@dwuk said in Sovol SV08 Multiple Motion System Upgrade.:
I would only use Z for layer changes, with all other Zhops and mesh adjustments being done independently with the B and C Zhopper axis.
That's what I proposed to implement in RRF while I played with the hashPrinter.
I wonder if it's possible to use G10/G11 for FW-retraction with zHop in your case? You'd have to link it with your BbCc motors. @dc42 ?
@dwuk said in Sovol SV08 Multiple Motion System Upgrade.:
I will have to split each long move into segments the size of the grid.
IMO, that won't be that easy. Mesh adjustment is continuous between grid points.
And for tool No2 you'd have to know where tool No1 is to compensate No2's adjustment accordingly.
@dwuk Still looking good for a first attempt. I guess you had mesh levelling off?
Maybe try to dial in each toolhead independently with unaltered single-head gcode. When both work OK on their own, let them cooperate.
@dwuk Backlash won't be your primary problem when you use the "outer perimeter in one go" version of your gcode postprocessor.
I wouldn't spend too much time on it now and try to make a working proof of concept first.
You might have to redesign alot anyway, just put it on your ToDo list.
@Ce72 said in Like Z Banding:
NTC 100K thermistor on there heaters which from what I understand can be a pain to setup and not that great for the higher temps.
Bed temps are pretty low compared to extruder temps. I don't see a problem here?
Whenever a NTC failed on me, it was a lousy crimpjob or broken thermistor leg from too much motion.
@bernardomattiucci I think, the onchip memory hinders the FW to store a finer/bigger map and moving the whole data to the SD-card would lead to constant reading from SD and might cause failure.
Having a few small (slightly overlapping) maps stored on SD and loading only the next relevant map would probably work, but it'd take some postprocessing of the gcode file, I guess.
Because daemon.g wouldn't be able to look ahead far enough to do that while printing...
@Notepad said in Like Z Banding:
Its weird that the woodgrain test appears to be normal and and then your next two prints have this weird artefact.
IMHO, the difference is vase mode versus solid. Might be related to PA-settings? They don't apply in vase mode...
@dwuk Those motors are nice findings...but the small one might be too slow for anything? (15-20PPS @18degree/step divided by 100/1 gearbox) If my math is correct, it'll take 50 seconds for half a turn (outputshaft acting like hobby servo excenter)
You will also need a way to fix the tool in both directions. Otherwise the extruded filament will push it up.
@dwuk said in Sovol SV08 Multiple Motion System Upgrade.:
Not sure why the adjustments are so large
It's just the difference between the configurated tool offset and trigger point of the probe.
Since they are all pretty close (-0.4ish), your bed level looks fine.
@53581 That'll do, but it's a bit overkill.
@ralph-malan said in Closed loop with linear scale:
Is it not commonly done?
IMHO, if a system needs closed loop control it isn't engineered well. Steppers shouldn't lose steps under normal conditions.
But in your case it's about saving money, but still get good results. I hope it pays out.
@dwuk One point of concern is the tiny screw that connects the excenter with the servo. It has to hold the whole weight of the tool?
There is also a big distance between tool-COG and the anchor point of the excenter, which adds the tendency to tilt the extruder rather than lift it. (risk of racking?)
I just thought: worm gear! The smallest motor will be able to lift the tool and it comes with inbuild self locking.
Location Smith Mountain Lake, VA, USA
Thought I'd add your home base for easier postage fee calculations.
@ralph-malan AFAIK you can use a linear scale as secondary device, but the closed loop sensor has to fixed to the motor shaft.
There is also a static definition for backlash compensation, but IDK if it works for closed loop or just adds some extra steps everytime the motor direction changes...
@dwuk said in Sovol SV08 Multiple Motion System Upgrade.:
add a bearing to the cam
That's what I meant before when I said use excenter bearings. Three of them in a planetary gear fashion could also replace the mgn-linear guide and have a wider footprint.
I'm not good with CAD or napkin drawings, otherwise I'd sketch up an example. Probably best suited for a pancake stepper.
@53581 said in diagonal line on print causing layer shifting?:
a add linear bearings for the blue lines and then somehow mount the linear bearing cars to the x in a way that it can pivot so it can move independently.
To avoid axis' binding, you need to fix one side while the other side can "float" in one direction to compensate thermal expansion.
The Ender 3 runs on v-rollers. You might have a flat spot on a roller or some dirt collection on the rails?
If it was real level shifting, you'd also see it on the inside, but it looks OK there.
@enewman26 I started tinkering with a plasma torch a while ago. Control-wise it's easier for a regular Duet. Even an old Duet 2 can do it.
A heavy-duty CNC mill will need a Duet 3 with external drivers, I guess.
Ballscrews is the way to go IMHO (low friction and high speed for plasma cutting)
@dwuk said in Sovol SV08 Multiple Motion System Upgrade.:
I think I will try putting them at the front
"Goodby toolchanger" then? Isn't there a way to distribute the steppers to the left and right, keeping the front available for extra tools? Steppers aren't exactly lightweight and you'll need some beefy motors to overcome the friction of the idler pulley-orgy.
I mentioned it before, but my hashPrinter only needed 4 motors for 4 semi-independent toolheads. The super simple gantry was the reason why I built it.
@dwuk One thing I noticed in an earlier picture was some scratching belts:
I thought it was just temporary, but it still seems a problem.