RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
patchset
I can barely make GitHub work let alone create a patchset. Making things worse, is that several nature sets (LA 15, Skelestruder lengths, Slice thermistor) are not actually my work. While I can competently add my patches, the other stuff I'd never be quite certain I got all the changes.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
patchset
I can barely make GitHub work let alone create a patchset. Making things worse, is that several nature sets (LA 15, Skelestruder lengths, Slice thermistor) are not actually my work. While I can competently add my patches, the other stuff I'd never be quite certain I got all the changes.
Ideally you'd split those out as more patchsets. Instead of having them in your code as defines, an user would apply these patches as needed. This would also aid code readability and simplify your maintenance efforts 🙂
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
That sounds great, but where does one learn how to create and maintain patchsets?
It is easy for our (barely able to compile firmware on Arduino) users to apply patchsets?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
If I were in your shoes, I'd do it like this:
- Start over with a fresh Prusa firmware git repo on the MK3 branch.
- Create a new branch based on it, call it "0.9_steppers" or something like that, merge all the changes relevant to making 0.9 steppers work into it.
- Create another separate branch based on MK3 (not 0.9_steppers!), call it "LA_1.5", merge all things related to Linear Advance 1.5 into it
- Repeat for all features you have in store
These are called feature branches and help keep the changes separate and organized. Just make sure to always be in the correct branch before committing.
Now others can either check out this repo directly (if they know git) and merge all the branches they want into their working tree. Or you can have git create diffs (diff = patch) between MK3 and a feature branch, thus creating the aforementioned patches/patchsets, which can be merged onto the stock firmware sources.
As for users being able to apply patches, it could be tricky, but I think Github makes the process somewhat easier. I know it doesn't sound as nice as just uncommenting a define, but keeping your repo organized this way is worth it in the long run, trust me.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Looks like I don't get the 0.9 motors reliable to work 🙁
Printed many things successfully but yesterday, after printing for 10h or so a massive layer shift randomly occurred on the x axis. I printed in stealth mode.
Mechanical caused layer shifts are usually small (some mm) but not this far. I don't understand the science behind electro-technics well enough but it looks like the board/stepper just skipped a whole bunch of steps.
To rule out the hardware (x axis): grub screw is tight, belt is well aligned and not touching the grub screw sides, idler spins freely, back plate of the bear extruder is not too tight and homing is reliable from bottom to top, belt tension also feels right.
Any ideas?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Looks like I don't get the 0.9 motors reliable to work 🙁
Printed many things successfully but yesterday, after printing for 10h or so a massive layer shift randomly occurred on the x axis. I printed in stealth mode.
Mechanical caused layer shifts are usually small (some mm) but not this far. I don't understand the science behind electro-technics well enough but it looks like the board/stepper just skipped a whole bunch of steps.
To rule out the hardware (x axis): grub screw is tight, belt is well aligned and not touching the grub screw sides, idler spins freely, back plate of the bear extruder is not too tight and homing is reliable from bottom to top, belt tension also feels right.
Any ideas?
do you have a mk3 or a 3s?
if the former, is your filament sensor enabled? false readings can cause massive layer shifts:
https://github.com/prusa3d/Prusa-Firmware/issues/1522
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It is enabled but the print didn't stop and asked for "remove filamament". This is the normal procedure after the sensor is triggered.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
It is enabled but the print didn't stop and asked for "remove filamament". This is the normal procedure after the sensor is triggered.
Humor me, disable it and try your print again. False trips don't prompt for a change when it determines all is well (it flags a runout, double checks and determines there is still filament), but can mess up the planner buffer and the printer will wander off into no-man's land as in the github issue.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Worth a try. I'll report back. After 2-3 successful (bigger) prints it's odd that it is happening now.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Not really, I had the same issue where it was fine for a while and then gave me no end of grief. Note it may not be noticeable if it happens in an area with a lot of small direction changes; it tends to be more visible if it happens in something with long straight extrusions like solid or line-type infills.
It's also highly filament dependent too.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Knock on wood but I may have found the cause of my crashes. I derped and had the Y motor cable mounted in such a way that it could rub on the Y carriage. Relocated it, time will tell.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Nope. Didnt't knock hard enough. But M350 will be fixed in the next release for X/Y, so if it continues happening I can actually test in stock without needing to recompile.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
VintagePC, are you running the latest rev of my fimrware. I readjusted the y axis stallguard threshold about a week ago to match the x-axis. It is a bit ess sensitive now.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Good catch, that came in after I'd merged down in prep for the mk3s skelestruder tweaks (PR filed on those)
I'll pull down and rebuild.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Not really, I had the same issue where it was fine for a while and then gave me no end of grief. Note it may not be noticeable if it happens in an area with a lot of small direction changes; it tends to be more visible if it happens in something with long straight extrusions like solid or line-type infills.
It's also highly filament dependent too.
I gave it a try and it shifted again after about 10h. This time it shifted to the left and not to the right and some layers earlier. Filament sensor was off and I didn't really suspect it to be the trigger for the problem. The MK3S filament sensor isn't really filament dependent but only if the diameter of the filament goes below 1mm or so but then it would be time to stop the print anyway ^^
Is there any way to debug this problem? A Duet 2 is already in my shopping cart but I so very much like this setup to work as a 2nd printer 🙁
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Benbee, this is almost certainly a mechanical issue with the x-axis rod and bearing system. There are two ways around it.
1. Temporarily change the machine to standard (high power) mode instead of Stealth. This gives you more motor torque to overcome the mechanical problem until you actually solve it. However, VFA's are typically more visible in spread cycle than stealth chop. So, print quality won't be quite as good. That should let you print out something for the more definitive solution.
2. Upgrade the x-carriage with the newest revision BNB Universal X-carriage v BNB9S. The new version gymbals the x-bearings so they self-align during installation. This improved carriage design fixed a x-axis shift that vexed me on one machine until the new x-carriage design. Like you, I thought the existing x axis bearing setup was running smoothly, but the x layer shifts were proof x-axis was presenting the 0.9 motor with too much mechanical resistance during fast, n0n-print moves.
https://www.thingiverse.com/thing:3610593
(You should individually download the files because "download all" is not entirely reliable about grabbing more recent files on Thingiverse)
I would definitely clean and re-lubricate the x-bearings while you have things apart to upgrade the x-carriage.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Thank you. I'll try that too.
I just lubricated all my bearings some weeks ago whilst upgrading to the bear X-axis. The x-carriage also runs very smooth without the belt.
I also think it has to do with the available torque. As the print goes higher the cables attached to the X-carriage might increase the resistance the motor has to overcome.
Speaking of torque. I thought the M906 is to set the motor current in mA but I don't think it is used with the Prusa FW? What I found is:
#define TMC2130_CURRENTS_R {16, 20, 35, 30} // default running currents for all axes
But how does this translate to mA?.
The coolers on the backside of the EINSY / TMCs are max 50°C hot. So I think there would be some headroom for higher mA.
Motors for both axes are also not really hot.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
#define TMC2130_CURRENTS_R {16, 20, 35, 30} // default running currents for all axes
That is for spread cycle and yes x is set lower by Prusa. Stealthchop semi-automatically sets motor currents independent of the above current paramters. I can't readily recall which settings were involved in Stealthchop. Would have to dig through some old notes.
I would first focus on the mechanicals rather than boosting currents. The 0.9's do have less total torque, but if the mechanicals are good, they should be adequate. I simply don't have layer shifts once my axes are sorted. Seriously please do upgrade to the new x-carriage. It is considerably lower resistance axis motion.
With regard to the extruder cable bundle, reduce the wrap rotations around the extruder cable bundle so you maximize its length. There should be just enough nylon sticking beyond wrap to engage 1-2 cm into the nylon fiber mounting hole in the EINSY case.
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
No worries, I'm already printing the X-carriage =)
But still, I'm wondering why you didn't increase the currents to increase the reliability with 0.9 motors.
Even the filament spool could give some resistance in the wrong moment and thereby cause a layer shift when there is no headroom available.
Did you have a specific reason for that?
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
why you didn't increase the currents to increase the reliability with 0.9 motors
During early testing of 0.9 motors I ran into TMC overheat situations after several hours of printing. That is why I have heatsinks on all my EINSY boards at the TMC2130 driver heat vias. For me, that indicated currents were pushing thermal limits especially when in Stealth mode where the system self tunes current. Because Stealth produces the best looking prints on my printers, I stay in stealth.
I have had zero issues with layer shifts on my printers except for some recent polycarbonate x-carriages that held bearings too tightly putting them out of alignment. That spurred the new x-carriage design which lets the bearings find their own orientation even when printed in stiff materials.
I basically don't see layer shifts even on 24 hour long prints. No shifts = no need to boost current. No need + EINSY already near current limits = I don't try to boost the current.
Only thing that might be a difference is my bearings and rods are Misumi rather than stock Prusa.