Easel & T8 Mini CNC Question

Using Easel with CNC Arduino Shield V3 and none of the cuts are coming out. The spindel moves to random positions and have no clue where to go from there.

Posted some pictures with this post. Any help would be greatly appreciated.

Thank you ,
John S.

Sounds like your grbl settings are wrong. How did you go about setting your machine up? hopefully not with easel

Used the firmware (GRBL 0.9j) that was provided by the vendor of the machine. I set on it was the steps to 1600 and inverted axis movement.

Should I upgrade the firmware ?

Post your $$ grbl settings

My current GRBL settings:

Yeah, judging by this you went through the easel setup and erased the settings for your machine and replaced them with the x-carves settings. you need to re program your card with the original settings the company gave you for the machine. Mostly it’s your steps 100-103 that are the biggest issue

You are loosing steps most likely.

  • Have you calibrated the steps per millimeter travel?
  • Have you calibrated the reference voltage of your driver to set the current limit to the steppers?
  • What microstep value have you jumped the stepper drivers to? Start with 1/4step (quarter step)
    The higher micro step, the less available torque is available at speed

@HaldorLonningdal I re-flashed the firmware, calibrated the steps and adjusted the current to 1.5A from 1.25A. Still getting really bad results when running easel projects. I will try to mess with micro-steps next.

FWIW - if the Arduino is acting “crazy” and incoherent it is usually a clone board, not genuine.
If nothing seen to fix the issue a genuine board may be the way to go.

Have you tried the same design sent through say UGS?

I have tried setting up the board with 1/8 step and re-calibrated. I am using an official Arduino board but the CNC shield is a clone. Results are still really off. Posted picture of machine running happy face project at a feed rate of 200.

Machine just goes to random positions.

@HaldorLonningdal Should I invest in better CNC shield ? I have built a lot of 3D printers. .this is my first CNC machine. . not sure what to do next.

Could you shot a video and post that, showing the carve process?
That might shed more light on what may be your problem.

1 Like

One thing that comes to mind from looking at your machine, the spindle is tiny What speeds and feeds are you using? You may just be going to deep and to fast for that machine.

If you look at this [https://discuss.inventables.com/t/this-should-be-fun] You will see I bought a small machine as a secondary to play around with and had to swap to a much larger spindle before it could really work. Took some customization but works great.

@BrianSaban That is a really nice mini machine.

@HaldorLonningdal Here is a video of the machine running smiley face project. Machine is setup with 1/8 steps at feed rate of 200.

Thanks for the video!

Looks like your X-axis is dragging. Is your X/Y position in the same spot after the carve have completed or has it shifted to the right?

Just ran job again. Looks like the X position has shifted by 10mm.

Then something is causing steps being lost on X.

Possible causes:

  • Stepper shaft spinning relative to the coupler
  • ACME rod slipping relative to the coupler
  • X stepper driver go into thermal shut down
  • X motor not given enough power to overcome drag/friction
  • Bad stepper driver (X)
  • One of the 4 motor wires have poor contact, causing occasional wrong direction which accumulates

I think it could be issue with the rods. I moved the carriage back and forth after removing lead screw and noticed that it get’s stuck in certain positions. I think the bars could have a minor bend. . not sure (rotated them and noticed carriage moved up and down).

Going to take the whole thing apart salvage the parts and maybe look at getting a better mini CNC machine.

Hello @HaldorLonningdal @BrianSaban. I took apart the machine and swapped out the Trapezoidal for Acme threaded rods with backlash nuts. Machine is working well and getting much better results.


Thanks for all your help!