say, but are you applying a thin film of lubricant to it?

As far as the bolts going in, mine occasionally just won't push in (they're the tractor pin type). All I have to do is take the yoke & ram back off, then try it again. I've never figured out what's different, but it goes back together fine after that. Something is just barely out of alignment I guess. I've had this squeezer for over twenty years and it was used when I got it. Still works fine.

 

[HFS]

You might also check the bore of the yoke you are using with a precision micrometer - should be in the .376 - .378" range. Also check the diameter of the adjustable ram sleeve - should be around .370 - .372" range. Typically a couple of "thou" clearance is needed to make everything work right.

Also, the "squareness" of the ram bore to the two yoke mounting holes ...

Thanks - HFS

 

[Ironflight]

After twenty years and multiple airplanes, my adjustable ram got kind of tight - I imagined it was because it grew in diameter with all those forces on the end. I chucked it up in the lathe and just kissed it a little, and it smoothed right out. I’d second the suggestion that there might be a little burr or mushrooming going on.