Teensy 4.1 + LinuxCnC for 8 axis Motion Control

Hi there! Just joined the form and glanced at a few threads. I'm currently developing my own motion control system for miniature photography. My current setup would require 8 axes (all are stepper motors).

I'd like to write a tight package extending off an existing one here. The intent is to animate and export FBX files from Modo, import it using Autodesk's FBX SDK library, and parse them into gcode. The gcode file will go through a modification pass where I can set focus pulls in real-time with a jog box. Then the camera's shutter speed (by default 1 second exposure) will be input to modify the overall speed and acceleration of the animation.

Here's an example of a typical shot:
I'd like to photograph a 5 second flyby shot of a spaceship. There are two main rigs: the camera and model mover. The camera rig has 4 "axes:" track, camera yaw, camera pitch, and focus pull. The model mover has 4 axes: yaw, roll, pitch and a stepper motor in the miniature to animate an element.

The gross movement of the shot will be animated in Modo or Maya, exported as an FBX, and imported into the linuxcnc modified package. The FBX file will then be parsed into gcode. I will then program the focus pull into the gcode with a custom jog box and indicate the appropriate exposure time to modify the speed and acceleration. The program will run very slowly as each frame is a 1 second exposure. In the case of this example shot, 5 seconds is 120 frames (5 x 24). However, a 1 second exposure technically will take two seconds to mechanically operate. So in reality the entire shot will take 240 seconds = 4 minutes.

I know there have been threads in the past around the topic of LinuxCnC + Teensy 4.1, but they are often laced with heated debates that make it difficult to find tasty info. Is there a LinuxCNC + Teensy 4.1 package on the market right now? I've seen one module but it only supports 5 axis. I'd like to find a package that supports 8+ axis out of the box, so I can just add a treatment pass for my use case.

I'm commissioning this guy off ebay to make me his 8 axis driver package without the mach board:

Thanks for your time!

The is not a Teensy 4.1 driver that will work out of the box. There is an imx.RT1052 driver for a chinese ethernet card which might be a good place to start, but it will require work.

If you are looking for 8 axis out the box, you can do a Mesa card + 2 driver boards. It will be the most polished and have the best support/performance.

But if you wanna try something cool and fun, these boards support 8 axis out of the box. They are small and cheap also. For these to work, it is required you use an RPI4 to run linuxcnc

remora-docs.readthedocs.io/en/latest/hardware/octopus.html
remora-docs.readthedocs.io/en/latest/hardware/spider.html
remora-docs.readthedocs.io/en/latest/hardware/monster8.html

I think your option of the Mesa card + 2 drivers sounds appealing. After a bit of digging, I think 2 x mesa 7i77s coupled with that dual gecko g540 package might do.

Do I have to then buy a supporting card like the 7i92TF to use it? The site says I can use a single 7i92TF for dual 7i77s. If I do that, I need to somehow take both db-25 outputs on the gecko g540 and combine them to a single Ethernet output for the 7i92TF. I guess this could be done with a simple breakout board. Or is that step completely unnecessary?

Thoughts?

I hear you and I appreciate the warning. However, as of recent, I’ve heard great things about the g540 and this guy I linked in the first post sells a great package out of the box that should work. I just want to reduce all the extra steps so I can get straight to modifying/adding to linuxcnc when possible.

If you are going to use s 7I92, I would chose a 7I92TH
so the two cables are identical (DB25M-IDC26)

Great! I appreciate the clarification. Is there any other piece of hardware I should get then on that side of things or would I go straight to configurating/programming?

Forgot to ask, but is it possible to implement an SDK into LinuxCNC? I want to implement the Autodesk FBX SDK which is in C++