Cohesion3D Remix for K40 dropin replacement

Machine: K40

Board: Cohesion3D Remix

Firmware: _Smoothie - but I’ll GRBL-LPC if I need to.

Problem/ Question: Trying to upgrade my K40 with the Cohesionb3D Remix board, but when I go to move axis, it does nothing, then says “can’t write” and times out.

Help. I am using latest config sample from cohesion smoothie GitHub.

In order to help pictures of your machine, original board, and wiring would really be required.

It would also be super helpful to know what software you are using to send the commands.

Hi Chris, thanks for the reply.

My K40 came with a LIHUIYU M2 Nano 6C6879
[not my picture]

I’ve tried both Pronterface and LightBurn with the same result

On my cohesion board, I have L going into FET P2.5 and configured my config laser pin as so. Does it need to be grounded? How should I wire K-K+ G IN 5V to my board instead of the original control panel?

My reprap discount display doesn’t turn on at all (via USB or 5v). I have it configured in the config.config.txt (25.0 KB)

current setup:


Have you got some better pictures of the connections to the LPSU and Remix board? It’s very difficult to see where things are connected in that picture. Maybe with labels or a diagram since they’re all blue?

I have L connected to FET P2.5 (bed heater -) and 24v and gnd wired to the 24v max

Nearly nothing is connected in these pictures.

Also it’s much better for both the stability of the C3D remix and the lpsu to use a separate 24v power supply.

In the top picture, I’d unplugged the wires so that it’d be easier to see the how the ports are labels.

Should k-k+ and G IN 5v be wired to my cohesion board or stays hooked to the original display board? What all should be hooked onto the cohesion board? Other than L, 24v and its GND, endstop switches and motors and display exp cables?

I am now sometimes able to get it to report status with M122.

So this is what the ReMix board I sent Scott is doing :slight_smile:

So you know, the ReMix was not the K40 drop in, that was the C3D Mini and now the LaserBoard.

Try to follow the concepts in these instructions:

And there is a wiring diagram for the ReMix here:

You need X motor, Y motor, endstops to X Min and Y Max and L and Gnd to fire the laser.

L goes to P2.5 bed - output, and you’ll need a ground from the Laser PSU to the board ground shared as reference for that signal.

However, you should use a separate 24v power the Main Power IN screw terminal on the ReMix.

Finally, use the firmware and config files at the bottom of the install guide, the pins should be the same as the C3D Mini, although you may want to double check me on whether I used the Y Min or Y Max pin on the C3D Mini and config file.

Also, DRV8825 means you will need to double the steps per mm.

That should be it.

We don’t remove the pot/ digital panel. Read the FAQ section of the forum to learn more.

Yes, we’re trying to put it to good use and what better than with a K40.

What I really meant is that I want to use the ReMix as the replacement.

I was following those guides but was confused on where exactly L goes and where to ground it. Thanks for clearing that up.

Don’t have a spare 24v PSU atm, will pick one up.

Okay, so it turns out that with the LCD plugged in, the USB is not recognized on the computer while M503 and such returns missing information. I’ll try a different one later, but I’m pretty sure this one was functional.

With the LCD unplugged, I can see the flash disk and send commands. I’m using the 2nd batch files. Had to change Y Max from 1.26^ to 1.27^. Can’t get any movement out of either axis though even with steps_per_mm changed to 315.15. Also tried 400.

So I had the 24v line going into the 24v max instead of vmot. Hooked it up to VMOT and everything is okay now after adjusting the VREF.

We did accidentally shorted the system and now the L1 led doesn’t come on, but everything appears to be operating just fine.

Next is sorting out the LCD issue.

Got a genuine RepRap Discount GLCD and it works great. Just had to change ‘buzz_pin’ to 1.31. It squeals on startup each time though, but I’ve read that this is normal?

Enabling network still causes the board not to boot up fully. Only a solid green led is lit (in addition to the red led), and the computer doesn’t detect the USB device. Printing from USB still freezes mid job for no reason. I’ve done all the suggestions found on other threads: quality USB cable, ground case, check all lines and endstops, printed a plastic mount and using separate power supply for the board.

I will try to run a job from SD card later.

If you don’t have a ethernet module plugged in, and enable network in the config file, the board won’t boot.

I would recommend using the batch 3 files from the C3D Mini k40 instructions.

USB is not recognized when I use batch 3.

Is it possible to set up the web interface with the board’s wifi card?

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