Column stiffeners and question about column to table perpendicular tramming

[Espeefan]

Hi guys,

I am in the process of going through the set-up of my new mini-mill - a Little Machine Shop Hi Torque mill, which is basically a Sieg SX2 clone. I have been reading a lot of threads, which talk about stiffening the column. I noticed right away that I could easily flex my mill's column about .005". I've already learned about the tramming nightmares, and I've worked my way through that. My spindle is now parallel (as best I can get it - it's still off about .003 to .005") to the column in the x and y axis, so my last job is to get the column perpendicular to the table. Naturally I want to stiffen the column too, and I've seen some interesting solutions on this forum. Now my question is, can I design and build a stiffener to adjust (pull) the column into alignment, rather then try to shim things? Have any of you noticed any downside to pulling the column into alignment in this manner?

One of my ideas was to actually build a stiffener, like many of you have, bolt it to the backside of the column, and then use jack bolts to push, or bolts threaded into the saddle, to pull the column into position. Another ideas was to build something more like an angle plate, with jack bolts pushing against my table top. My table is a purpose built, heavy, welded square tube frame bench. I am not to worried about it flexing with time. One of my last ideas was to employ a turnbuckle system, with clevises, attached to my column stifferner, and the bench, to pull the column back into alignment. Or possibily some combination of these ideas.

What are your thoughts? Just looking to see what you guys think. Thanks!

 

[Bill S]

If your pulling point is near the top then you might put a slight curve in the column. If that was the case then the front to rear tram would vary depending on whether you had the head down low or up at the top. It would be interesting to see what the difference was by temping up a brace with clamps and check the tram in various positions. Another point is how would the brace work when tilting the column. With my X2 I eliminated the column tilt.

Bill

 

[Espeefan]

Good point, Bill! I had thought about that too. I figured I would put a turnbuckle, mid-height, on the column and pull it/brace it, to the bench, but I think it would be best near the bottom of the column. With the motor drive at the top of the column, there really isn't a good place to attach a clevis high up anyway. Thanks for the reply.

 

[Rickl]

I've just finished putting a piece of 100 x 50mm channel in the rear of the column as described by other members. Really pleased with the result. X axis is +/0.01mm and the Y axis +/-0.02mm. Doesn't matter how much I fiddle with it that is it. I've eliminated the tilt facility.

Rick
Sth Australia

 

[lee9966]

On my Taig mill the column is plenty stiff, but tramming is a pain in the neck. I have been thinking about a turnbuckle between the side of the column and the bench. It would just be used to allow a more precise adjustment before tightening the column.

You have inspired me to give it a try!

Lee