Z axis is shallow and holey calibration is grayed out on web control


I’m new to the community. I’ve gone through and gotten a lot of information from the forums that I appreciate you veterans mapping out.

There are a few things in struggling with and curious about.

  1. My z axis is very accurate when self controlled in web control. But when I try to run g code, it’s very shallow of the depth commands in my cad designs. Holes that should be through 3/8" material are about an 1/8" shy. I’m wondering if it has anything to do with the instructions on metal Maslow (where I purchased the kit) to:

“… Since our motor is faster than the original please use the following settings:
4200 encoder and 14 pitch (assuming 2mm pitch, if 8mm then it would be 56pitch)
Other people have made it go even faster by multiplying by 10 so
6000 encoder and 20mm pitch”

I tried changing those settings and web control gave me a bunch of warnings and wouldn’t work. Instead, I changed the pitch of the z axis in the settings with a bunch of trial and error with a caliper until I hit 25.1 which is very accurate. But the cad depths are all shallow. I’m wondering if it’s due to those settings.

  1. Holey calibration is grayed out. I couldn’t get the firm ware to work. Is it significantly better than the triangulation calibration? Is optical worth the trouble as well? I couldn’t find good optical instructions.

These are just a few of my main questions if anyone might be able to help.

Many thanks to y’all for all the good info.

Holey is better than traditional but requires a firmware update. You will need to get the 0.95 prerelease if you want to update your firmware. Optical isn’t well known. I know of one person who used it and they are the one that wrote it. I disabled it in the newer version of webcontrol I’m working on.

The higher rpm z motor needs new pid values to function properly though that may be a function of the shield being used. Tuning the pid can also be done from the webcontrol menu.


Thank you. I’ll give those a shot. I’ll report back after attempting.

Darth, are you having the same issue as I, were the z axis gcode and sled values shown on webcontrol are different?

Tim, I’m not sure. I’ll double check when I get back into the shop this week. In that screen shot, you are drawing my attention to the g code z being -11.43 and the sled being -11.32, correct?

Correct and it seems like I get some unevenness in my pockets, possibly connected? I don’t know.

you need to change the advanced settings value from the default 7560
z axis encoder steps per revolution =7560.0

to one of the following:
4800 encoder and 16 pitch or
5400 encoder and 18 pitch
6000 encoder and 20 pitch.

bigger the number the faster it goes.
both encoder and pitch must be changed together.
I do not recommend going faster than 6000 encoder and 20 pitch though some have.

speeding up the z motor is the biggest speed upgrade that makes the machine go faster, especially if the piece you are cutting has a lot of pocket cuts.

which is why we use a much faster and stronger z axis. added benefit is that the wire connector is bigger and doesnt’ tend to fall out, the original cable getting loose was a major problme for many people

note for clarification, these are hardware changes (the motor changes to change
the encoder steps, and the screw changes for the pitch)

you can’t just speed up the machine by changing these settings in softwae :slight_smile:

David Lang