Squaring the gantry

[bradbergemann]

Hi guys. Been working on some pistol grips and having problems with machining both sides of the panels. My gantry must be a little out of square, and when i flip the model over, the distance doubles and is not good. I could offset the drawing, but i'll have to do that for every model that has dual sided machining. I would rather get it right now, then have to go through all of that extra tweaking. I could use some help if you have the time. Thanks in advance!

[mecanicu]

Tell us you'r cnc model and describe you'r problem with more details.....if i cand i will help you.!!!

[bradbergemann]

i have a model 1325. i'll try to upload some photos of the problems this week. thanks again for the help.

[Big S]

I was going to do a tutorial on how to sort that out, never got around to it in the end.

There are 8 small allen head cap screws that hold the gantry onto the linear rail blocks. You can loosen these and reposition one side of the gantry to square it up, when the bolts are tightened it holds the gantry square. It can however be knocked out a little if the machine is crashed or isn't square when started up. This is due to the stepper motors being able to hold position.

I adjusted my hard stops so that If I manually pull the gantry onto them it is started up square. I don't always do this as it seems to stay square anyway. If the job is critical I will pull the gantry to the stops before starting just to make sure.

Let me know if you need any more info.

Shannon.

[bradbergemann]

Thanks Shannon! As soon as i get through with left over turkey from thanksgiving, I'll square things up.

[bradbergemann]

took a few measurements last night, and as rookie as this sounds, i don't know if the table top is out of square, or if the gantry is out of square, or if it matters which one i work on first. From the home position (front left front corner for me) when the gantry travels in full x+, it moves 1.1 mm in y+ relative to the edge of the table. From the home position when the gantry moves in the y+ direction 48 inches it moves 1 mm in the x+ direction. on paper, that's not giving me a full 90 degree angle. I'll measure the table tonight to see which one is right, the table or the gantry, or neither.

I checked the mechanical stops and they were uneven. however, they are not adjustable (slotted). i removed one completely, and found that the gantry would pull slightly back further on that side, but the rail bearings would only pull it back into position. in other words, without loosening the bearings, it is as far as it will go. to loosen the bearings, i'll have to remove the spoil material, and the first and last aluminum channels, unless you guys have a better idea.

thanks again for listening in.

[Eclipze]

I remembered you were questioning how squared up your table was and thought you might be interested in what a couple of mates and I went through last night. See post #15.
Excitech CNC Modifications Thread...

Hope it helps.