Hi All,
Doing some more tuning and alignment and found the X axis is not square to Y axis rails. About 1/16" to 3/32" checking
about 16" + across. Important ? Not my Grandfathers framing square, machined all around on Fadal vertical machining center. Also, what syncs to two Y axis steppers ? Curious to how it works.
Really not trying to make a missile launcher out of this ! 
As always appreciate the help !
Brian
Thatās more out of square than weād like to see, but at the lower end is w/in tolerances for the extrusion cutting.
You can shim it, or best thing to do is remove the extrusions, take them to the Fadal vertical machining center and have them all machined square,
The two Y-axis steppers are driven by two different stepper drivers, but the circuitry on the board is set up so that they counter-rotate.
I bought a new square like yourās at HF and it was farther out of square than your machine. Iād suggest checking the square to verify it is true before you go to extents adjusting your machine. Just my opinion. Jude
Tighten your belts!!!
Mine was out 3/16ths out, tightened my belts (tight) now itās a thing of beauty.
HI,
Thanks for the reply. Iāve already machine the ends of the side rails as they were out of square. Made sure the were the exactly the same length also.
See a note below about belt tension.
Brian
Thanks ! Will look at that also.
Brian
Okay, if the extrusions are square and the same length for the Y-axis, then itās an uneven bend in the end plates ā figure out which is straightest, make that the one at the front, at the back, make sure if thereās a gap that itās on the left side (so that the homing switch contacts first reliably). If youāre inclined, put a pair of large crescent wrenches on where the extrusions attach and bend into being flat / square / plumb.
Hi,
" Not my Grandfathers framing square, machined all around on Fadal vertical machining center." It is square.
Appreciate the reply !
Brian
FWIW, in the future, rather than removing material from the square, you can square it up by hammering on the square at the angle, near inside corner to make obtuse, outside to make acute.
I will check on that tomorrow.
As always , I appreciate the help !
Brian
Very correct ! Most donāt know that. But, when I had my shop going and owned the Fadal I could not resist machining it !
Brian 
I have not done extensive testing with this, but what little investigation I have done is that squareness is relative. Itās easy to nudge one side or the other of the gantry (without power) such that it is out of square, and after jogging that āout of squarenessā is maintained. Now I understand there are a number of compounding variables here, but I wanted to convey what I had found during my calibration exercises.
Hi Jim,
Yes, found that to be true without power to motors. I also did a test under power and jogging to see how much the squareness changed. I would say it maintained the squareness I adjusted for. I suppose the sync between the y axis motors and belt tension plays a part.
It was so far off it was affecting the relation to the hold down holes in my base. Thatās how the whole squareness thing came about. Relative to the hole machine it is good enough now.
Brian
The machine endures a lot of stresses during a cut file with gantry moving and the router spinning and all the cutting forces, is there a concern that it can work itself out of square? Being a kit, i figure āseasonalā squareness checks are required because of that, but is there anything reasonable that could be added to the frame to strengthen the squareness of the machine? Reasonable refers to non-machinist applications (I guess). Thanks
Hi Jude,
Being new to this machine I think keeping the fasteners tight and looks like belt tension checks would be good.
From my experience so far I think it is pretty solid being a kit. Iāve gotten better at knowing when to stop fussing with something. It is what it is. There is only so much thatās reasonable to try and make into something beyond its design.
Till I know more I tend to keep feed rates probably slower than I should. May give the machine less stress ?
Brian
Babying a cut doesnāt help as much as one would wish ā the endmill rubs, galls, and overheats and doesnāt cut as well There are a couple of articles on this at CNC Cookbook.
