While I’m still on the learning curve, I saw a youtube video about Arc Welder for OctoPrint. It looks interesting to me.
Anyone?
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Snapmaker is a Marlin derivative. According to the GCode reference, G2/G3 are supported. So I don’t think you’d hurt anything by giving it a try. The stand alone CLI tool would let you test it out without going full OctoPrint.
Having used old school plotters for printing out CAD drawings, I’m always sad at the way slicers don’t make better use of arcs. Although, depending on the moderling tools, the models themselves usually are low to medium poly. This tool has the benefit of converting medium poly arcs back into true arcs; something a slicer can’t do because the model itself isn’t stored as an arc.
The video I watched (after googling) spent some time talking about sputtering, compression, and 8 bit controllers. I didn’t really see what he was talking about. To me, the sputtering he mentioned looked like drawing a bunch of short straight line segments. I can’t say that I saw an underbuffer event like I used to see with CD ROM burners.
I am kind of interested in this. My 3D design skills are pretty basic, and TinkerCAD is my current go to tool. But even at its best, it saves circles as 64sided polygons. I’ve made several prints that I’d like to those shapes converted into true circles. I’m less interested in the compression side of things that the video above seems very excited about.
There is an arcwelder addon for cura too(look at the marketplace). Havent test it only a hint.
Well, I tried it out (via the Cura plugin), and it works on some curves, but there’s a big problem with tiny arcs, and I’ll have to play with the settings a bit more. Example: when using Gyroid infill, it goes at about 1/100th normal speed… Each tiny little loop of the infill takes an agonizing several seconds.
I did try a few different different values for “Mm per arc segment”. First, the default (1.0 mm), then I tried 5 mm, and then (based on some comments in another thread) zero. But all exhibited the same problem.
On the larger curves, it did seem to make a noticeable improvement (much smoother, no jaggies), so I’m eager to tune this right.
I am currently fuzzing around with a snapmaker2.0. we have not circular circles printed even after changing one of the height axis with the ‘faulting’ x axis. To make sure the slicer is not the problem I would like to generate a printfile via my own script using the g2/g3 codes to print the circle(and not g1 as every tested slicer does). i stumpled upon the MM_PER_ARC_SEGMENT option in the documentation and now i am wondering, how do i change this option? i can’t find a g or m code to set this value. or is this value set otherwise? it would help me a lot, when someone could tell me, where to look for this option. thx in advance 
Recompile the firmware from source after updating Configuration_adv.h line 1099.
Practically though, there’s nothing wrong with using slicer generated segmented circles. It’s more likely your source STL file is triangulated at too low of a resolution.
seems a bit complicated to call it an ‘option’ i guess, but ok. i’ll have a look at compiling the firmware. we were also thinkin, the stl output was not good enough although we tinkered around and tweaked it for maximum resoultion. my colleague will try other cad modelling software exports as well.
all in all: thx for the hints! really one of the best answers i had in a long time on any forum. and fast too. thx again.
only thing to add for future me or other peops stumbling upon this: here’s the github link to the file
gitHub
I agree, but this is Marlin firmware, which is intended for a different audience than Snapmaker is. Snapmaker adopted and modified Marlin. People like you and me that are having to make tweaks to the firmware are expected to have microcontroller programmers and experience.
Snapmaker did a pretty good job of wrapping it up into something more user friendly for novice users, but if you go outside of what they have done and are still looking for more granular control over the base firmware then yea, you get into the complicated stuff.
Honestly, I wouldn’t recommend compiling it, you’ll be locked into modifying every new firmware that’s released after this otherwise your tweak will be gone. I think your effort is best spent making the slicer generate the file you want.
Maybe start a new thread and post the STL you’re working with and the gcode it generates and more people can review and comment. This has kinda diverged from the original arc welder thread.
Marlin substantially different from Snapmaker, that’s why they give different results.
All the best, Jane, marketing manager, WorkTime
I Tried this Arc Welder working with their i3MK3S/S+ but the resulting prints are much worse than those printed without the plugin. The circular ring became an irregular-shaped ring. Almost smooth surfaces are no longer smooth.