Problems with depth of cut and steps per mm.

Hi There,

Just put together the Lowrider (started printing it 6 months ago…)

Would firstly like to thank Ryan for all his hard work - It’s an amazing machine and been a real pleasure to print and assemble.

Secondly as a word of caution - I sourced my parts from AliExpress, thinking it would be cheaper and the shipping would be lower than getting something shipped from the states. I was horribly wrong and would never recommend it. There were items I didn’t receive and had to source locally, and finding everything was a bit of a struggle. For any would be builders I would definitely suggest sourcing your parts from this website.

I’ve done a few cuts but have also run into a few problems.


First Issue is still present, but doesn’t seem terribly troubling.
I’ve calibrated the X and Y axis, the X axis is sitting at about 200.83 steps per mm and the Y axis at 100.23mm

This seems a little odd to me and makes me think the RAMPS board I’m using isn’t picking up the jumpers to enable /32 stepping on the Y axis.

However, I’m getting pretty accurate dimensions, and I’m doubting my calipers before doubting the machine.


The second issue is however a little more troubling.

I was attempting to cut 1.5mm polycarbonate for some record blanks last night,

I’ve generated everything in Fusion360, in two processes; the first process is to mark the centre spindle holes using the drilling process and the second process is to cut the blank using the 2D Contour Process (I was hoping I could do it in one process with my 6.4mm router bit to route out the 7.2mm hole, but I’ve run into another problem with the tool being too big for Fusion 360 to work with)


In my first attempt the holes drilled themselves to 1.5mm as specified, however when I ran the second process it routed the outside of the blanks to a depth of 8.5mm despite being set at 1.5mm.

I thought I had made an error selecting the top height and bottom height, so I re-entered Fusion 360 and made sure that the top height and bottom height were marked to the top and bottom of the model.

On the second run the cut went through to a depth of 4.11mm.

I haven’t been eager to try cutting blanks again so I decided to test my Z Depth. I measured my Z-Depth by using calipers to measure the 10mm steps in the repetier firmware.

I measured from 27.59mm -> 37.75mm -> 47.58mm -> 57.63mm -> 67.71mm

Considering the calipers once again, I’m happy that the 10mm steps are accurate.

My next test was to cut a square within a square in 12mm plywood.

The model is a 100x100mm square, the outside edge cut to a depth of 10mm and the inside square(50x50mm) cut to 5mm.

For this I used the 2D Pocket function, feed speed of 480mm/minute, pass depth of 1mm.
In the Fusion 360 simulation this gives me 5x passes for the 50x50mm square and 10x passes for the outside which I’m fairly sure is correct.

However when I cut the square it cut both squares to a depth of 11mm.


Is this a Fusion 360 issue or a lowrider issue? I’m considering maybe the Z axis isn’t zeroing correctly.

In Fusion 360 I’m setting the origin to be the top of the lower right corner, when I go to cut the piece I am setting the tip of the router bit to the same place.


Thought I should note - I’m using MPCNC_Fusion360_v10_SDCard.cps

lowrider-100mm-square-test.gcode (136 KB)

Your welcome, thanks.


All bad both should be the same. The ramps shield probably has some solder issues. It is why I do not carry them any more.


As for your other issues, can you please try estlcam. I can not really diagnose fusion cam issues as there are more than 40 settings to go through per cut. No one can really help if you don’t know what is wrong. With estlcam you can send your file and we can very quickly see what is wrong. At the same time, you have to have your machine on point first.



ahh, that explains a bit.

re Fusion360 - I made a silly mistake, I set my origin to the top of the material not the top of the model.

I’ll check over the RAMPS board today.


Thanks again, once it’s done I’ll get some photos up in the build thread.