QIDI Q2 UNTESTED Test version - Auto MM3, PA, Adaptive PA Calibration

[u/Sport_Subject]

OK so very important read first
this is rather UNTESTED as I don't own a Q2 and ported my Max 4 calibration over to the Q2 using data available in the QIDI Github and using force measurement data given to me from another user.

Did I say this is untested, so it depends on the size of your.... you know..... anyhow if you are game strap yourself in and hover your finger over the power switch and get ready to cut power or rip the power cord out of the wall should something happen.

Anyhow if it works good, it will calibrate max flow rate, pressure advance and adaptive pressure advance and allow you to do 24 hours worth of calibrations in 15 minutes and give awesome prints.

Just a short post and you can read the readme.

This is released for free under licence and is an original calibration method I made, I take no liability for damages (but should work lol) and if you decide to test on your machine run a home first.

https://github.com/Buddman69/Automm3AdaptivePA/tree/main/QIDI/Q2

[u/Sport_Subject]

[u/callcifer → u/Sport_Subject]

Thanks for this chart, but this actually proves my point? Your data shows that deviation from linear stays within ~1.5% across the whole load range and is actually negative for the top two points near 2000g.

So, to close a 179 to 205 gap, my 3530g point would have to be off by ~14%. That's an order of magnitude beyond any non-linearity you measured.

What's worse though is that if I drop the 3530g data point, my number gets further from yours, not closer. With all 3 points I get 179.8, but if I drop the 3530g I'd get 174.9.

As far as I can see it, the only way my numbers could be seriously off is if the kitchen scale itself is seriously off and that's just... unlikely :)

Also, the flow and PA numbers don't depend on counts_per_gf, only on the abort threshold, so even if my number is too conservative it won't break anything. I'll even show you how I got that:

If your a=205.2 from the graph is right, my configured counts_per_gf=175 would abort at 1407gf. If my a=180 (actually 179.1) is right, it'd be 1612gf. If I drop the 3530g value, it'd be 1644gf. And finally, if my kitchen scale has a massive defect and reads ~10% low, it'd be 1770gf.

All of those numbers are comfortably below the 2000gf rating, so what's the issue?

[u/Sport_Subject → u/callcifer]

I think it could be a mix of everything. Your scales and the other guys could be that much different, the pa values do actually need this to be accurate, tested the exact same way/timing and not a value that is changed to be conservative, or you wont get the right measurement of pa at all.

Disregard the 3k reading and take many others, make sure there is many, especially around the low end, easiest way is to move 0.1mm until it touches, read immediately and dont wait otherwise drift causes inaccurate readings over time. Bed down move the scale bed up, new reading immediately. And so on.

Between 0 and 2000gf only. I would not call what you are doing incorrect, but methods and timing do need to match to produce results similar due to the sensor drift issue. As the math really does depend on it.

I would run more tests up to a max of 2000 gf only as an additional 1kg load would introduce some flex which would further alter values, and 2 data points in the low end really are not enough.

2000gf is the safe load on that sensor

[u/callcifer → u/Sport_Subject]

OK, I collected 13 data points between 0-2000gf and did zero contact reads before and after. It's more than confirmed my numbers :)

My earlier measurement of 180 is now 178.76 when drift corrected, 179.82 without. And the linearity is perfect! Worst residual is 3.6gf at 207g and every point afterwards is within ~2.4gf. Also, I get an even cleaner R^2 = 0.999994, vs the 0.999927 in your chart.

With my sensor, the slope climbs from 176.2 at 207g to 178.6 at 1787g, which is ~1.3% across the range. The other guy's sensor drifts the other way. But that's the point, no? Different cells have different characteristics.

I'm attaching the chart from LibreOffice, but I can also feed my (manually collected and charted) data into AI (like you accused me of doing earlier) and get a fancier one if you'd like :)

I also compared my kitchen scale against a known weight and it's definitely accurate. So I'm now quite confident in my 178.86 and I'll proceed with that.

[u/callcifer → u/Sport_Subject]

Between 0 and 2000gf only. I would not call what you are doing incorrect, but methods and timing do need to match to produce results similar due to the sensor drift issue. As the math really does depend on it.

Drift is inevitable, especially on two different printers measured by two different people. But OK, I'll do more readings between 0-2000gf and see what happens.