935TS knee issue. Not Happy

litewings

H-M Supporter - Silver Member
H-M Supporter - Silver Member
Joined
Dec 23, 2019
Messages
122
Started the install of the Z axis power feed and ran into this issue. One hole of the bearing retainer is broken out. Upon inspection, It appears all three holes are drilled out of position outward from center on the knee.
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The replacement retainer that the drive mounts to does not align with the holes drilled in the knee. A posible work around may be to mill the retainer holes outward. There is not a lot of edge distance to work with here. Curious if anyone else has had an issue like this? If so, what was your fix? I hope I didn't get a Monday morning hangover built machine. Not off to a good start.
 
I think I would be tempted to re-clock the removable elements ~30-degrees clockwise, transfer punch the bolt positions using the inner bearing housing as the marking guide, and then re-drill and tap the casting at the new positions. But first I’d put a call into PM. I have posted my Align feeder install log for my 935 here for reference. I did not encounter the issue you have.
 
I think I would be tempted to re-clock the removable elements ~30-degrees clockwise, transfer punch the bolt positions using the inner bearing housing as the marking guide, and then re-drill and tap the casting at the new positions. But first I’d put a call into PM. I have posted my Align feeder install log for my 935 here for reference. I did not encounter the issue you have.
I have thought about re-clocking and drilling also. I think either could work. I'm really having bad flashbacks of a Chinese built POS I had years ago. I'm not in a good mood having to do repairs to a new machine that's supposed to be superior quality. I paid the premium for a Taiwan built machine to avoid this.
Waiting to see what PM has for a solution.
 
I have thought about re-clocking and drilling also. I think either could work. I'm really having bad flashbacks of a Chinese built POS I had years ago. I'm not in a good mood having to do repairs to a new machine that's supposed to be superior quality. I paid the premium for a Taiwan built machine to avoid this.
Waiting to see what PM has for a solution.

Oh Man, That's a bummer! I agree with your statement about spending premium to avoid that kind of problem.

Tim
 
I had a similar problem on the X axis on my mill. My fix was to replace the cast iron part
by machining a new part out of steel. It's been fine now for quite a few years.
 
@litewings Did you get this resolved? I'm curious what PM told you.
 
Well, not repaired or resolved as of yet. I will give an update when it is.
 
The repair is done. I ended up clocking the retainer counter clockwise and drilling new holes in the knee casting. I used the standard attaching holes in the new bearing retainer for the power drive which leaves it hanging closer to the 6 oclock position instead of the standard 8 oclock. I don't, at this point intend on installing a Y axis power feed so should be OK. If I do upgrade, I have room to drill and tap mounting holes to the standard clocking on the bearing retainer if clearance is a problem. I used the power feed retainer as a template and built a drill guide to prevent off center holes like I already had. Worked out well. But still not happy about having to do this to a new machine.
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Glad you got it fixed. Not sure why you went CCW instead of CW, but at least it's resolved for now. I really like having a Y-axis feeder for squaring up stock.
 
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