Calibrating and Squaring

I’ve made some changes to my Lowrider (I’ll update my build thread in a bit), so I’m going to need to re-square it, and I’m interested to hear how others might approach this.

I use the Y belt holders as hard stops against the Z tubes as my starting point. To check for square I:

  • First put my sharpest V bit in the router.

  • Then jog over about 10mm in both X and Y just to ensure being hard up against the stops doesn’t affect my measurements, do a “G92 X0 Y0” and then jog the Z down to make a tiny divot.

  • Next I raise the Z back up and move about as far is I can in X (say 2 meters) G0 X2000, jog down the Z to make another tiny divot, and raise the Z back up.

  • Then move about as far over in Y as I can (say 1 meter) G0 Y1000, and make another divot.

  • Finally, move X back to zero, G0 X0, and make one more divot.

  • Using a scrap stick of appropriate length, I tapped a pin nail into the stick, so the point protrudes just a tiny bit

  • Setting the pin nail in one of my divots, I marked the middle of the diagonal divot with a marking knife

  • Then checked this against the opposite diagonal in a similar manner.

  • Finally, shim one of the Y belt holder / hard stops with masking tape as necessary, and repeat until square.

I hope that all makes sense. 8^)

I think I had my Lowrider pretty darn square using this technique. I used a similar approach to verify that a 600mm move in X and one in Y both moved the same distance.

The only tools I have to measure Lowrider scale parts are a tape measure and an old wooden yardstick. I have no faith in the accuracy of either, so I haven’t tried to “calibrate” my Lowrider.

If anyone has thoughts regarding a better (or just alternate) approach to squaring or calibrating, I’d love to hear it.

I’m thinking of picking up a longish (~48") stainless ruler with both inch and metric markings, to check calibration, but haven’t committed yet.


That sounds like a pretty good method to me. You don’t need anything fancy to get good and square.

1 Like

Thanks Jaime,

No you don’t. It seemed like a good method to me, but there are much brighter minds than mine on this forum (yours among them, I’m pretty sure), who might have another approach.

There’s not much in the docs on squaring a Lowrider, so I figured it wouldn’t hurt to ask.

It definitely seems like it would work fine, as long as it was done right. How would you make sure you had the right dimple on the second and third attempts at measuring it? I suppose you could put down a piece of tape, and replace it after each attempt.

A piece of tape would work.

I was making tiny dimples. Like 1mm diameter. So they’re hard to find even just after you make them. I was using a pencil to circle and number them (1 for first iteration, 2 for second etc.) as I made them.


I just did this last night, again. I use a pen and the lcd to manually jog to each corner and draw a little corner. I did make some gcode but it doesn’t work for some reason. I go a little bigger with each try to get fresh corner lines

I then use pieces of blue table on the hard stop to shim it square.

1 Like

When you say “draw a little corner” do you mean that you draw an “L” shape (appropriately rotated for each corner, of course)?

Also, my build is 56in x 111in (1422mm x 2819mm) but would it be okay to do this calibration at the corners of a 48in x 96in (1219mm x2438mm) rectangle or would that leave too much room for innumeracy? Thanks!

Just draw a square with the machine and measure the diagonals.

I got fancy and just drew the corners of the large square. You are just looking for the corner points to measure.

1 Like

Thanks! I built my original build a few months back but over time my terrible table build became a problem so I’ve built a sturdier table with a few mods I printed from Thingiverse. Just wanted to make sure I avoid having further issues in the future as a result of my ignorance haha.