After a long hiatus, my trusty printer is now back online. The hiatus has partly been due to a series of problems, partly due to me finally getting my shit together to do a proper workbench in my room (another post coming on that soon). Among other things, I replaced my Melzi with a new and slightly nicer one, though I'm not now sure that the old one was actually broken - turned out despite my testing the D-sub connection was done wrong. I was tempted to get one of the
TronXY models which come with nicer connectors, as connecting raw wires in a cramped space is not easy and rather error-prone. I just don't know if they're truly compatible, and haven't been able to find any evidence one way or another. They seem to be Chinese knock-offs, and what I have seen about them doesn't sound encouraging, but then people only post when complaining, so I don't know.
After a number of rewirings - it seemed every time I fixed one wire another started having trouble - I now have it printing again, except the print fan is dead. That's not just a wire problem, I applied 12V straight to it, and it didn't react. So that needs to be replaced. It shows quite clearly on this McBenchy:
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| Ridges on the brow and drooping above the door - sign of a missing print fan |
I have changed the hotend fan to take 12V from the hotend + on the breakout PCB. This is in preparation for putting in the probe, which should use the spare P pin as signal. However, I would need to put in either resistors or a voltage regulator to get the signal down to 5V, so I will probably need to redo the board to support that. Yes, I could make a tiny side board for this, but I have had it with messy setups. At the same time, I could change the connectors to some that are easier to plug in and out. This is the
most informative thread on the current layout wrt probes. That thread says to not put too much current through the shared thermistor ground, this fan uses 150mA, which might be a problem for the thermistor, maybe. The probe wouldn't add much. If necessary, I could draw an X limit ground wire, but I would rather not. I think the lack of spare wires into the breakout board was somewhat of a false economy, it makes it hard to upgrade. There are also potentially good links on
this thread.
