RC7 is making my machine shake badly with some “fast” test files I use, acceleration changes doesn’t seem to fix it even though that’s usually the issue (laser cutting needs faster acceleration than, say, routing - burning continues, routing doesn’t.) I’m sure they’ve tested it with 3D printing, which I have not yet, but I’m pretty concerned about the differences I’ve seen so far.
Yep, I usually have it set to 12 but I just tried 4 and it’s the same deal.
This particular gcode file (Inkscape generated) just sends the tool around in a big circle (almost the full size of the machine 70cmx70cm) as fast as it can go. I’ve tried it successfully on both the old Marlin and GRBL. It’s pretty smooth.
It looks like (on the lower Jerk setting anyway) it’s stalling at the end of each arc. segment.
It’s entirely possible I’ve screwed up a setting for my machine, since it’s a little bit custom, but straight moves seem OK.
Does the following gcode produce a totally smooth circle motion for you guys? (after the initial movement of course, and this should “fit” on any machine):
(Header)
(Header end.)
G21 (All units in mm)
(Start cutting path id: path3336)
(Change tool to Default tool)
OK, thanks for the suggestion, but it is interesting to note it’s now much worse with the newer firmware. Marlin is meant to be able to process arcs, though the old version did sometimes stutter once on some runs of the “big” circle, the new one stutters at every arc-end. Probably too many things happening and buffers emptying causing stalls. But it’s a trade off, really, by turning off arcs you end up with lots of code for only relatively small machine movement. This can have its problems too.
I might stick to GRBL for everything except 3D printing. It runs both the little and big circle tests smoothly and it’s very consistent. Marlin is new to me, I usually use Sailfish and/or GRBL. Thanks again.
There is an arc tuning setting in config adv.h of the new firmware that I have not set. I can try and look into it. But I think marlin does much better without using arcs, downside is a slightly larger gcode file.
It’s a hard question to answer, if you should look into it or not. I’ve had a play now and the old Marlin seems slightly better with 2mm per arc. instead of 1mm, and the new Marlin seems better when set to 4mm. I have not connected my pen up to see what 3mm-Diameter circles look like (which is something I would cut often for screw holes) but if they turn out round enough I’d say go with those settings. Alternatively, if you do see what I’m seeing (which no-one has confirmed yet, to my very slight disappointment) then a report to the Marlin programmers might be an idea. At least I know my mods. to Marlin are showing the same issues as your new firmware release, so thanks again!
It is actually pretty easy which is why it has become so popular and why I recommend it. When on the main Marlin page you can just click the fork button and you can have your fork of Marlin where you can make your changes, updating it to keep in sync with the mainline is easy and any conflicting changes that you have made are also easier to spot. There really isn’t much more to screw up than your current releases as your changes are kept separate from mainline Marlin unless you really do have a fix that you want them to have that isn’t MPCNC specific.
Cool. I’ll take a look and if I get stuck I’ll come to you. It does sound like a good idea, I will still have to have a download available here, I got a ton of questions when the laser software was on github, no one knows to download the zip file. Maybe I can just link it…I’ll check it out.