I think this is primarily due to the fact that I have some slop in my connection of the gantry rail to the truck. No matter how much I tighten that clamp I am able to get a decent amount of play in the gantry rail, enough to where my trucks can get off +/- 1/2". Is this expected behavior and I should move on or do I need to look into tweaking my prints so that I can tighten up this connection?
Ive read as many of the other topics on this issue as I could and it seems like there is some slop to be expected here I’m just not sure how dialed all of this needs to be.
With a stepper on each end, the slop across the axis is not a concern. Just be sure that the truck isn’t flopping around on the rail itself, and rolls freely.
Thanks for the response. That is kind of what I had gathered but it wasn’t explicitly clear in the instructions. So the thought process is that the steppers should drive both trucks at the same rate, so as long as you make sure they are squared up before you run (via endstops or some other method) then it shouldn’t get off in operation?
That’s how it works for me. My axis flops all over the place, but the steppers keep it nice and square. Be sure that you have the same very light tension on the belts. Too much on one side might bind-up the movement, and there will be fewer teeth if the belt is stretched. It seems to me that with unequal tension, the travel might be slightly different on each side.
I’ve found that this thing is as much an “art” as it is “science”. If you “just get it working”, I think you’ll find that the device is surprisingly accurate. The most important square-ups are the feet, and the height of the legs. The rest of it is very tolerant to slop. I gave mine no shortage of slop!
Auto squaring on a dual endstop setup will be able to measure that angle, and correct it. If you have the serial setup, then you can make some “hard stops” where you pull the gantry against something (like clamps) and then energize the motors. The motors will move in lock step after that.
Some movement is normal, they should remain square with the motors energized though.
On the Primo, you should adjust the trucks so that they “want to” be square when not under power. They should be able to be adjusted to that point, though you’ll still be able to move them some, when you aren’t trying to move them, they should square up. Gorilla tightening the clamps won’t stop them from moving, and might end up stressing parts that you won’t really want stressed.
