Kossel Mini : One step forward, two steps back

Hey guys, this was written a while ago, but didn’t have the time to finish until recently.  Many things have changed, I’ll try to summarize them ASAP!

Just to recap, the Kossel Mini was set up and performing pretty well – until parts started to fail(due to wear?).

There was a lot of talk of using FSR or induction probe instead of a mechanical key probe, and I figured this is a good chance to upgrade to FSR.  FSR, or Force Sensitive Resistors, offloads the switch from being affixed to the carriage next to the hotend to the bed, via three FSRs wired in parallel.

Unfortunately I don’t have any photos from this setup, as I had a hard time leveling the bed afterwards.

It looks like the issue is that with 3 FSR pads, I do not have an even pressure being applied to the surface, so one side of the bed registers with less force than another side.  This is certainly not good, but it also makes this a harder issue if I have to calibrate the 3 areas.  My understanding is that the probe is supposed to compensate for bed irregularities.

So I figured one way to get the bed level once and for all is to get a bed that rests on the frame instead of the PLA printed tabs for the 160mm bed.

Instead of buying a larger circular bed, I opted to get a mirror plate from IKEA and cut it to rest on the frame.  The idea is that the bed resting on the frame(which should be perpendicular to the pillars) should make it level, or very close to it.

But while I was trying to re-install the probe(hey, this experiment may result in me going back to stock!), I broke the hotend.

To be fair, the wires snapped off with almost no resistance, which tells me that it was on its way out already.

I wonder if this is also the reason why I’ve been experiencing print failures.   Although, Simplify3D monitor didn’t show any erratic temperature readings.


Anyway, now I should look into getting a replacement/upgrade the hotend.


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