Trying to increasing print surface quality (E3D on Flashforge?)

I have printed a lot in layer heights of 0.1[mm] and low speeds (25~50) and noticed that my prints had a 'wavy' pattern in the vertical direction.

This could have several causes:
- 'loose' X & Y belts; (tried tightening, still appeared on straight lines)
- mechanical jerking (tried changing acceleration settings and lowering print speeds overal - resulting in less waves at corners, but still present on straight lines)
- uneven filament (measured my filament at several places with my Mitutoyo, seemed to be good)
- uneven heating of filament (temps on Flashforge appear to be very constant, no real way of checking the output - could conduct a test with extruding at a MUCH higher temp than I usually use)
- damage / junk in nozzle (does not appear to be the case)
- nozzle size too large for amount of extruded filament (this could only be tested by using a smaller nozzle)
- general vibrations
- printing too fast for extruder steppers (not the case)
- printing too slow for extruder steppers (uneven extrusion due to low speed)
- feeding gear is damaged / too little teeth

This last one got me intrigued so I tried printing as usual but moving the bed way downwards (printing in the air) and noticed that the extrusion was a bit 'wavy' by itself: (thick - thin -thick - thin - thick - ...)

This is probably the issue I'm looking at, so that means it has to be one of these causes:
- uneven filament
- uneven heating of filament
- general vibrations
- printing too slow for extruder steppers
- feeding gear is damaged / too little teeth

As mentioned, I've already conducted some tests for the above, but will redo them a bit more serious now that I've narrowed down the cause (which hopefully is really is the cause!!)
Another thing to note here is that the wavy pattern on the final product (a cube for testing purposes) is very consistent with its location. This already rules out the 'uneven filament' because that would mean that it should be more 'random'. But since the extruder starts doing the same thing EVERY layer, it has to be one of the causes listed in bold above.
General vibrations I have already minimized as much as possible.. but this is more of the final cause if everything else fails (which means that that would be the limit of the surface quality.)

Uneven heating I will test by heating the filament MORE, why? Uneven heating could be a problem if different parts of the filament are in different 'phase' stages, if I heat everything way more then it should all be in the molten phase I'm looking for.

The 'printing too slow' is a bit more difficult to check, because yes; this doesn't happen at faster feed rates, but I want to be able to extrude with these layer thicknesses.
So I was thinking to get a bowden setup here, then running the motor 10 times as fast (in software), and using a gear (10:1) to allow the feed rate to be correct. This way any 'steps' of the stepper motor shouldn't be visible anymore.
Regarding that: has anyone thought about replacing the extruders with some E3D's? http://e3d-online.com/E3D-v6/Full-Kit
Does anybody know which voltage is used on the current extruder heating elements? 24V I guess? Would also allow me to print at 0.25[mm], or even better: use 0.25[mm] for shells and 0.8[mm] for infill with dual extrusion.

Regarding the feeding gear: this one works well. it 'might' create some 'step-feeding' of filament due to limited amount of teeth. But I do not want clogging of the extruder either due to a bad feed-gear.

Lots of text I know, but these were just some ideas, not perfectly organized either. I hope that somebody has some thoughts regarding this! If there is interest I will keep you guys updated with pictures of the tests I'm conducting (and the wavy pattern I'm talking about.)


EDIT: there's also general settings that influence this behavior like amount of shells, infill, layer height, etc. but for maximum quality and some durability of the model I often find myself printing at 0.1[mm] layer height, 0.4[mm] layer width with 2 shells and 15% infill - if the height-width rate isn't good, then switching to E3D would allow me to use a 0.25[mm] nozzle. Infill has almost no effect on surface quality with 2 shells. 2 shells looks different then 1 shell.

EDIT2: here is a topic that has pinned down the most (most topic disregard it as z wobble, which is not the case here) http://forums.reprap.org/read.php?1,214990
this picture shown (exaggerated) what I'm talking about: http://forums.reprap.org/file.php?1,...e=ripples2.JPG
(NOT MY PICTURE - MY RESULTS ARE A LOT LESS VISIBLE, BUT SIMILAR TOO THIS)

My guess here would be that you are using micro-stepping for the extrusion stepper and the stepper motor is a cheap one.

Micro-stepping is fine in theory but in practise it is never accurate due to build and component quality inside the stepper.

The fix is to use a geared stepper and/or to use a top quality stepper motor though the problem is still there no matter how much you pay for a stepper motor, it is just not as bad.

Bit of arithmetic:

If you have a 13 mm toothed gear then one step is 0.2 mm of filament.
At 1.75 mm diameter that is 0.4912 mm^3 of filament.
With a 0.3 mm nozzle that equates to an extruded length of 1.74 mm per step.

If you are using half micro-stepping then each half step should be 0.869 mm of filament but due to inaccuracies in the half step one will be more than the other.

If your "oscillations" are 1.74 or so period then that is probably the problem.

Attached a picture of something on my printer that seems to show the same thing. The oscillations are just under 2 mm apart so that seems to fit.

I don't get those lines.

But I tend to print as fast as I can. Doesn't seem to effect quality.

That said - I couldn't care less about that sort of thing anyway :-)

I think that faster printing will lower the effect due to elasticity in the molten filament within the melt chamber. Greater layer height should also make it less visible I think.

Someone should check my arithmetic. :)

I've added a file to show you exactly what I get on my prints (this is 0.15[mm] layer height) though, much worse on 0.1[mm]!)
http://3dprintboard.com/attachment.p...2&d=1413906927

Quote:

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Originally Posted by Mjolinor

My guess here would be that you are using micro-stepping for the extrusion stepper and the stepper motor is a cheap one.

Micro-stepping is fine in theory but in practise it is never accurate due to build and component quality inside the stepper.

The fix is to use a geared stepper and/or to use a top quality stepper motor though the problem is still there no matter how much you pay for a stepper motor, it is just not as bad.

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Ok! that sounds like a very plausible cause too!
But.. I don't know if I'm using micro-stepping, and I do not know whether my stepper is cheap or not (willing to buy new ones though!)

Do you perhaps know what I need to look for in a stepper motor (for Flashforge Creator)?
And do you think this is for feeding or for X & Y too?

Quote:

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Originally Posted by Mjolinor

Bit of arithmetic:

If you have a 13 mm toothed gear then one step is 0.2 mm of filament.
At 1.75 mm diameter that is 0.4912 mm^3 of filament.
With a 0.3 mm nozzle that equates to an extruded length of 1.74 mm per step.

If you are using half micro-stepping then each half step should be 0.869 mm of filament but due to inaccuracies in the half step one will be more than the other.

If your "oscillations" are 1.74 or so period then that is probably the problem.

Attached a picture of something on my printer that seems to show the same thing. The oscillations are just under 2 mm apart so that seems to fit.

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I got lost in your math... completely. :confused:

But I will measure my oscillations (which look quite similar to yours!) as soon as I get home. The only difference being that I use a 0.4[mm] nozzle.

But in conclusion: I need to scratch all my thoughts and focus on the stepper motors that feed the material? Better motors = more consistent feeding, or can I change the firmware somehow regarding this?


Thanks for the help btw, really appreciate it!

And yes, larger layer height means more extrusion so the variations between steps are much less noticeable. (at least, that is my observation from all this)

Of the two possibilities the geared stepper will provide better results though I do not know if you can change the extrusion parameters on the Mightyboard or not. A more expensive stepper will only reduce it, you cannot cure it that way and you will be gobsmacked at how much a UK or German made stepper costs. You also run the risk of fraud however you buy it. English stickers on Chinese goods are too damn common of late.

http://www.aliexpress.com/item/EU-Fr...054390403.html

These are what you want and it is a good price but you are going to have to do some engineering to fit them because they are longer. It may not even be possible to fit them on the head and you will increase the weight and therefore the ability of the head to respond to requests for speed change (more inertia). Another potential problem with a geared extruder is the possibility of backlash in the gears. A planetary set minimises this but you may have to recalculate your extrusion retraction.

I think they have to be using micro-stepping because a minimum extrusion length of 1.74 mm is way too much. They are probably using 1/16 microsteps, you could find that in the specs somewhere I think if you need to know.

Gearing down your stepper means that speeds will be reduced so if you applied the same logic to your X Y steppers it would certainly improve things but I think the maximum speed the stepper drivers can pulse at may mean that you wait for ever to make things. I don't think the improvement in quality would be worth the expense and hastle. You would be better to put your money into getting rid of all the plastic bits inside the printer and using chains instead of elastic bands to drive the axes. It's all down to cost in the end. If you want to spend as much as a Stratasys cost then you would be better buying a Stratasys. :)

Quote:

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Originally Posted by Mjolinor

Of the two possibilities the geared stepper will provide better results though I do not know if you can change the extrusion parameters on the Mightyboard or not. A more expensive stepper will only reduce it, you cannot cure it that way and you will be gobsmacked at how much a UK or German made stepper costs. You also run the risk of fraud however you buy it. English stickers on Chinese goods are too damn common of late.

http://www.aliexpress.com/item/EU-Fr...054390403.html

These are what you want and it is a good price but you are going to have to do some engineering to fit them because they are longer. It may not even be possible to fit them on the head and you will increase the weight and therefore the ability of the head to respond to requests for speed change (more inertia). Another potential problem with a geared extruder is the possibility of backlash in the gears. A planetary set minimises this but you may have to recalculate your extrusion retraction.

I think they have to be using micro-stepping because a minimum extrusion length of 1.74 mm is way too much. They are probably using 1/16 microsteps, you could find that in the specs somewhere I think if you need to know.

Gearing down your stepper means that speeds will be reduced so if you applied the same logic to your X Y steppers it would certainly improve things but I think the maximum speed the stepper drivers can pulse at may mean that you wait for ever to make things. I don't think the improvement in quality would be worth the expense and hastle. You would be better to put your money into getting rid of all the plastic bits inside the printer and using chains instead of elastic bands to drive the axes. It's all down to cost in the end. If you want to spend as much as a Stratasys cost then you would be better buying a Stratasys. :)

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Thanks for the help!
I think that geared stepper would allow for more fluid feedrate. I will take pictures of what I mean with the current feedrate. It's possible to increase the feed in software, so that shouldn't be an issue.
Will get back to this with pictures tonight! (and hopefully an idea on how to apply these motors in the current build.)

I don't think mass is a problem, because I already print really slow; and if it becomes a problem I'll just lower the max. acceleration settings.
Also, I don't think I need to change everything to Stratasys quality. It's just that this is currently my largest bottleneck quality wise. (printing at 0.05 looks perfect in X & Y direction, but creates these ugly vertical osculation.)

If you go to a 10:1 planetary geared stepper then the feed rate steps will need to be 10 times as much and the oscillations will be 1/10 of the size, probably not visible at all I would think.

If you wanted to get inventive then you could probably try to even out the steps on your existing steppers by adding small resistors in the wires to finely adjust the current during the microsteps but that would be a lot of trial and error and take lots of time I think.

I have been thinking about this and if the cause is as I suggest then printing a flat panel will show the same pattern on the horizontal surface.

I suspect however that you do not have this pattern on a horizontal surface.

Just more thought to complicate things. :)

Ok, I promised images so here they are!

I printed a cube at 0.05 layer height (0.4 layer width) in PLA at 200 degrees (usually print at 185, but this was a test - test failed; print quality is exactly the same.)
To give you an idea of how it printed:
http://i.imgur.com/MWzDpSf.png
It started right-back-side, and went clockwise doing 2 shells (first inner shell, then outer shell at half speed)

Left side:
http://i.imgur.com/JlrQbgB.jpg

Front side:
http://i.imgur.com/fBhU7Fn.jpg

Right side:
http://i.imgur.com/s9rp9JC.jpg

Back side:
http://i.imgur.com/BWuVldB.jpg


This left side was is very unusual (perhaps it had to do with the temp? or the layer height??) but normally my problem is (as visible in the above images too) this:
http://i.imgur.com/Ko1MivH.jpg

Ugly vertical waves....
BUT, they are very consistent!

Now I am aware that these are partly generated by mass suddenly stopping (inertia?) - but I've tweaked this a lot already in the onboard preferences (regarding acceleration)
THESE particular waves that you see remain even on flat lines that go on for 100+[mm]!
So be it waves / oscillations / loose belts / whatever; I want to get rid of these. I know that they 'dissapear' when I print at layer heights above 0.18[mm], but I'm looking for suitable solutions for these layer heights too.

Mjolinor, thanks for the ideas so far! I am now printing a large flat surface (at 0.25 layer height) to show you the top surface and to prove that the printer doesn't show these waves at larger layer heights.

Ok, here's the top surface: (0.25 layer height, 0.4 layer width)
I'm seeing sort of a wave in there?? But that could all be because of the underlaying layers?
http://i.imgur.com/X7IJlM6.jpg

Here's the entire album so you can judge for yourself:
http://imgur.com/a/wF4a0

Any advice would be appreciated, willing to try anything! :p

Also this guy: http://www.tridimake.com/2013/01/how...ker-print.html
Is getting vertical waves too (when printing at 75 micron with an ultimaker) but its much less visible.

All I see is the typical surface finish you expect when the surface is made of layers of thin lines of plastic.

I think perhaps you are expecting more than this type of printing/manufactuing can acheive.

Quote:

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Originally Posted by curious aardvark

All I see is the typical surface finish you expect when the surface is made of layers of thin lines of plastic.

I think perhaps you are expecting more than this type of printing/manufactuing can acheive.

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I know I know! I am what we Dutch people would call: an antfucker. :D

Just another question that came to mind:

If you take hold of the extruders and move them around (like when leveling the bed or something) do you notice a difference in how 'easy' it moves in both directions?
For me it moves left<->right no very smooth. But front<->back is less smooth (more bumpy?). Assumed it was normal due to added weight, but just wanted to check.

mine seems to move equally well in all directions.
But I don't move it by hand when it's using the motors itself - like when bed levelling.

So that could probably account for the resistance.

I can only assume you have larger ants in the netherlands than we do in england :-)
Or smaller.......
lmao

(that's two rude comments I've made on this forum in five minutes - I think I'll go do some work lol)

How smooth it is when moving it manually depends on how fast you move it. Steppers generate when moved, you can test steppers very easily by connecting them together electrically in pairs, turn one and the other will turn because it is fed signals from the one you are turning. When you force them to turn while installed on the printer they electronics can do weird things like turn on the transistors or turn them off so at seom speeds it moves really easily and at some speeds it is quite hard.

I have just been making a Gcode file to print single lines on the bed. Mine doesn't yet show anything useful but I will keep at it and once I get it smooth I will then look at the lines it makes under a microscope.

This image is of a single line 50mm long and during that 50mm 1mm of filament is extruded.
1 mm extrusion is 5 full steps so if there is a problem with the micro-stepping I should see 5 oscillations in the 50mm so 10mm apart.

I am not sure it si enough to call it but the oscillation is certainly there. It is the same for a Y print as an X print.

Attachment 3216

Ok, apparently I could lower the acceleration even more! (something about different usage of comma and dots for decimals in Dutch and English...)

Previous prints (50 micron and 250 micron stacked on each other) :
http://i.imgur.com/wEKIhkq.jpg
(don't worry about the top, I stopped the print halfway through and had some funky temp. settings)

Same prints, but acceleration lowered by factor 10:
http://i.imgur.com/7J3eZWb.jpg
(took too long to print them so I cut them both of before the end.)

That looks already a lot better and I don't feel the vertical waves anymore with my nails! (though they are still a bit visible under decent lighting)
Will spend rest of week (or two weeks depending on how much free time I have) to figure out an optimal acceleration setting and then recalibrate all the other settings!

So, most of the problems I had were user-failure, but there is still some oscillation present, so any super-solutions are still welcome (and of course very interesting!)

Wow, that is one hell of a difference.

Are you changing the acceleration in replicatorG > machine > onboard preferences?

Care to post your numbers please.

Is this the same problem?
http://3dprintboard.com/showthread.p...rring-features

Awesome stuff!! Glad someone is working on it, that damn shadowing has always been an issue for me too - pretty much on any sort of hole that's printed or detail on the vertical. I would love to know what you did to get that final print, my FF is to the point now where it's done over 2000 hours, and although it's printed some awesome stuff I have never really gotten down to the nitty gritty.

I thought originally like Curious, that you were probably thinking these machines were capable of alot more than they really were, but as you have proven that's not the case and if you spend the time and effort you can get them printing just as good as a 3k ultimaker.

you guys have already mentioned it and are all over the cause of it. its not your steppers. it all this boils down to resonance from sudden direction changes. almost every machine does it to some degree. some are better than other but this is what core xy movement gets rid of or atleast limits. unfortunately printers with core xy are extremely limited but you will be seeing it more and more on newer printers being released. this can also come right down to the material your printer is made of, how rigid the construction of the frame is and if the bed is cantilevered like on a mb/ff and tons of others and also the weight of the moving print head. you can lower the acceleration which can help a ton but this can also just be inherent in your printer's design and you will never get rid of it 100%.

Quote:

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Originally Posted by Mjolinor

Wow, that is one hell of a difference.

Are you changing the acceleration in replicatorG > machine > onboard preferences?

Care to post your numbers please.

Is this the same problem?
http://3dprintboard.com/showthread.p...rring-features

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Yep, same problem!
I'll post some numbers that I've used below;

Quote:

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Originally Posted by Geoff

Awesome stuff!! Glad someone is working on it, that damn shadowing has always been an issue for me too - pretty much on any sort of hole that's printed or detail on the vertical. I would love to know what you did to get that final print, my FF is to the point now where it's done over 2000 hours, and although it's printed some awesome stuff I have never really gotten down to the nitty gritty.

I thought originally like Curious, that you were probably thinking these machines were capable of alot more than they really were, but as you have proven that's not the case and if you spend the time and effort you can get them printing just as good as a 3k ultimaker.

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Just a 3k Ultimaker? We'll get it to print much better than that! :rolleyes:

Quote:

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Originally Posted by jimc

you guys have already mentioned it and are all over the cause of it. its not your steppers. it all this boils down to resonance from sudden direction changes. almost every machine does it to some degree. some are better than other but this is what core xy movement gets rid of or atleast limits. unfortunately printers with core xy are extremely limited but you will be seeing it more and more on newer printers being released. this can also come right down to the material your printer is made of, how rigid the construction of the frame is and if the bed is cantilevered like on a mb/ff and tons of others and also the weight of the moving print head. you can lower the acceleration which can help a ton but this can also just be inherent in your printer's design and you will never get rid of it 100%.

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Yes, I understand. Perhaps I'll make some parts out of aluminum as soon as I've got a CNC router to improve it a tiny bit more.
And even though my photo doesn't show it, in the last picture there is also some of this shadowing going on, but it's almost not visible (and you can't feel it with your nail) - so with some finish (paint) it'll look very clean.

Ok. Some numbers I tested yesterday - as a disclaimer; I just lowered it by a large amount and didn't test anything time-effeciency-wise yet. NOR have I tested any preferred settings. This will all be done over the following weeks.

Not at home, so have not got exact screenshot, but the acceleration settings can be changed by going to: RepG->Machine->Onboard Preferences->Acceleration

There you will see:
http://4.bp.blogspot.com/-ykyqGwIUxi...references.png
I am using Sailfish 7.7 and I pressed 'Reset motherboard to factory settings' to get standard values.
Then I took the 'X acceleration rate (mm/s²)' and 'Y acceleration rate (mm/s²)' and set them to 100 (because standard is "1000" and not "1" ... man I would've figured this out sooner if us Dutch people would use international standard regarding commas and dots...)
Also changed the 'X/Y max junction jerk (mm/s)' to 8
Press 'Commit Changes'.
..
and that's it :) that's were the fine-tuning will start. (because this specific setting made it so that prints take about twice as long! - but you'll really see and feel what the machine is doing, which is very interesting and useful! I think that with a lowered acceleration setting you can easily up the maximum speed.)
If you want to test stuff, good luck and please post pictures and/or settings!

I don't think you can increase the max speed, the acceleration is there in order to allow faster overall movements.

If you turn acceleration off completely your machine will start jumping at every change of direction.

By reducing the acceleration you are not changing the behaviour at the corner but are just slowing the head between corners. If you increase speed you will start getting an overshoot at the corner.

Maybe I didn't explain it right:
With the test print (20x20x20mm cube) and the slow acceleration settings it was very clear what the machine did:
It came to a stop at every corner and started accelerating to max speed (took about 5mm (0-30mm/s)) and then it started deaccelerating about 5mm before the next corner.
That means that for 10mm in the 'middle' it was running at a max speed of 30mm/s. I think it can easily aim for a max speed (software-wise) of 60mm/s. This would probably mean that is would accelerate for the first 10mm, and then deaccelerate the last 10mm. (in this particular example.)

Because I feel now that the max. speed isn't hurting the machine, but the large acceleration is. But to get my prints to finish before 2017, I'd like it to print as fast as possible while remaining a good quality. I believe the formula for this is low acceleration and 'decent' max speed. Like a truck! Because currently I was running it like a scooter (high acceleration, low max speed) - but that doesn't work out because the mass of the extruderassembly is much fatter.. (like a truck.)

Also, stuff like overshoot can be adjusted with the JFK? JAK? JAJK? values on the onboard preferences. I adjusted these perfectly at my previous settings, but I'll need to set them again as soon as I have my speed-quality set up perfectly. Stay tuned!
(link: http://www.makerbot.com/sailfish/tuning/ with some explanations of above mentioned values and calibration methods)

I honestly can't see any difference.

But when you've got things sorted out - I'll probably copy your settings :-)

Quote:

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Originally Posted by curious aardvark

But when you've got things sorted out - I'll probably copy your settings :-)

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Chinese ancestors?

Quote:

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Originally Posted by Mjolinor

Chinese ancestors?

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Just intelligent ones :-)
Using what works is just common sense and if someone has more time to work that out than I do - only an idiot wouldn't use that knowlege.

And now I look, I can see the waves, and they are only at one end of the print. So the acceleration thing makes a lot of sense. Once the head gets up to speed the waves stop.

I don't envisage it ever being an issue visual wise, with what i'm liable to make - but anything that increases precision of prints without massive effort on my part, has to be a good thing :-)

I don't think it is related to the head coming up to speed at all. The waves will still be there but reduced as the overshoot is reduced because it reaches the corner more slowly. If it is doing an X move then the wave is created by the previous Y move. It is a property of everything in the universe be it central heating controllers or speedometer needles on cars, they all suffer from it and it cannot be cured, only minimised.

The proper way to minimise it would be with PID controllers on servo drives that have feedback. That would be one expensive printer. :)

I'm trying to find some good settings (will update later this weekend) but I was wondering if I could calculate 'perfect' settings based on the hardware.
So perhaps Mjolinor knows this one ('cause you seem to know a lot of this technical mumbo-jumbo)
How often per second does the motherboard / controller talk to the stepper motors?
What's the smallest step the steppers can make the extruder move in X Y directions?
What's the smallest length of material that can be extruded in one step?

I'm thinking I could use that to calculate which values allow for no floating point values going to the stepper which perhaps allows some small improvements?

What it is possible to calculate has already been calculated.

The oscillation is partly mechanical, it is stretch in the belts and movement in the end pieces caused by the impossibility of going from moving to stopped in zero time. Some of it is electrical but for exactly the same reasons, it is not possible to go from current flowing to no current flowing in zero time.

If you google "Ringing" there are lots of explanations of what it is and what causes it electrically but you will also see that it is applicable to everything including any mechanical, hydraulic or pneumatic system.

Try turning on the dynamic speed settings using Profitweak.

wouldn't that entail using makerware ?
Problem with that is that simplify3d produces much much nicer prints than makerware - without firmware adjustments. So going back to makerware would actually reduce print quality, regardless of the firmware tweaks.

I'm glad i found this thread. I'm fairly new to 3D printing and have a lot to learn. That's why I'm here. My story... I bought a Printrbot Metal Simple about 2 months ago. I have printed about 300 hours so far. I love this little printer. I noticed the "ringing" or "echoing" in my parts somewhere after about 125-150 hours were on the machine. I also noticed it's sound changed a bit. It picked up a slight vibration noise that i can not pinpoint. and it seems to be getting worse. I think its in the y axis stepper motor. Most of my "echoing waves" appear on the x axis face durring printing so that might make sense if the y-axis motor is having an issue (i.e. the y-axis is ping-ponging back and fourth following a y axis move while the x is traversing in a strait line) this printing a wave effect on the X axis face of the part. I'm guessing the motor is going bad. How many hours are stepper motors typically good for before the tend to wear out or "go bad in some way" Printrbot used some pretty chunky NEMA 17 steppers that physically appear to be very well built. I can't imagine it would wear out that fast. I'll try to post some pics tonight of the parts with the echoing before 100 hours and after 150 hours to show the difference. This is why I'm not to sure this issue is software / acceleration related. I think i might order a fresh set of GT2 belts and do a little maintenance and tighten some screws next week to see if it clears up the issue.

Stepper motors generally are really robust, they run for years at high temperatures with little change in their characteristics. I have a dozen or so Nema 23 and Nema 34 steppers here that are getting on for 30 or more years old and they work just the same as they did on day one. The biggest killer is people trying to mend them, once dismantled they wll never work again as they are magnetised in their assembled state and once the two halves are separated the magnetism goes out of the window.

The trouble is that the recent increase in all things computer has led to massive sales of low end, home user CNC type things and prices falling so I reckon something has to suffer and generally it is quality. I would not immediately think a stepper was failing, it would generally be at the bottom of the list after all else has been proven to be OK.

Quote:

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Originally Posted by Mjolinor

Stepper motors generally are really robust, they run for years at high temperatures with little change in their characteristics. I have a dozen or so Nema 23 and Nema 34 steppers here that are getting on for 30 or more years old and they work just the same as they did on day one. The biggest killer is people trying to mend them, once dismantled they wll never work again as they are magnetised in their assembled state and once the two halves are separated the magnetism goes out of the window.

The trouble is that the recent increase in all things computer has led to massive sales of low end, home user CNC type things and prices falling so I reckon something has to suffer and generally it is quality. I would not immediately think a stepper was failing, it would generally be at the bottom of the list after all else has been proven to be OK.

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Yeah, they are pretty hardy little devices.. I thought I had killed steppers in my machine but nearly everytime turns out to be an issue with a board or driver, it only once has ever been a stepper motor and that was a really cheap nasty clone of a Nema17 (those black 45mm ones, bit longer than the stock 40mm, hard wired and no label or serial#)

One one my machines runs the steppers really hot because I have the juice cranked up on the driver and they print at super speed, I expect them to die one day, I'm sort of trying to kill them :) but I don't think I will...