@Jacotheron Finally had a chance to test this with Fusion 360 and it is working for milling. Thank you!

Saw this posted on reddit and wanted to share:

YouTube link

I'm building a tool-changing printer with two independent z-axes (one for each tool).

The Duet thinks there is only 1 z-axis at any given time, so I use M584 to switch stepper outputs during tool changes.

(dc42 suggested this method here: https://forum.duet3d.com/topic/16609/multiple-z-axis-and-complex-tools-possible)

Is there a way to get each Z axis to move in sync during a print?

For example:

Printer homes and both axes home to their endstops. T0 & T1 Z-height are both at 0

T0 starts the print and completes Layer 1 & 2

Tool-change to T1

T1 Never moved from its homed position (Z=0) so it will crash into the print.

Does anyone have insight to ensure that both T0 & T1 move upward as the print progresses?

Ideally, each tool would move to some intermediate position defined in Tfree, and the return to the correct z-height for printing when it becomes active again.

Thanks!

In the photo, T0 is on the left, T1 is on the right.

Hey, exactly what @Jacotheron said. Here are a couple of post processors found on the forum, but you can search for others too. You'll have to try some out and see what works best for you. If you find one that works, you may also need to manually edit the Gcode to add or remove commands as needed (I have to do this).

I've used this with success:

https://github.com/mwinterm/fusion_post/tree/master/DuetCNC

I tried this but it didn't quite work for me:

https://github.com/guffy1234/mpcnc_posts_processor

Search google for how to import a post-processor into Fusion360

@taconite Hey any thoughts about preventing heat-creep after a (hot) tool is placed back on the carousel?

@JoergS5 There may be hope... I contacted the author of that topic in March and they said the linear rails had been sent off to be EDM'd.

@bot I too have been dreaming about using linear motors in a build. I've heard they can sometimes be salvaged from old electric typewriters from the 80's like the Daisy Wheel or Brother EM series. But I don't know if those are suitable for a printer.

I had an issue like this that was caused by a poor ribbon cable connection between the Duet and Pi. It usually required that I reseat the cable before DWC would work again, but It was also somewhat unpredictable.

I replaced the ribbon cable with some jumper wires and the issue hasn't returned.

@oozeBot

My deviations show -0.117/0.315mm and I get ok results.

Somewhere on the forum I read that larger deviations may require a higher Z-axis acceleration setting so that the printer can move up or down fast enough between probed points while printing. If that's true, then I'd guess that it shouldn't be a problem unless your Z-axis mechanics aren't suited for big velocity changes because of backlash in the z-carriage, etc.

@3DPMicro Hey, I don't think so, but that would be a nice feature for tool-changers/Dual extruders.

Here's a post-processor someone made for the E3D TC that adds that functionality:

https://github.com/mkudzia84/toolchanger-pspp

Not my printer, but wanted to share Vez3D's ODrive set-up on a corexy printer.

ODrive is a BLDC controller which can drive 'lower'-cost bldc motors via several input methods, including Step/Direction.

Vez3D is using it as part of the benchy speed boat challenge.

Here's a long video going over the configuration for a printer:
https://www.youtube.com/watch?v=1XzD7lGNaek&t=1885s

And an example print (~30sec):
https://www.youtube.com/watch?v=RfqWyzq5osU&ab_channel=Vez3D

@dc42
@OwenD
@theruttmeister

Thank you! This gives me a good starting point.

I'm using an E3D toolchanger with a syringe dispensing tool. I'll be slicing models normally, but I'll need to post-process the gcode to add commands at the appropriate points to turn a pneumatic pump on and off.

Then I thought, maybe I can avoid post-processing and use conditional gcode to turn the pump on/off based on a state (or set of states) in the object model.

For instance, the pump should be off during travel moves, so can I reference the object model when the print speed is above a certain threshold and use a conditional loop to turn the pump off.

Post-processing still seems like a good choice, I just wanted to check this idea with you all.

Not my printer, but wanted to share Vez3D's ODrive set-up on a corexy printer.

ODrive is a BLDC controller which can drive 'lower'-cost bldc motors via several input methods, including Step/Direction.

Vez3D is using it as part of the benchy speed boat challenge.

Here's a long video going over the configuration for a printer:
https://www.youtube.com/watch?v=1XzD7lGNaek&t=1885s

And an example print (~30sec):
https://www.youtube.com/watch?v=RfqWyzq5osU&ab_channel=Vez3D

What might cause the cursor to be offset from the rendered preview?

I'm using a Toolchanger, so each of the tools have offsets with respect to the Z-probe. Perhaps the offset is not being referenced?

@oozebot I really enjoy seeing your posts. Looking forward to the launch!

@gnydick What's your method for measuring across pins?

Measuring directly at the pins with the probes is risky because it's very easy touch the probes by accident and cause a short.

When I need to measure something on the board (e.g. voltage at fan header) I plug breadboard jumper wires into each pin to extend them, then I measure them far away from eachother.

@3dpmicro Thanks for the info. I had wondered about those bellows for a long time, but never found a company willing to sew them with the hexagonal shape you described (they were always simpler, flat bellows).

Toaster ovens are very common and can reach high temperatures.

Maybe one could build a motion system external to the toaster interior for x-y movement (e.g. corexy) and have a bed that can raise and lower within the toaster.

I guess you'd need to cut out the top (or bottom) of the toaster for access. Some ovens already have a hinged panel for cleaning.

For XY, you'd probably need a high-temp bellows (à la Stratasys machine) to prevent convective losses.

The heating elements could be controlled by relays, and some ovens have a fan for air distribution.

Crazy idea?

...or crazy enough to work ? ;^)

@3DPMicro Hey, I don't think so, but that would be a nice feature for tool-changers/Dual extruders.

Here's a post-processor someone made for the E3D TC that adds that functionality:

https://github.com/mkudzia84/toolchanger-pspp

You'll have independent z-axes? I was building a machine like this in the past. Here is a relevant thread for dealing with the different z-axes offsets. It worked well enough.

https://forum.duet3d.com/topic/18051/printer-with-two-independent-z-axes-how-to-synchronize