Rambo 1.4 Not turning on with dual end wiring

Last week I was able to still manually move my MPCNC with a series wiring setup through the lcd turn knob piece/screen. This past week or two I’ve been resetting my MPCNC with a dual end stop wiring setup and rewiring my board. It has sat out in the barnshed for a while but hasn’t had issues in the past. In the last few days with my new wiring plugged in the board would not start up nor light up -Neither Rambo nor LCD turn knob screen. After reviewing the forum I’m going to look into checking the fuses to see if I blew/short-circuited something. For now, I’d like to post my pictures and get feedback from the community on what I may be doing incorrectly.


It looks like your endstops are connected between (+) and (-). They should be connecting (-) and (s). You’ve shorted the 5V. Hopefully it’s just a blown fuse.

You didn’t ask for this feedback, but the height is huge. If you’re planning on milling wood, the length of the Z axis and the size of the legs are going to really reduce the rigidity.

Lasyly, I see the camera feed. Be very careful to not leave your cnc alone while milling. It’s not obvious, but the fire hazard is worse than a 3d printer. If something goes wrong and the bit or collet start rubbing, they will smoke in less than a few seconds.

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Thank you for your input. First on my agenda is to connect the endstops correctly. I didn’t notice any blown fuses, I’ll check the big fuses… to see if they need to be replaced after ohming the 3… after that I’ll further inquire what else could be wrong with my board. That’s my main reason for posting on forum.

2nd, I have shorter legs. Was just having trouble adjusting height with original series setup long ago. The z piece would drag on my cutting surface while crown cutting, hence long legs while I wade in the water and have significant offset… metaphorically speaking lol. Any z offset configuration advice I’d appreciate a link :slight_smile: your advice is appreciated tho. I intend to reduce leg size once I know how to properly operate my cnc.

3rd the recording was with my spyhat while I was present. I’m wanting to setup my YouTube channel to document my projects and I believe I could garner better community feedback on my progress from more awesome people like you with video so that I’m setup properly. I’d like to manufacture more open source CNC’s myself to fabricate wikihouses and seed eco homes.

Sounds neat. Definitely disconnect those endstops before trying to turn it on again. Shorting + and - is not good for the voltage regulator.

Just a recap of order of operations:

  1. Pull out endstops try to power board / troubleshoot
  2. Correctly wire endstops
  3. Ohm fuses... should be 3 to check?
  4. Order fuses from ultimaker if readings off
  5. Install new fuses and look for power LEDs

That looks right.

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Looks like moving my dual endstop wiring connections did the trick. Both my old and new boards are both working with lights on and manual turn knob movements. Next on my agenda is to calibrate homing for the limit switches and finish the crown tutorials. I’ll look into #endStopCalibration in the threads… Then cut the wikihouse. Also, flat parts arrived for my lowrider2 so I can finish assembling my kit -but that’s a different forum section…

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