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1966ish Deckel FP2, endplay in Y-axis handwheel

sigurasg

Aluminum
Joined
May 4, 2018
Hey y'all,

My FP2 is the external motor version, 400mm X travel, serial #5415. This is 1966 vintage, according to FS.

At some point I noticed that there's a bit of a "clunk" in my Y-axis handwheel sometimes, perhaps when I switch from power feed to hand feed and/or reverse hand feed direction.
On investigation I found there's a bit of endplay on the Y-axis shaft from the handwheel to the bevel gear (I assume that's where it goes). I've been trying to figure out what the bearing arrangement there is like and how to get into it. The parts manual I have doesn't really have a good breakdown of this that I find, though maybe I'm overlooking it - it's happened before :).
I assume there is a pair of thrust bearings there with a nut and a locknut, like e.g. on the X-axis handwheel. I did a search on the forum, but I can't find any good images or descriptions, alas.
Can anyone point me in the right direction?

Siggi
 
On the Y axis the spindle is stationary and the nut turns
So there are thrustbearings on both sides of the nut
If you remove the bellow you see a flange with some setscrews
With these setscrews you can adjust the thrustbearings
peter
 
On the Y axis the spindle is stationary and the nut turns
So there are thrustbearings on both sides of the nut
If you remove the bellow you see a flange with some setscrews
With these setscrews you can adjust the thrustbearings
Hey Peter,

Thanks, that's good to know, but I'm talking about endplay in the handwheel itself, e.g. I can push and pull the handwheel in and out a fraction - maybe a tenth of a millimeter (~4-5 thou) or so.
Presumably this is pulling a bevel gear in and out of mesh, which adds a bit to the backlash of the Y-axis.

Looking through my manual, I find it has instructions for getting the handwheel out. Seems the head has to come off first, so perhaps the adjustments for the handwheel's presumed thrust bearings are in there. I'm still not finding any description or depiction of that bearing arrangement or the adjustment.
I need to remove the ram to take a look at what sort of mess is inside anyway, so I guess I should just take a look-see in there.

Siggi
 
This is how it works on my 1964 FP2 (500mm-X-travel, motor in base):

attachment.php


You can remove the shaft by driving out the taper pin which retains the bevel gear, visible in the top drawing above. My recollection of this is that there are some thin shim washers (15mm ID, 28mm OD) which preload the 51102 thrust bearing. If I were in your shoes, I would get a replacement thrust bearing and a handful of thin shim washers before taking that apart, so it's not out of service for very long.

Here it is, "in situ" in my machine:

attachment.php


and here it is removed:

attachment.php


If you look closely, you'll see that the bevel gears are in poor shape, I think the Y had been crashed or the machine fell on its back in the past. I stoned these six years ago and they have worked well every since, so it's one of those things that I just live with.

The end play is set on the operator side with the hard steel thrust washer that bear against the bronze bushings that carry the shaft and on the gear end by the thrust bearing. You can modify the end play by adding thin spacer shim washers as described above. If you want the gears to mesh more tightly, add the shim at the top end in between the thrust bearing and the machine body. If you want to preserve the gear mesh, add the shim below the hard steel thrust washer on the operator end.
 
The end play is set on the operator side with the hard steel thrust washer that bear against the bronze bushings that carry the shaft and on the gear end by the thrust bearing. You can modify the end play by adding thin spacer shim washers as described above. If you want the gears to mesh more tightly, add the shim at the top end in between the thrust bearing and the machine body. If you want to preserve the gear mesh, add the shim below the hard steel thrust washer on the operator end.

Thanks, that clears it up nicely, and this matches up with the instructions in my manual. Another reason for pulling the ram off.
I guess the play I’m seeing can be explained by wear on the thrust washer or the bushing it bears against. Even though it looks like my mill was in a tooling shop in a research facility, or some such, the wear is going to accumulate over time.

I’m also realizing that the X axis dual thrust bearing arrangement is primarily for the lead screw, it just so happens that the hand wheel is directly on the screw.
 
If you look closely, you'll see that the bevel gears are in poor shape, I think the Y had been crashed or the machine fell on its back in the past.

I have trouble imagining how these gears would get chewed up with use, as they don't transmit any force to mention. The only force on there is what the user can impart on that little hand wheel?
Maybe they ran so far out mesh that the tops of the gear teeth were effectively skipping?

When I first got my FP2 I ran the motor in reverse (like an idiot) and I drove the ram into a hard stop forward, as of course the power feed stops only work when the motor runs the right way. This wedged the Y axis pretty good. I was able to get it moving by the handwheel, though I had to use a spanner on the handwheel nut. The handwheel on my mill isn't keyed to the shaft, which reinforces my belief that it's not intended to transmit any force to mention.
 
I have trouble imagining how these gears would get chewed up with use, as they don't transmit any force to mention. The only force on there is what the user can impart on that little hand wheel?

Some of the abuse that my FP2 endured before I got it is documented here:
https://www.practicalmachinist.com/...ce-help-my-new-deckel-fp2-build-1965-a-275599

The crash or fall drove the Y-axis lead-screw nut backwards where it expanded into a steel bushing and also cracked the rear thrust bearing "washer" behind the nut. I think the forces acting on the nut, or the nut itself, must have pushed the two bevel gears together, because a handful of teeth are badly chipped.
 
Perhaps, probably even the machine was taken apart before and they had a few shims left after the fact :D
Make sure you have a good sturdy tool to get the tapered pin out And carefully look for the smallest end
A single wack should get it out (if you are lucky)

Peter
 
The crash or fall drove the Y-axis lead-screw nut backwards where it expanded into a steel bushing and also cracked the rear thrust bearing "washer" behind the nut. I think the forces acting on the nut, or the nut itself, must have pushed the two bevel gears together, because a handful of teeth are badly chipped.

Ah, that makes sense, and I do remember reading through your thread after I got my mill and joined this forum. Maybe the detritus from the breakage then damaged other teeth.

I was wondering whether it would have been possible for the Y-axis lead nut and its bevel gear to move forward in the machine, thus pulling the gears away from mesh. Looking at this image, however,
94562d1387694005-advice-help-my-new-deckel-fp2-build-1965-a-img_1879.jpg

it appears that there's a thrust bearing on the forward side of the nut, bearing against the casting?
 








 
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