Problem with print. Every x cm's of filament I getting too thin lines. What's wrong ?

PLA from Makerfarm, temp 185, nozzle 0.35, filament 0.3mm, print height 0.3mm... Speed 18mm/s, extruder filament ratio 1...

I just start getting those after 2 meteres of new PLA filament....

What should I do ? I can't print anything with that problem :/// (wholes on bottom/top)...

Did you measure the filament with a caliper at several points to confirm that the filament is causing the problem? It might be an issue with your extruder gears or extruder drive wheel/hobbed bolt that shows up every full revolution.

Ok I found that extruder just "jumping" and not passing filament to hot end...

No clear reason for that as everything looks ok. Whole printer making a lot of noise but I can't find a reason why extruder is jumping :///

Any idea or tips ???

looks like you've got some slippage and your temperature might be a tad too high, whats your retraction distance and travel speed?

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Travel speed- 130mm/s
Perimeteres: 20mm/s
Small per. 20mm/s
infill- 35mm/s
solid infill - 35mm/s
top solid infill: 25mm/s
gap fill 15mm/s

Retraction 1mm
Lift z - 0

speed 30mm/s
extra length on start 0mm
minimum travel after rtetraction 2mm
retract on layer change - yes



Filament size from 2.9mm - 3.12mm...

Edited 1 time(s). Last edit at 07/14/2013 05:31AM by mike1986.

if the filament is getting that large that would most likely be why it's having trouble going through the hotend,

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BTW, is it normal that I'm loosing all nuts ?? Every 1-2 prints most of nuts going off, even if they are tighten... For example I tightened nut on extruder bolt and again it went off (I can't use more force as it will stop rotating)... How do you deal with that ?

Is it just something with my model or all 3D printers has that problem ? I have thread lock so I can add it, but I just think if this is normal...

I checked it again. Now I have 3.02 - 2.92...

Same problem :///, I tried different current on extruder (higher), I tried to make it sure that filament is free to go (I'm just trying to print holder), but looks that this printer can't print anything bigger, it will move X (20-30 pixels so whole print is useless) or will start loosing filament by jumping extruder :///

uneven feedstock is a fact of life for reprap printers. tolerance is usually +/- 0.10mm, and consistent thru the roll. if you have less than this i would suggest contacting the vendor and asking what the tolerance is. possibly get a refund,



lay down enough feedstock to compensate to ensure that there is at least part coverage. turn down motor current to cause the feedstock to stall when pressure builds up. also perhaps lay down filament in thinner layer heights.

these tricks cause a sort of regulation by pressure rather than flow rate to some extent, minimizing effects of uneven feedstock flow.

What do you mean by "jumping"? Is it the stepper motor jumping around?

If not maybe try tighting the idler. I had this problem as well. When I'd turn the big gear at first it required more force to turn and plastic would flow. Then it would let up of prussure needed and very little plastic would extrude. This was for ABS but that shouldn't matter. I did end up turning my tempature up but I dont know if that had an affect on fixing it.


Yes I do believe it is normal for the nuts to become loose due to the vibrations of the printer. The Nylock nuts are good, but you could maybe try double nutting.

Ok.

Gear is working fine, bearings as well.


I found out that everything is moving but no filament is extruding and stays in same spot for x seconds (sometimes it will jump on bolt, I can't also move it by hand..)

For first few hours after assemble I had no issue with that...

What should I check now ?

Edited 1 time(s). Last edit at 07/16/2013 05:36AM by mike1986.

mike1986 Wrote:
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> I found out that everything is moving but no
> filament is extruding and stays in same spot for x
> seconds (sometimes it will jump on bolt, I can't
> also move it by hand..)

Sounds like the hot end isn't hot enough to me. If your extruder idler tension is high and the hobbed bolt is doing its part to feed the filament but it's not moving, then there's a jam in the hot end. Increasing the temperature should help.

But since this is PLA, your hot end tube is also going to appreciate a fan blowing on it to prevent a warm-but-not-hot-enough zone building up in the tube where the PLA has expanded a bit but isn't viscous yet.

Finally, once the hobbed bolt starts skipping, it will begin to shave filament off the stock and deposit it in the bolt's teeth, making subsequent feeding less reliable. If you're seeing this slippage with a regular period, there may be filament stuck in just one or two teeth and causing it to skip when it reaches those less-grippy teeth. Try cleaning out your hobbed bolt's teeth as well.

mike1986,

Did you ever resolve this issue? I think I am having the same issue, so would like to know how you have resolved yours, if you did.

Thanks!