alden

The project files for Studio 6 and Studio 4 are in the support directories in edge and dev. Have fun!

Mr SystemsGuy,

Thanks for sticking with it. I actually drafted a response earlier but didn’t post because I wanted to fry a few things out first. But you beat me to it.

The Z axis on the Shapeoko (or ANY machine) can be tricky if it’s not perfectly aligned.

-I’d start with the machine and see how free you can make the Z axis spin – mechanically. You might try some light oil in the delrin nut as well.

-The next place to look is the current setting on the Z axis. It might be able to go up a bit. If it starts cutting out due to thermal overload you have gone too far.

-You might also drop Z down to 4x or 2x microsteps. You will get more torque at higher speeds this way. Balance torque with smooth operation

Thanks for checking back in. I’ll probably change the default Z setting in the profile to 1000 so people can tweak up from there instead of hitting a problem. How about those 16,000 mm/min X/Y rapids!

Alden

Rick, The answer to your question depends a lot on what version you are using. I’ll answer the question first for what you are probably using (version 0.94 or earlier), then for the branch currently in Dev – soon to be in edge – which is the 0.95 behaviors. A lot of work has been done on homing and limits for 0.95.

0.94 homing. See this page:

https://github.com/synthetos/TinyG/wiki/TinyG-Homing-(version-0.94-and-earlier)

All switches actually work “in parallel”, and work for normally open (NO) switches only. So any NO switch can be wired to any port – but avoid the A ports. So you could wire switches for Xmin, Ymin, Zmax (a common homing config) to the Xmin, Ymin and Zmax pin pairs (input and gbn per pair), or you could just wire the the first 3 switches (which happen to be Xmin, Xmax, Ymin). You need to configure the switches via the $xsm parameter (and Ysm and Zsm) for Homing, or for homing and limits.

Adding a relay for electrical disconnect is a good idea as well.

0.95 homing. See this page:

https://github.com/synthetos/TinyG/wiki/TinyG-Homing-(version-0.95-and-above)

0.95 homing supports NC and NO switches, and actually requires switches to be connected to the correct line. This is necessary for NC switch support. The $xsm param has been replaced by $xsn and xsx for min and max, respectively, also for NC support. NC switches are much more noise immune and are recommended over NO connections – especially if you intend to use them for limits. The spindles often trip the switches with noise, and spindles are not normally enabled during homing.

The page should describe all else. Please let me know if this is clear, or go in an edit or leave comments and let me know. It’s an open wiki.

Alden

The main question is whether or not the drivers on the grblShield are adequately sized to drive the motors and the mechanical system. The drivers will put out up to 2.5 amps (we recommend cooling about 2 amps).

If the machine is not well constructed there may be issues with friction in the drives which would load the motors heavily. You might try turning the gantries by hand to find out.

Also, are there dual motor gantries? In a machine that big I’d suspect so. GrblShield is designed to drive a single motor per axis. Although it’s possible to slave 2 motors to a single axis, the total current of both motors should not exceed the driver limit.

Alden

It can be done, but it would involve you (or someone) writing the kinematics for CoreXY. There is a section of the code in the kinematics.c file for inserting the inverse kinematics for conversion from cartesian to non-cartesian dynamics. There are a limited number of machine cycles so the transformation would have to be pretty efficient (running in less than about a millisecond, altogether), but I suspect a CoreXY transformation on only X and Y should be possible.

I hope this helps – given that there is no native support for this right now.

Alden

Thanks for the compliment. Some of the grblShields were manufactured with red LEDs, not green. They all light up because grbl enables all axes when any axis moves. This is all normal behavior.

–Alden

Matt, Cool. Let us know if you are making another video.

Also, I know you are aware of the JSON changes we are making in the dev branch, but I bring it up here in case any of our millions of readers are not already aware of this.

–Alden

This might bee a bug. I will try to reproduce this and see what’s going on. I have logged this as an issue (#28) the synthetos tinyg gihub.