X1 mill column stiffening

[quantumeer]

Hello all.  This is a very appealing site; I hope this first contribution of mine might interest someone.  I was looking at the deflections of the column of my little X1 mill (Chester Cobra) the other day.  The figures in the photo show the backward deflections when a standard force is applied to the top.  The deflections are in 0.01 millimeters, when I pushed the top just enough to make the front of the machine base want to lift up.



Sure, some of that is just bending of the skinny column, but my impression was that it was not increasing as fast as you'd expect with height.  A graph confirmed a substantial linear component, leading me to think it is pivoting backwards at the base.



More to see if I was right than to turn the X1 into a Bridgeport, I decided to use the upper and lower column tilt clamp bolts to rigidify the column base.  Yes, the holes in the casting are slightly cockeyed, but never mind.



I used an extended lower bolt and a loose retaining plate at the bottom, and a substantial iron bar with bed iron supports at the top bolt.  These aren't in the way of anything important, and a preliminary bit of blue paint even suggests original equipment.



The result?  The green dots below.  44% reduction in movement, and the pivoting component has largely gone, as I hoped.



I don't know how much this improved rigidity buys me, but it somehow feels better, and this was pretty easy.  The retaining plate contributes nearly half the improvement; I guess removing the tilt mechanism and reinforcing the column would do better, but I think that would be overkill for this machine.

Mark

[Brass_Machine]

Hiya Mark!

1st, welcome to the collective

I know there is an article in Model Engineer Workshop that talks about stiffening the X1 column. I believe the guy also used a granite/epoxy fill in the column. It is issue 151... June 09.

Eric

[Captain Jerry]

Mark

I think you are right, much of the movement is in the pivot mount.  Harbor Freight (US) used to sell a version of the X1 without the column tilt.  The column is just bolted solid to the base.  The only way to tram the column is to use shims but done once and done forever.  I upgraded to the X2 with tilting column which never gets tilted and I think the X1 with the solid mount is stiffer.  I haven't modified the X2 to stiffen it yet.

Jerry

[ketanswali]

Hiya Mark!

1st, welcome to the collective

I know there is an article in Model Engineer Workshop that talks about stiffening the X1 column. I believe the guy also used a granite/epoxy fill in the column. It is issue 151... June 09.

Eric

I know about the idea. The granite/epoxy fill in the column should only be carried out by someone who has experience. In my opinion, it was a poor idea/method which was used. It probably did the job, but the machine was being pushed beyond the duty it was designed for. I have purchased the said machine off the writer of the article. Although I do not agree with many of the modifications he had made, as they were made with the view of pushing the machine beyond what it is designed for, we did sell and we continue to sell a lot of the SX1Ls, as a result of the articles published.
Ketan @ ARC.

[quantumeer]

Thanks for the comments.  By my reckoning, you'd struggle to get 20% better stiffness even by filling the column with iron; maybe 10% with epoxy/granite.  Perhaps it would help with vibrations, but the real solution for heavier work is an overall heavier mill.

I'm not unhappy with the little mill: over the last few years it has proved good value for money.  It is up to doing most of the things that I make, except things like tooling, where removing chunks of steel is too laborious.  I'd be interested in recommendations of a stouter mill with a small footprint - I don't need, and can't easily accommodate, a big table.

Mark

[HS93]

I have recently sold my X1 mill it was from Warco and gave exelent serviceI did a lot of chomping big chunks of ally and brass and it worked great , as long as you take it easy , it is a small machine, I did think of doing the epoxy fill if you look on some of the X1 CNC sites there is plenty of information on how people have stiffend the colum, the easy way is a bracket of the wall, but I think if you stiffen the colum the quill is not up to it and you will go on and on , eather mill slowley or get a bigger mill, have you gone for a belt drive as that was the best mod I did hear are some bits I Made to cnc mine and a mates machine
Peter

[quantumeer]

Interesting pictures, thanks.  When I get a bigger mill, I might CNC the X1.