Posts made by MJLew

@Ozzzzzzy Most of my printing is of gcode that I construct with my own custom code generating software. Hand-coded, if you like.

I used to use arcs extensively when my Duet-equipped Voron was my primary production printer, but I bought a Prusa MK4 and found to my horror that the firmware at that time did not properly support arcs! I changed all of my code to eliminate arcs. Finally, a long time after my prompting* Prusa added arc support to the firmware but my experiments suggested that arcs caused gave stuttering movements with blobs and zits and so I did not go back to arcs.

*I suspect that my questions and complaints did nothing to accelerate the incorporation of arcs into the firmware, as it was when PrusaSlicer integrated an ArcWelder-like feature that it was done.

@Ozzzzzzy "This is a post-processing script"? I don't see a script beyond the snippets, and I don't see a linked file. Download the script from where?

@Ozzzzzzy I do not find this post to be readily understood. Is it a suggested firmware enhancement or something else? Is there a post-processor that I should know about? Are there parts missing?

@Timothee-Leblond The absolute extrusion command make the extruder go to the E value so when you have E2 on one line and E0 on the next the extruder retracts 2mm of filament when it executes the second line.

Use G83 to set the extrusion to relative and then the first line will extrude 2mm and the second line will extrude 0mm.

@fcwilt Construct3D printers have Duet boards: https://construct-3d.com/

It sounds like it might not be possible to use the flow information to modify the print speed soon enough to work for you, but maybe you could use the flow rate information to modify the extrusion amount if you have a servo motor for the extruder instead of a stepper.

The inevitable delay between extrusion and the measurement of flow will be suboptimal for the control of the servo, but I dare say there are ways to deal with it.

@vbtalent2 It looks like either the nozzle is too far from the bed or the extruder is not extruding enough filament. The symptoms of both are pretty much the same. Have you confirmed the nozzle height and the e-steps?

@Macgyver This might be an old bug reappearing.

See here: https://forum.duet3d.com/topic/1816/config-file-vanishing

And here: https://forum.duet3d.com/topic/11266/config-file-disappeared?_=1722326054025

And another old one from me that I can't easily find.

Is Cura using absolute extrusion values? If so then the retract code will unload the filament by unwinding the extruder all the way back to -2. My guess is that putting in an M83 (extuder to relative) immediately after the G91 and G90 lines will fix your problem.

@jens55 Looks to me like there is a directional problem with the part cooling. If so then you should be able to rotate the part in the slicer and have the blobbiness move to a different place on the print but stay where it is relative to the printer.

If it's just generally inadequate part cooling then slowing the print down will probably help as it gives more cooling time relative to extrusion.

@DonStauffer The LiveCode development environment in which I mostly work has automatic variable typing, which is VERY convenient, but you still need to test for arrays using something akin to "if the keys() of [variable] is not empty then". That works without a hitch, but I avoid it by being diligent in appending "A" to the name of any array variable.

@adhanabal How?

@penguinya Yes, it's operating on Prusa MK4 and XL, but I had to turn it off on my machine because it was falsely triggering on the first layers when they had low layer height. I suspect that there might need to be some exception incorporated for those circumstances.

They have described it in these release notes.

@cgrosbeck What @oliof says about belts might well be true, but my next printer is likely to be a dual-gantry like the DuellingZero.

My plan is to stretch it along the y-axis to give a printing area of about 150 by 300mm. The short x-axis will allow it to be light and to use some nice THK rails that I acquired second hand a couple of years ago. I find my Duet-powered Voron 0 to be a very nice printer for my purposes, so a larger bed is not important to me.

@bernardomattiucci The time integral of acceleration gives velocity and the integral of velocity gives you distance, so the calculation is mathematically possible. I think that such a calculation is part of inertial guidance for rockets. However, any errors accumulate over time and so the position calculated that way becomes more and more inaccurate unless there is a way to repeatedly anchor it to position determined more directly.

@Richard-F Yes, that is an excellent idea. And it's one that has been had before. See the "Gunstruder" on thingiverse (https://www.thingiverse.com/thing:1247952) and a series of videos by "Proper Printing" ona different design (https://www.youtube.com/watch?v=-LdFmPYItb0)

@aytact If the fan is blowing enough to cool then I think that there are two things to check.

First, is the air actually getting through the fins of the cold-end? Air has to have somewhere to go after it gets to the fins.

Second, what are your retraction settings? If there are lots of long retractions in a short time then you may be pulling molten plastic above the heatbreak.

@MikeS I can confirm that the code generates the first shape in NC Viewer (although I default to mm instead of inches and so mine looked smaller than yours).

There are not enough lines of code to generate the second shape, so you must have lost a couple at some stage.

@o_lampe Thank you for the good design advice.

Yes, I expect to end up with a fairly small build volume, and in some ways you are right in suggesting that I build it larger. However, the space available in my shed is quite small and I would like the new printer to be not much wider than the Voron 0 that it will replace.

I have found the even smaller volume of the Voron 0 to be sufficient for almost all of my printing for years now, and I will still have the Prusa for larger objects.

I have a few nice linear rails and a spare Duet 3 board. Of course, that means that I have to make a new coreXY printer to complement my Prusa Mk4 and Duet-powered Voron 0.

The rails are long 15mm THK with a light preload, and a couple of short 9mm THK. All are second hand but only lightly used.

It seems to me that I have enough rail to make a printer with about 150mm x-axis travel and 250mm y-axis travel. Are there any problems or gotchas associated with a non-square printer?