Revnull LR3 Build, my 1st CNC

Oh absolutely, but I know me. If I have to ever replace it, I will forget to bend the new one then proceed to break off the lead screw holder as it overshoots on homing. The small modification to the endstop holder is better for my particular brand of forgetfulness. If I get it to work and others find utility in it, I can post it for public consumption, if your license allows (I still need to read it).

Nope, the steppers will skip. That is a part of the reason not to use Giant Nema 23’s.

Absolutely

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It seems like 6mm extension was the trick. :slight_smile:

I’ve posted them on printables if anyone else can use them.
https://www.printables.com/model/252250

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Hi

Is this case remix generally available?

I printed and glued a little landing for the XZ plate finger to make the switch hit a bit better.

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I’m not sure about generally available, but @jeffeb3 post a link to it in the thread below. I had to create an Onshape account to access the project and export the STLs.

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This morning I was determined to get this thing to move. The Pi ZeroW fits well in the space and has room for a micro USB power connector, but the GPIO headers and a little too close to the SKR to use standard dupont connections. :frowning: I guess I could remove the header pins and solder directly to the PCB, but that feels a bit permanent for my liking.

There were a hand full of times the load was a bit high so I thought I’d try a 3B+. The SKR’s 5vdc regulator seems to have enough extra mA to power the ZeroW, but the the 3B+ was throttling and under-volting so an external buck will be required. I’m a bit perplexed on how to power this thing since the micro USB power port is blocked and the BPIO header is too tall. I think additional remixing will be needed. Maybe add a couple of mounting holes for the buck. :slight_smile:

The SKR 1.3 fits like a champ! Though pictured, I had to pull the 3B+ out of the case until I can find a way to power and cool it in the existing case. @jeffeb3, any suggestions?

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I am using an external buck/boost converter and I soldered straight to the 5V and GND of the input power micro usb. That way, the pi uses its own circuitry to filter the 5V a little.

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It lives! Albeit a bit squeaky at the moment. I’ve been able to translate most of the V1 marlin changes into klipper (as far as I can tell) and it moves where I tell it to. Time to build a table I guess.

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That’s what I was thinking too, but was hoping to avoid. Did you have any issues with overheating?

It is only on when I am using the machine. I haven’t noticed any.

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What software are you running on the Pi? Is there anything that lets you know when you exceed 60c triggering CPU throttle or under-volt?

I’m thinking of spinning the Pi 180 degrees so the ports are externally available. This would also make the Pi’s SD card more accessible. Dropping the Pi down a few mm also would make the GPIO pins more usable.

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Externally exposed USB ports can be used for cameras or in the case of Klipper, external “MCUs” for extended control.

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Since the angles of the case are kind of wonky anyway, we can move the Pi to a flat surface. This gives much more room for the GPIO headers
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If we also slide the SKR board towards the middle of the case, it will expose the micro USB power port and widen the gap for stepper cable routing.

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A little more tinkering. Added mounting spot for a LM2596 buck

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Added a 3010 fan to help keep things cool. I think I need to play with the Pi holes a bit. I’m not 100% confident in the Pi model I found.

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Hack job complete. :smiley:

Changes:

  • Lengthened case by 20mm to accommodate the shuffle
  • Shifted SKR board back to make room for cable routing on all sides of the PCB
  • Added 30x10mm fan to keep things inside the case cool(er)
  • Rotated Raspberry Pi to externally expose ports and re-oriented to be parallel with the bottom of the case.
  • Added mounting points for LM2596 buck converter to power the Pi.
  • Relocated V1 logo cutout to the right of the Pi to accommodate power ingress.

Time to test print I guess.

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Because of the environment where this will be operating I would arrange for plugs/covers for the Pi USB and RJ45 ports to prevent dust and chip contamination. Should be easy enough to arrange, I think

Going to need to add a little slack space around the USB ports, but everything seems to fit as expected.

Just printed partial height to test screw hole spacing. So far so good.

Not a great picture, but is does show proper spacing between the Pi and the SKR.

I’m making the final adjustments and hopefully final print tonight.

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Nice and compact, solid edit right there!

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Fits like a glove. :smiley:

Plenty of room for wires and other bits. I think I’m going to replace the 5vdc fan (Pi powered) with a 24vdc that will be controlled by the SKR. The best part is I can switch back to UART control and forgo the giant USB connector. :+1:

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