EZStruder is always jamming with PLA

[deadnoob]

I've had my Rostock Max V2 for about 2 weeks. ABS prints ok, but any time I try to do PLA, my EZStruder jams with PLA. II've tried to play with the settings by using temperature 175/180/190/200/210°C, with and without retraction, and I've increased/decreased printing speed. Every single time I end up with a messed up extruder that I need to take apart to get the filament out. Anyone have any tips? I thought it might be caused by the PLA overheating in the hotend causing a backup, but like I said, even at the lowest temperature this is happening. Also, I have the PEEK fan installed. I only want to print PLA so at this point the printer is useless to me. Thanks for the help.

Images:
[img]http://i.imgur.com/kvOn8AI.jpg?1[/img]
[img]http://i.imgur.com/iVLPgtI.jpg?1[/img]

[jeffhuber]

Where is your PLA from? Have you tried drying it out? What is the diameter of the PLA? (do you have a micrometer to check? should be less than 1.8mm or it probably won't work)

[deadnoob]

One roll is from Sainsmart and the other is from FilamentDirect.com. Both have printed OK on other printers. I checked both diameters and they are good, both around 1.73-1.75mm. I haven't tried drying it out. How would I do this?

I should also mention that they print fine for about an hour or so, then this randomly happens. It isn't something that is immediate.

[jmpreuss]

That picture is really interesting. My PLA doesn't smush up like that, it looks like how ninja flex would smash up. My guess is that the extruder motor is getting really hot and is softening the PLA meaning it can't push itself anymore.

[jeffhuber]

Can you diagnose by starting the filament just past the motor and seeing how far it gets before failure? I'm wondering if back force from the hot-end or a push fit connector, or your bowden tube is causing the error further upstream.

Sorry about the problems! Kits are definitely hard to get right. I'm still getting all the bugs out of mine too.

[DavidF]

That picture is really interesting. My PLA doesn't smush up like that, it looks like how ninja flex would smash up. My guess is that the extruder motor is getting really hot and is softening the PLA meaning it can't push itself anymore.

Very interesting!!! Maybe its not pla?? Try burning a small piece of filament to be sure, if its pla it burns with a nice clean blue flame. If its abs it burns with a black smoke and stinks big time. I have to agree that does look like what happens when printing the ninja flex, I had to run at 25% speed to get the ninja flex to print without jamming up in the extruder like that....

[deadnoob]

That picture is really interesting. My PLA doesn't smush up like that, it looks like how ninja flex would smash up. My guess is that the extruder motor is getting really hot and is softening the PLA meaning it can't push itself anymore.

Yes, the stepper does get very hot. This was something I suspected as well, but I saw some other posts saying that the motor is fine if it gets hot. Do you know what could cause it to get so hot? I would think the only thing would be if it had resistance when extruding, but like I said, I've tried a ton of different setting all with the same result.

Can you diagnose by starting the filament just past the motor and seeing how far it gets before failure?

The filament can go from all the way at the extruder to out of the hot end with no problems.

[Polygonhell]

How hot? 50C is fine on a stepper, 80C isn't.
Stepper get hot because they are being supplied too much current, and generally hottest when they are not moving.
The filament is being ground by the hobbed roller, that means it't encountering too much resistance further down the chain.
I'd try printing it hotter than 210, try 230, if it works drop the temperature down, unless you've actually used a thermocouple to measure the Hotend temperature, it can be miles off.
The other thing to ensure is that at the temperature you are printing you can feed filament by hand with reasonable resistance.

[guanu]

does the sticker on the motor say wantai or kysan?

Guanu

[deadnoob]

Guanu - it is a kysan motor.

Unfortunately I don't have a temp sensor so I don't know exactly how hot the motor is. It is definitely hotter than the steppers that drive the belts. I'm going to try printing at 220-230C tonight to see if that helps. Everything I've read online said that was too hot for PLA, but we'll see.

[DavidF]

Guanu - it is a kysan motor.

Unfortunately I don't have a temp sensor so I don't know exactly how hot the motor is. It is definitely hotter than the steppers that drive the belts. I'm going to try printing at 220-230C tonight to see if that helps. Everything I've read online said that was too hot for PLA, but we'll see.

Try this as an indicator. Cut a length of pla and abs about 2" then lay both of them on top of the stepper near the driver with a bit of length sticking out past the motor. Then print something. This should give an indication of how hot the extruder stepper is getting. If they droop over, something is wrong. I can't picture the stepper getting so hot that it softens the filament without something else dying first....
What print speeds are you running at??

[deadnoob]

Try this as an indicator. Cut a length of pla and abs about 2" then lay both of them on top of the stepper near the driver with a bit of length sticking out past the motor. Then print something. This should give an indication of how hot the extruder stepper is getting. If they droop over, something is wrong. I can't picture the stepper getting so hot that it softens the filament without something else dying first....
What print speeds are you running at??

Good idea! And that might have helped me a lot (at least find the problem.. still no solution). Check out the pictures taken 5-10 minutes apart. Grey is PLA, white is ABS. It definitely seems like this is the problem. Also adding to this, I printed a small object last night, maybe 30-45 minutes. When I went to look at the filament today, it was completely crushed bewteen the hobbed roller and spring loaded bearing. That leads me to believe the filament is getting warm enough to soften, and left for long enough, it is deforming. Although it gets hot enough to deform the plastic, it still seems like the filament would be moving past the extruder fast enough that it wouldn't have time to heat up that much. I'm printing at 30mm/s, but have done up to about 50mm/s. I also tried without retraction and the same result every time.

Before: [img]http://i.imgur.com/wokAypC.jpg?1[/img]
After: [img]http://i.imgur.com/PmiSvIy.jpg?1[/img]

[DavidF]

That's not too awfully bad, pla has a glass transition.temp of about 138'F, and abs has a glass transition temp of about 220'F.
By the look of it I think your stepper is running maybe 120'F. That's not overly hot. But if your extruder is plugging, the stepper could heat up more.
Is there any marks on the filament where the hobbed wheel gouged the filament where its all balked up at?? Have you ever had the stepper kick back?

[deadnoob]

That's not too awfully bad, pla has a glass transition.temp of about 138'F, and abs has a glass transition temp of about 220'F.
By the look of it I think your stepper is running maybe 120'F. That's not overly hot. But if your extruder is plugging, the stepper could heat up more.
Is there any marks on the filament where the hobbed wheel gouged the filament where its all balked up at?? Have you ever had the stepper kick back?

My print at 215-225 worked (my extruder didn't maintain the 225 temp very well though, dropped down to 208 at one point when it was set for 225). I guess the extruder was slowing the extruder down a bit causing the backup. At ~220 the PLA flows easier than at 190, but the extruder motor didn't seem any hotter or cooler either way.

I don't really like this solution of increasing extruder temp though - print quality is not as high as the lower temp. Maybe I'll just have to adjust print speed and retraction settings, but still doesn't seem great. Also, the PLA got all deformed at the hobbed wheel after the machine shut off. The PLA melted between the wheel and bearing :/ This means I'll have to remove the PLA after every print..

I haven't seen any kickback at all. No marks on the PLA, but it is hard to check that when it fails. When it fails, it chews up the PLA pretty good.

[DavidF]

Leave the "melt sticks" in place and keep printing trying different extrusion temps.
With all the knowledge on this form it is sure to be sorted out shortly.
Pictures of your prints would be a help also.

[DavidF]

Did you try burning the filament just to make sure it is pla?? Probably is, but just to be certain......

[deadnoob]

Yes, definitely PLA - blue flame (and smells good when it prints)!

Anyways - I think the solution might be to add a fan pointing to the stepper. I have a decent sized desk fan blowing on the extruder motor right now and it is staying very cool. I'm going to try to get a smaller fan that I can mount to the stepper/Rostock and wire it up. Would there be any power issues if I use the same electric slots on the Rambo as the PEEK fan? I think there are extra ports, but I want it on all the time anyways, so can I just plug it in the same slots?

[DavidF]

Yes, definitely PLA - blue flame (and smells good when it prints)!

Anyways - I think the solution might be to add a fan pointing to the stepper. I have a decent sized desk fan blowing on the extruder motor right now and it is staying very cool. I'm going to try to get a smaller fan that I can mount to the stepper/Rostock and wire it up. Would there be any power issues if I use the same electric slots on the Rambo as the PEEK fan? I think there are extra ports, but I want it on all the time anyways, so can I just plug it in the same slots?

It might fix the problem, but I think its more masking an underlying problem that I would like to try and figure out.

[deadnoob]

It might fix the problem, but I think its more masking an underlying problem that I would like to try and figure out.

Edit: The print that was going with the cooler fan just failed. The stepper was in fact kicking back.

It seems like the stepped is running hot, which normally is fine, but then it starts kicking back and not feeding any filament through. The filament gets warm and soft and the extruder then chews it up. That didn't happen this time because the fan kept it cool so the PLA didn't get chewed. I was able to see the kicback without having PLA all intertwined in there.

So.. why would the stepper skip? Is this a stepper driver overheating issue? It must be a hot end issue that is backing up the filament. I think I'm going to take it apart to make sure it isn't clogged. I doubt it is since it printed fine at 220C.. hmm...

Also, I think I have this problem with the tower steppers too - sometimes I'll get a layer misalignment, but all above layers are in that same misalignment. Could that be one of the tower steppers skipping a step? Maybe I'll wait until the first issue is resolved to solve this one.

I should also mention, I was getting power supply overheating so I am currently running the machine without any of the black acrylic in an air conditioned environment. It shouldn't be getting too hot on the board.

[guanu]

ok, kysan now that makes sense.... load up your firmware, go to line 701 of configuration.h

change:

#define MOTOR_CURRENT {175,175,175,200,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

to:

#define MOTOR_CURRENT {155,155,155,165,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A KYSAN MOTOR CURRENT SETTINGS )

and your problem should go away... you will have more torque and lower temps!

no need to change anything else, your eeprom will hold all your calibration


Guanu

[mechneering]

deadnoob, I am/was having the exact same problem you are describing. same jamming on the extruder and the power supply shutting down from overheating. I also removed the side covers from the base. follow the instructions by Guanu. I just updated my firmware and adjusted the current settings for my kysan motors. they are running much cooler now. and I also suspect I will be able to put my acrylic covers back on the base. It might be good to add this bit of info into the instruction manual. it might save some people a lot of time and failed prints. Good luck!

[deadnoob]

Adjusting the current seems to have done the trick! I haven't had time to run a long print since I want to be near the printer in case it jams, but from the 2-3 hour print I did, the motors were cooler than before. The test strip of PLA didn't melt like before (only got a tiny bit soft). Now I just need to figure out my retraction settings and it will be perfect

Thanks!

[Mrfrankl]

does the sticker on the motor say wantai or kysan?

Guanu

I've been having the same exact issues, but my motor is a wantai.

ok, kysan now that makes sense.... load up your firmware, go to line 701 of configuration.h

change:

#define MOTOR_CURRENT {175,175,175,200,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

to:

#define MOTOR_CURRENT {155,155,155,165,0} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A KYSAN MOTOR CURRENT SETTINGS )

and your problem should go away... you will have more torque and lower temps!

no need to change anything else, your eeprom will hold all your calibration


Guanu

Will this solution work for me as well?

[guanu]

your issue appears to be hotend jam, rather than extruder jam... the reason for the current change was putting over-current in the kysan motors causes them to get hot and can make pla soften by the extruder.. having the current closer to what the motor wants makes it run better... looking at the plug in the pic, your issue seems to be heat creep, make sure the peek fan is always on.. if its not on full all the time, heat can creep up the peek section and soften the plastic early, causing it to swell and plug before getting to the nozzle, thats really what your pics look like what is happening.

Guanu

[Mrfrankl]

I did a little digging through other threads on here and I found a conversation discussing the containment of excess heat (ie heat creep).

The peek fan MUST be on at 100% all the time.

You can wrap the heater block with silicone tape to insulate it, that helps a lot.

Your resistors could be burning out or connections to them poor, this is also a common cause of not being able to get hot end up to temperature.

UPDATE:

The kapton tape wrap around the heated barrel below the PEEK was the first thing I tried and it worked! I also have silicone tape which I'm sure would also work, but the Kapton happened to be closer on the bench...

Now I only have to recheck the PID calibration but the hot end hit set-point just fine.

Thanks for the ideas and I hope this helps others with the same problem.

Mark

Is this my solution or do I need to make adjustments in configuration.h???? (kinda lost here)

BTW, thanks for your help... trying to get a solution to my print issues has been both a head scratching frustration and an enlightening journey (not too often the two coincide).