Rf31 Won't Tram

[sk1nner]

I have an enco round column mill drill. I'm Trying to tram the head to the table. I was able to get the "nod" with in a thou. But the "tilt" just will not get any where need close enough to be usefull. I have some .005-.006 shim stock that I am using. I have my indicator mounted in the quill.

Before shimming.



This is after shimming.



I put 2 shims in to equal about .012. It only moves it about .0005. I know the small shims like I'm using aren't the best but they should at least move the head more than half a thou. Any suggestions to get this trammed? As always thanks for any and all help.

 

[hman]

You might find some good info in this article by Rick Sparber:
http://rick.sparber.org/TM.pdf
Apparently there are lots of factors in play, including small shifts (stress relief?) over time, non-uniformity of the head-to-column angle (especially along the column), etc.

 

[sk1nner]

Thanks for the article. What I don't understand is why am I not getting any change? I had about .025 in there at one time and it still didn't move it more than .004 or so. If for some reason I can not get it to tram I've thought about fly cutting, or face milling the whole table. I know this will present it's own challanges but does that sound like a viable option?

 

[RJSakowski]

Thanks for the article. What I don't understand is why am I not getting any change? I had about .025 in there at one time and it still didn't move it more than .004 or so. If for some reason I can not get it to tram I've thought about fly cutting, or face milling the whole table. I know this will present it's own challanges but does that sound like a viable option?

Is it possible that you already have a shim in place and your relatively small shims are going along side it?

An out of tram condition will not be improved by facing the table. The head is cutting on a slight angle when it is out of tram but it will not be changing its height as you move the table under it.

You wouldn't want to face the table anyway. The table surface has to be parallel to the plane described by the intersection of the x and y axes which is determined by the ways. Otherwise, you will cut tapers.

Bob

 

[sk1nner]

Your absolutely right, I didn't process the cutting wouldn't work, my mistake. Thank you for that. No, there aren't any forgotten shims in there. Before I used the tiny shims I have cut I was using pieces about 4 inches long, I cut those up to double them up and get the .025 I mentioned earlier. The "nod" was no problem (.005 got it with in .001), I just can't figure out the "tilt".

 

[T Bredehoft]

Wild suggestion. I looked at your pictures,s it struck me that perhaps you should shim the entire side, not just little strips. No logic, but it's what I would do.

 

[sk1nner]

I tried that, still didn't seem to do much.

 

[markknx]

Are you shimming at 3 or 4 points? you should only have shims at 3 points in this case. 1 corner should stay flat on the base. If you have shims in 2 places on the front and 2 places on the side then one set of shims at the adjoining corner will not be in contact with flange. Say you need .005 to tilt the head back and the you need to move the right side .004 then you need .009 on the front of the right side, and .004 on the right rear and .005 on the front left.

As mentioned in Ricks article some issues come up as you move the head on some of these machines. I own a round column mill.
Mark

 

[sk1nner]

I only had shims on 3 corners. I overlapped 2 sides shims when I used longer pieces of shim stock, I'm going to grab more shim stock at work tomorrow and give this another go. I will take pics of everything I do. I'm just baffled that it doesn't even seem to care how much shim I put in, it just doesn't move. I did learn the torque spec of those bolts on that article. That is one thing I will be trying with the new shims I make.

 

[David VanNorman]

I don't know your machine but do you have a head that will tilt? Try mounting a good angle plate on the bed and running the quill up and down to check that way. you might also find a way to get your indicator more solid.