What techniques do folks use to make sure that their X-Carve is squared up on energizing the steppers?
I find it too easy to find that I have turned on my X-Controller and found that my Y Axis is racked. @PhilJohnson talked in a post about using spacers, but since I have 1000mm machine, I can’t envision how I would hold two spacers and turn on my X-Controller !
It all depends on what your goal is as to the best method.
Are you looking for dead-on squareness or are you looking for repeatability?
If it’s dead-on, you need a perfectly square machine with accurate spacers and exact belt tension and Vwheel pressure on both sides.
My biggest issue was power cycle to power cycle squareness (repeatability). I had some spindle mount holes go slightly off plane due to this among other things.
What I did was created a jig. It’s 2 pieces of left-over 20x20 extrusions from the sideboard and then I used a longer 20x20 piece with the corner gussets and tied them together.
I put that on the top every time and pull the gantry square then turn on the machine. By doing this, I know the “square” is the same every time and so I can easily do half a carve, stop for a day or so, and then come back and as long as my material didn’t move, I’m good.
I made a clamping fixture for some same-sized signs I was making. I squared the machine using my contraption, squared the fixture to the axis and then left it in place. Over the course of a month I carved 50+ signs and all I had to do was use my contraption to square the axis and they were all the same across the length of the board.
EDIT Found an old picture of my “jig” I posted in a different thread…ignore the mess.:
Ultimately the best solution is a controller that treats each side of Y as separate axis for homing. i.e. LinuxCNC/MachineKit or Mach3/4. With-in both of them you can change the kinematics so that there are separate, but linked. So when Y gets home each stepper/driver combo homes at the same time but will only stop for the configured end-stop. I would use the edge of something of a good/known dimension to initially place the end-stops so that they are at the same distance from the end on each side.
I’m trying to square up my xcarve as well. I’ve made spacing blocks to use at start up. When I pull the left rail against the block it stays in place but when I pull the right rail to the block and let go, it pulls away about a quarter inch like there’s tension although I don’t know where the tension is. I’ve uploaded a video that shows the pull away: https://youtu.be/05Q5hJVn5Oc
Most likely the ends of your X axis beam are not cut square, and the Y carriage is under stress/strain when you pull it to the block. I had to use shims on mine to get the Y axis plates square to the beam.
I have two different methods that I use after power-up. I used to do the first before power-up, but then discovered that upon start the unit was out of square.
First is a jig, like the suggest of many here. But the gig I use mounts to the front rail of the system and clamps to the waste-board. I mount the jig and carefully and slowly run the gantry into the jig. If one side of the Y is out, one side will contact the jig first, and then the other side will contact.
I then tram the system on the X - following a carefully drawing line on the waste-board to see if the unit is still in square. I do this between operations, as I have found that in use the two sides of the Y can get out of true.
Remember, the X-Carve uses an open loop stepper system. Chips, dust, and other gunk can cause the pulley to slip a tooth and send either the X or the Y out of step. When the Y goes out of step the gantry goes out of square, but when the X skips, the dimensional accuracy goes out the window. The X can skip if the cutting speed is aggressive, the material is hard, or if the tool/bit breaks.