We have an extremely early run 1100 at our Makerspace. We’ve had it for years. We got it used well before I became a member. None of our members have been any help with this.
I am no noob to machines. I’ve worked in die shops and have previously had my own manual mill. I realized the 1100’s spindle was out of tram recently, so another member and I dealt with that yesterday, levelling it first. I don’t have a level to get it to half an arcminute, but we did get it to 1-1.5. No measurable twist to the base casting following the squaring procedure. At least not more than the resolution of my level, 1-1.5 arcminute.
It’s trammed to less than half a thou on a 6.4" circle.
After tramming, a test indicator on the left and right side of a large 123 block showed that the Z axis is rotated to the right about the Y axis about 1 thou per inch, and towards the back of the machine by 1 thou per inch.
I have also measured a repeating half thou surface wave in the Z direction on radius when using it as an inverted vertical spindle lathe, suggesting movement related to the ballscrew, maybe?
I intend to follow the GIB adjustment procedure next time I have the time near the machine, and check the… free play? I think it was called in the procedures.
What are the chances it’s loose GIB[s] vs an out of square column? Or, there’s base twist I can’t measure with my level?
I vaguely remember some issues with the very early 1100s that needed shimming or scraping of paint drips, but its entirely possible the machine has been crashed too. Makerspace machines often get banged around.
Step 1. Figure out what tolerance you need.
Step 2. Figure out how much money you can spend to get the equipment to get to that tolerance.
Step 3 re evaluate step 1 until step 2 fits.
Step 4. Commence machine adjustment.
Start with the gibs.
Any slop there throws everything out.
Put an indicator on the spindle and push pull.
You’d be surprised at how much it moves. Tighten the gib while watching for lost motion while jogging in .001". Find a happy medium.
Go back and take measurements.
I bought two 2-4-6 blocks from Amazon for
$74 Mic’d them and checked them on a granite table w/ 10ths indicator. Really pretty good.
Left right lean was .0004 over 6".
Nod was .0014".
So nod is .00023" per inch.
I already shimmed the column when I assembled the mill. Not sure I want to go back in again. Get a chip in there and chase my tail.
I could try to snug up the Z gib a touch more. 770MX
It’s really important to isolate down exactly where the alignment issue is. It’s also very difficult. Make sure your spindle bolts are tight too. That’s where I put my shim. You can do x and y with one, sometimes.
There’s a hundred ways to chase it down but sometimes the chasing just makes it worse
Having thought more, I’m going to start right from the beginning, mapping the “flatness” of the table, then checking/adjust the ball screw freeplay, ballnut freeplay and the gibs for each axis, starting with the Y, then X and then Z.
We shimmed the spindle. One shim to take care of X and Y.
My 1100 dates from 2006 so it’s also amongst the earliest ones in the series. I also had issues with tram and, at the time. Tormach told me that the mills had been setup at the factory on a heavy steel table for alignment and adjustment before they were transferred to the Tormach base and that the mounting points (flats on the base) at the time were just rough machined and not guranteed to be co-planar. Consequently, when the mill body was bolted down to the base some twist could be imposed on the ways and table. Tormach recommended that I loosen the (4) mounting bolts between the mill and cabinet and shim so as to minimize the tram in the table about the X and Y axes. At least that is what I remember at the time - I could have some details wrong.
I did as prescribed and was able to shim enough to get the tram about a 6-8" circle in X and Y down to about 0.001" overall and called that good enough. Kept meaning to do that again over the years but never got around to it. I do know that a flycutter traversed across the table from right to left cuts a little on the trailing edge so I still have some tilt in the column or about Y.
Harold