Bartman's LR3 build thread - A New(bie) Adventure!

Well it’s been a frustrating few weeks.

I got the new build mostly assembled, and found that the wiring for the end stop switches was too short to reach the controller box. I didn’t have all of the crimp terminals and tool to make plug in extension cords, so I cut the existing cables and soldered some wire in the middle. Unfortunately I didn’t notice that one of the spools of wire that I used was #24 solid, rather than stranded, and a couple of the solder joints kept failing. This resulted in intermittent “Triggered” states on a couple of the end stops. I ended up cutting out the original splices and inserting sections of twisted pair #24 wire, and things started looking up - for a while…

The next thing I found was that the changes to the wiring resulted in intermittent “pull up resistor” issues, especially with one end stop in particular. In some cases, everything would work as expected for initial homing, but after travelling to the far end of the table and back, the end stop would try to continue past the end stop block, even though the LED would assert. It was frustrating, because I couldn’t do the M119 command as it was grinding through the end stop block, and when I was able to do an M119 command after power cycling, it would mostly show as triggered. I ended up soldering on some 1.5 kOhm resistors to the underside of the board, and that seemed to fix the problem. Everything was going great until…

As I was sliding the controller box cover on for what I had hoped was the final time, I felt a bit of resistance, and then the LCD screen went black. When I removed the cover, I discovered that the 3.3V LED was not lit, and there was a dead short between 3.3VCC and GND. I rechecked the resistors that I soldered on, and there weren’t any obvious solder bridges, and I inspected the cabling, and even removed all of the connectors, and there was still a short circuit. I tried to remove F3 fuse from the board to isloate the section where the short was, but my SMT soldering skills weren’t up to the task, and I ended up desoldering a nearby resistor, and pretty much making a mess of the board.

After debating with myself whether to stick with the SKR board or go with a Jackpot, I decided to stick with what I knew, and ordered a replacement from the Biqu website, as there was free shipping to Canada. It arrived in the mail about 10 days later, and I installed it yesterday, thinking that I was finally on the home stretch. Until…

I pulled off all of the plastic JST connectors so that the Dupont cabling connectors would fit, removed all of the excess jumpers, swapped the drivers from the old board, wired everything up, flashed the firmware, and powered it up. Then I got the very disappointing “ERROR: ALL LOW” warning message on my screen.

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I swapped drivers, and then swapped motor wiring between Z and Z2, and in each case it stays with the port. The weird thing about the message is that it says that Z has the error, but it is actually Z2 that isn’t moving.

So I have opened a ticket with Biqu support. I’m hoping that this gets resolved without any drama or added cost. And I’m really hoping that this is the last in a string of unexpected problems .

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