Layer shifts at high speeds on VC3-400
Hi everyone,
wondering what the usual max speeds / accels are on a VC3 400 on 24V. I'm running into layer shifts at 35000 mm/s² and 300 mm/s infills.
I'm using the official kits with the LDO motors.
run_current is set to 1.768 A
18 Replies
This should indeed be possible, maybe belts are too tight?
Last i tried maxing out 24V i got to 45k @ 350 mm/s
absent-sapphire•12mo ago
That's... a lot 😄
Well it can do 35k and 350mm/s
but not while printing
/extruding
The belts are tightened so they just don't smack the extrusions
so more on the loose side of things i'd say
Hmm
absent-sapphire•12mo ago
I mean.. it has a drag chain mounted to it, so that may reduce possible accelerations somewhat. IIRC, you had your's with chain but went back to an umbillical, didn't you?
i did yeah
the 45k was with the drag chain
And even a heavy BMG
This was on 24v https://www.youtube.com/watch?v=foChudbKy60
EVA-3D
YouTube
400mm Rat Rig V-Core 3 #speedboat!
5:27 #speedboat done on the 400mm Rat Rig V-Core 3.
Hotend: Nitram's #volcomosq
Extruder: Bondtech BMG
Cooling: Delta Electronics PFB0412EN-E at 80% PWM
Mechanics and electronics are stock except for the addition of a bottom panel, which i doubt makes any difference.
Firmware: V-CoreOS (Klipper) https://rat-rig.github.io/V-CoreOS
Acceleration:...
Acceleration: 42000 mm/s^2
Accel to Decel: 21000 mm/s^2
Square Corner Velocity: 80
absent-sapphire•12mo ago
Hm, I had it on accel to decel 35k as well
That does make a difference
absent-sapphire•12mo ago
and 15 sqv
So it’s probably breaking quite hard on those moves
80 is a whole lot worse
It basically means "you can make a 90 degree turn at this speed"
absent-sapphire•12mo ago
hmkay
makes sense 😄
But try half accel_to_decel
that should help
absent-sapphire•12mo ago
i'll try that.
any tips on efficiently finding your max accel?
printing and just upping it in the ui?
I don't have it anymore but i made a gcode macro that looped through a bunch of long moves and very short moves a bunch of times. Then i just ran that at higher and higher accels until it started skipping. Then i started increasing the speed until it started skipping.
You wan't both X/Y and diagonal moves of course
That works too, just a bit more messy 😄
absent-sapphire•12mo ago
do I really want combined x/y moves? shouldn't diagonal moves that only stress one motor at a time be the weakpoint?
It's a bit complicated because Y for example is moving a lot more mass. But X shouldn't matter.
absent-sapphire•12mo ago
ah
That did the trick 