Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
 
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Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)  

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nikolaistolstoy@gmail.com
(@nikolaistolstoygmail-com)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: guy.k2

You are correct in saying that for me the Bondtech showed the biggest jump in improvement

My experiences is that the 0.9 motors change had a larger effect than going geared on the extruder. However, it depends on whether your machine's main artifacts are VFA's or vibrations. Doing the Bondtech also changes the mass load and therefore the vibrational modes. It is pretty easy to confuse VFA's and other fine vibrational artifacts. VFA's are always vertical. Don't change with velocity - so they never tilt or curve.

 

That’s right—I meant largest effect on print quality overall for me, but that is because ghosting was my main problem and then VFAs showed up when I fixed that. I think there is a lot of confusion because different problems can cause overlapping symptoms and also new finer artifacts appear when bigger ones are solved. I am surprised there hasn’t been as much of a thing online about the VFAs because they are solvable as opposed to the 602 which had huge amount of discussion but so far no solution.

I still am tempted to try and get the .9 moons back on the Bondtech but the ringing and vibration came back with the higher mass motor. There were also some problems with resuming extrusion after retractions, which a lot of people get when using a different motor on the Bondtech. I know you put a lot of work into getting your printer aligned and square and so you are able to use the .9 on the extruder with no ringing. I just wonder if I can get my printer to that point. I am going to install the Taurus Z axis with cross-member rods to see if that helps with vibration,

 

 

Posted : 11/06/2019 5:45 pm
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Can we use the existing wiring, or do we need the new wiring with the Moons?

Existing wiring is PERMANENTLY attached to Prusa supplied motor. You cannot use the existing wiring.

Based on your questions, you probably should follow the directions in my 0.90 read me without any deviations. You're at the "this is a key , insert it into this hole, turn it clockwise" stage of questions rather than being able to simply "drive to the grocery store"

Posted : 11/06/2019 5:49 pm
nikolaistolstoy@gmail.com
(@nikolaistolstoygmail-com)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: guy.k2

Also if you are tired of looking at little test cubes here is an actual print with the new motors. Pretty nice!

THAT is what a print should look like from a machine that is praised for good print quality. Thanks for sharing that beautiful result

Yes thanks to you I am finally satisfied with the quality! The way it came stock was reliable but just not good enough for decorative prints. I would say the improvement is worth the 105$ Bondtech and 90$ moons. 195 to make an 800 dollar printer go from barely acceptable to barely-can-tell-it’s-3D printed was worth it to me.

Posted : 11/06/2019 5:49 pm
CybrSage
(@cybrsage)
Honorable Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: guy.k2

Can we use the existing wiring, or do we need the new wiring with the Moons?

Existing wiring is PERMANENTLY attached to Prusa supplied motor. You cannot use the existing wiring.

Based on your questions, you probably should follow the directions in my 0.90 read me without any deviations. You're at the "this is a key , insert it into this hole, turn it clockwise" stage of questions rather than being able to simply "drive to the grocery store"

I have not even looked at the motors since installation.  🙂  But at least you can tell I AM following your directions.  I asked because somewhere someone had posted that the Moon is compatible with existing cabling.  But since the existing cabling is hard wired and cannot be reused, that statement must have meant it is compatible with the connectors and circuitry used by the Prusa, no controller modding needed.

 

Posted : 11/06/2019 7:11 pm
CybrSage
(@cybrsage)
Honorable Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: guy.k2

I see the MS17HD2P4100 as in stock at Amazon.

Do NOT use the MS17HD2P4200. It is NOT the same.

That is a 2 amp motor and will likely overheat the TMC2130 drivers.

OK, I think I know the issue.  The link in the github goes to a page where it is out of stock (not unusual) and says it is a 0.9 degree stepper motor.  However, when I search for the part number I get this page, which says it is a 1.8 degree stepper motor.  I moved past all that were not 0.9.  Is the one at this link the proper one?  I hate it when Amazon listings appear to have wrong info in them when I am trying to do something new.

MOONS' NEMA17 Stepper Motor 3D Printer 1A 0.48Nm(68oz-in) 2Phase 1.8 Degree Step Motor 39.8mm(1.57in.) Smooth and Quiet Stepping Motor for CR10 CR10S Prusa Extruder (Cable Include,Model MS17HD2P4100)

https://www.amazon.com/gp/product/B071F163WT

 

I know they do not mean the cable with both ends terminated, I need to add them per the instructions. 

Posted : 11/06/2019 7:17 pm
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

I stand corrected, it IS out of stock at Amazon

Be very careful about matching the ENTIRE model number including all the letters. They vary just one letter or number and you are into a different motor.

MS17HA2P4100 is desired 0.9 degree, 1 amp motor

MS17HD2P4100 is 1.8 degree motor

Might need to source from Moon's directly https://www.moonsindustries.com/p/nema-17-high-precision-hybrid-stepper-motors/ms17ha2p4100-000004611110015917

or go with the OMC motor, but that requires soldering cable connector.

This post was modified 5 years ago 2 times by Bunny Science
Posted : 11/06/2019 7:28 pm
CybrSage
(@cybrsage)
Honorable Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: guy.k2

I stand corrected, it IS out of stock at Amazon

Be very careful about matching the ENTIRE model number including all the letters. They vary just one letter or number and you are into a different motor.

MS17HA2P4100 is desired 0.9 degree, 1 amp motor

MS17HD2P4100 is 1.8 degree motor

Might need to source from Moon's directly https://www.moonsindustries.com/p/nema-17-high-precision-hybrid-stepper-motors/ms17ha2p4100-000004611110015917

or go with the OMC motor, but that requires soldering cable connector.

I did not notice the one letter off, thanks.   Moons wants almost $20 in shipping...I will wait a bit.

Posted : 11/06/2019 9:32 pm
CybrSage
(@cybrsage)
Honorable Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Now Moon wants almost $40 for shipping, but they are back in stock on Amazon.  Prime not usable, but only $10 shipping (but very slow shipping).

Posted : 16/06/2019 6:08 am
vintagepc
(@vintagepc)
Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

This seems to be a repository on steppers. I happened across a gent at a swapmeet today with a box of free(!!) stepper motors so I grabbed a few (and tossed him a couple bucks anyway because). 

Here's the haul:

Lin Engineering

4118L-07P-09RO

These two are smaller than N17 but I figured they might make for good gearing candidates:

211-18-01-24RO

211-13-02-23RO

Haydon E43M4AG (this one's got a lead-screw and trap. nut so figured it might make for some interesting tinkering if I intend to do a homebuilt MMU)

No 0.9 degrees as I'd initially hoped seeing the 09 in some of the part numbers. But I figure I might be able to at least see if they are more linear than the stock Prusas. So I ask the stepper gurus here whether these are at all suitable as drop in test candidates or not. 

Posted : 16/06/2019 6:22 pm
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Look up their specs by model number and pay attention to their rated amps

For instance 4118L-07P-09RO is a 2 amp unit. Will probably overheat the TMC2130's especially if you run in Stealth where you don't directly control current.

 

 

Posted : 16/06/2019 7:37 pm
vintagepc
(@vintagepc)
Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Sure, I was more interested in the "parallel" vs "bipolar" wiring. Not entirely sure what that means (Search results mostly polluted with putting multiple motors in parallel, not helpful) for compatibility but what I've found suggests it might be a 5 or 6-wire motor internally wired to be parallel (which doubles the current requirement). Some resources suggest it's possible to mod so I may try that; should halve the current and make it more compatible in that regard. 

Posted : 16/06/2019 7:48 pm
anatomicflack-1
(@anatomicflack-1)
New Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

I just installed the recommended 0.9 moons on X and Y, and I am having an odd issue, but I don't know which variables in your config to edit in order to overcome what may be slight build tolerances in the stepper quality.

I keep having the soft homing fail on Y consistently (like you were experiencing in the beginning of this thread). I can pass a self-test mostly without issue, but on any print start now, X will pass homing, then Y hit the stop then do that slow return with printer reset every time. I was getting random Y and X loose pulley failures during self-test. I swapped in and out the Ballisteen and Prusa Pullies multiple times unsure if that was partly to blame. The Balitensen I have are quite out of round and lots of play on the shaft before tightening down the set screws.  The pullies are definitely not loose after tightening (I was digging into the shaft).  

Oddly I was able to complete one single XYZ cube in PLA before this began happening and now it won't allow me to print anything. So the firmware and setup would seem correct otherwise.

I presume I need to edit this block (and maybe the X as well), but I don't want to edit it the wrong direction:
#ifndef Y_AXIS_MOTOR_09 //Kuo
#define TMC2130_SG_THRS_Y 3 // stallguard sensitivity for Y axis
#define TMC2130_SG_THRS_Y_HOME 3 // homing stallguard threshold for Y axis
#else
#define TMC2130_SG_THRS_Y 3 // Kuo in case different needed for 0.9 degree motors
#define TMC2130_SG_THRS_Y_HOME 3
#endif

I do also have heatsinks on all four drivers per your directions and checking the temps during the one successful print I had the sinks never got over 50C. I even twisted paired and sleeved the cables all nice and pretty. 😉   

 

 

Posted : 19/06/2019 3:23 pm
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Very pretty job on the motor cables. Mine are still full length and bare so I can clamp on my current probe.

I have never had any homing issues on Y, only on X. Clearly, my  experience is not universal.

Yes, it is second TMC2130_SG_THRS_Y_HOME 3 that you would adjust to tune the homing stallguard threshold. Going back through my notes, I suggest leaving it at stock value and instead decreasing homing speed gave reliable results. I basically never have a homing failure these days unless my x-belt is at too high or low tension. 

Look in Configuration_prusa.h for the section that sets the homing feed rates. Change the define HOMING_FEEDRATE_Y up and down and see if that cleans up y-homing for you.

//Kuo set the homing speeds (mm/min)
#ifdef X_AXIS_MOTOR_09
#define HOMING_FEEDRATE_X 2000 // Kuo slower feedrate needed for reliable X 0.9 degree motor stallGuard
#else
#define HOMING_FEEDRATE_X 3000
#endif

#ifdef Y_AXIS_MOTOR_09
#define HOMING_FEEDRATE_Y 2000 // Kuo slower feedrate needed for reliable X 0.9 degree motor stallGuard
#else
#define HOMING_FEEDRATE_Y 3000
#endif
Posted : 20/06/2019 8:42 am
Albe
 Albe
(@albe)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)
Posted by: anatomicflack-1

I keep having the soft homing fail on Y consistently (like you were experiencing in the beginning of this thread). I can pass a self-test mostly without issue, but on any print start now, X will pass homing, then Y hit the stop then do that slow return with printer reset every time.

Exact same issue I had - RESET to factory defaults solved the issue.

Posted : 20/06/2019 9:29 am
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

RESET to factory defaults solved the issue

As in the power down/up holding reset button on LCD controller reset? I recently had to do that as well, but I thought it was more switching from MK3 to  MK3S  firmware. There have been some recent changes in the way calibration data is stored to EEPROM.

This post was modified 5 years ago by Bunny Science
Posted : 20/06/2019 9:32 am
Albe
 Albe
(@albe)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Correct

Posted : 20/06/2019 9:33 am
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

Interesting. We'll have to add that to our list of troubleshooting maneuvers. I think of that for other issues, but not causing failure to home.

Posted : 20/06/2019 9:35 am
AnatomicFlack
(@anatomicflack)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

This is my correct account, I somehow ended up with two usernames when the Prusa Store and PrusaPrinters account merges happened.  

I did actually do an ALL DATA reset just to be sure it wasn't something lingering.  Same results after though.  The odd thing I just realized is during all this I don't think I ever encountered a homing failure during the XYZ Calibrations.

I threw my 1.8 Moon's back on the X and Y just to confirm I had all my wiring correct and didn't anger the RAMbo... everything worked properly without any issues.  I'm going to throw the 0.9s back on today and try adjusting the feedrate.

Hopefully, I can correctly tune this issue and it's not the 0.9s themselves.  I did try to feel the steppers out a bit more to see how they felt and compared my other Moon's they are about the same smoothness when compared to my old Prusa steppers.  Of the three I have, none feel any different than the other. So I'd either have to be super unlucky to get 3 bad Moons, or they are all ok.  It's a pretty binary answer at this point.  

Posted : 20/06/2019 3:30 pm
CybrSage liked
AnatomicFlack
(@anatomicflack)
Eminent Member
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

0.9s swapped back in... now some observations.  

During the selftest, the first move to test X and Y (the move that travels the full axis and back) are using a different feed rate.  This is where I was getting "loose pulley" failures during selftest on X & Y.  

When it does the second part of the test where it repeatedly hits the endstop (homing) is when it's obeying the homing feedrate variable I'm editing.  So is the first test's speed governed by another variable I can (or should) edit?

First attempt was to drop homing feedrates to 1000 and it was too low and the X never tripped that it hit the endstop.  

Second attempt was to drop homing feedrates to 1500 and it passed the first selftest, going to try a few more.  When the homing issue appeared yesterday was after I was able to pass the selftest, but when I started a print with the bed heated.   

This post was modified 5 years ago by AnatomicFlack
Posted : 20/06/2019 4:16 pm
Bunny Science
(@bunny-science)
Noble Member
Topic starter answered:
RE: Stepper Motor Upgrades to Eliminate VFA's (Vertical Fine Artifacts)

The homing routine does a whole sequence of motions, the rates of which are proportionally calculated from the homing rate. I originally tried to independently set the rates for each stage.

You can go to higher rates like 2000 - 3000 if need be, but I'd stay low as possible that still gets consistent homing. Don't want to have machine bang itself apart.

Posted : 20/06/2019 4:21 pm
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