BTT quality is a nightmare, don't ask me how I know. I wish I had started with RepRap and Duet board two years ago when I picked up the hobby, but then again, I've gotten an extensive education on what doesn't work and a bigger appreciation for what does.
@jens55 on a whim I touched up the solder on the 5v and ground pins on the fan board. Have it running on another pi that's running 2 web cams + a small display and hasn't had an issue yet. I'll test for a couple days. Maybe it was just bad manufacturing.
@leadinglights Thanks for the remark with the Chladni plates! I never heard of these before (not common part of school physics when I was a pupil at least), but this fits perfectly to what I observed with my oscilloscope.
Since my Neo print head would need complete redesign to include a piezo up there, I stuck with reading out the sensors that got crosstalk separately and am quite happy with the result. I see some repeatable measurement errors due to the varying flexibility of the print bed, but that is fine for me for now.
Hm... now that I think of it, it might be worth a feature request to be able to substract a given height map from a newly measured one... by doing this you could remove such measurement errors...
It works more reliably than any of the other forks.
Since BTT have released the SKR-RRF-E3, they've been more interested in getting the TFT to work with RRF.
I don't know of any major bugs anyway
I plan to make tests with pens, as Make Anything did; it is a very easy setup...
I already figured out, only 'permanent markers' stick to PLA.
I think, I've seen the video and their process is not able to produce real textures.
You'd have to dye the filament with a timed process. I'd better like to steal the mapping algorhythm from "velocity printing" and rewrite it to add ink layer by layer.
I don't expect perfect results, but a powder printer with inkjet is a bit above my budget..Let's see how bad it is..
Good to know, but I had no ringing or resonance on my prints, so I didn't bother using IS at all. (can we call it 'IS' ? )
With lower stepper current, I don't see ringing become an issue. (Acceleration was 1000mm/s² during the test. Before it was 2000) I could live with that...less noise but almost no difference in print time.
I guess, it's not speed but acceleration one has to think about - then It is clearer, at least for me 🙂
Yesterday, I tried how a piezo speaker I had lying around might react by gluing one onto the frame holding my printbed, roughly where the Andromeda would be mounted if I followed my initial idea. It turned out my spings are too stiff: the bed spring would rather bend the frame if I pressed onto the bed instead of giving in - and the piezo would barely detect anything.
After some attempts on how to fit everything into the available space (my printer has just 32mm beneath the printing surface with the z-axis being at its lower limit and the printer housing, meaning 13mm for the Andromeda and the adjustment screw), as far away as possible from the heating element and still keeping the adjustment screws accessible, the whole design - with the piezos nicely covered with a housing - looks like this now:
(the thin aluminum plate is L-shaped to give it more stiffness; that is cut away in the view. So it not quite as flimsy as it might look)
While this means I will have to drill some more holes into the z-axis frame, I definitely will see a signal now whenever I tap onto the bed with something. Now It's up to finding the correct settings for sensitivity - as soon as the sensors have arrived and I have assembled all this. Some miniature coaxial cable is also ordered 🙂
When this is running, I want to find a way if I can use the Piezos as "second" z-endstop (i.e. z-endstop controlled by the piezo elements - but in case these fail for some reason, the exisiting less precise endstop detection should kick a bit above that and force the Duet to retry...) but I will open a new thread for that topic unless I find something here in the forum.
i updated the first post with a link to the image. sorry about the quality of the first one. didn't know it was bad. i read somewhere that a duet2 running RRF3 wont work. however, there was a testDWA.py file inside the TAMV folder that was able to detect my duet2wifi RRF3 board when i entered my IP manually and it was able to display the correct X Y and Z position which i found was odd considering my machine is not a duet2 on RRF2 or duet3 on RRF3.