Thursday, 4 May 2017

The Re-Birth of a Z Probe Mount, and a Discovery About Tension

Z offset Tuesday morning: 1.0. Air pressure 1017hPa. Humidity 26%
Z offset Tuesday evening: 1.1. Air pressure 1016 hPa. Humidity 30%.

Moving the X axis adjustment block inwards made it impossible for the knob to fit in the hole. V7 of the modded Z probe holder coming up.

Interestingly, two prints of this came out very differently. One had ringing, oblong cylinders, ragged walls, and big gaps in the top. The other was nigh perfect. Given that I had been fiddling with the X axis belt tension between the prints, that rather hints that a lack of tension can cause all of the above.

Bad tension: Top part shifted, top layers have holes, rining on the side, cylinder is oblong

Good tension: So much nice

V7 came out nicely, so I'm printing the full piece. I also took the opportunity to align the bed left-right, figuring my fiddling around might have thrown things out of whack. And indeed, it was quite slanted. After straightening, the Z offset was 0.2! That's pretty extreme, and shows I can't use the Z offsets and humidity/pressure/temperature readings as long as I'm messing with the X axis.

Calibrated the X axis left-right and got totally different Z offset with the same pressure and humidity. I figured if the tension is this important, I should measure it. What better way than to use a guitar tuning app to measure the frequency? First I tuned it to 124 Hz, but when doing the bed calibration the X belt actually came off, so that must have been too much. Going down to 103 Hz doesn't make the belt slip, so that's probably about right. For tuning, I used Guitar Tuner with the phone lying on the bed and using a hex wrench to strum the belt.

The Z probe mount in place. I need to figure out the electronics and software parts before I put in the actual probe.

Printed the Extensible Battery Dispenser in AAA size.

Z offset Wednesday evening: 0.1 Air pressure 1016 hPa. Humidity 30%.

Printed tiny bananas for scale. Photo coming when they have been painted. Also printed banana doorstop, but it should be done in the flexible PLA to actually have traction.

Z offset Thursday morning: 0.1. Air pressure 1016 hPa. Humidity 27.%

Printed AA battery dispenser extension, but it failed since part of it was just... missing:

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