Infill Issue

Hey,

I am having some issues with the infill on my RepRap Prusa i2.

I tried slowing the speed of the infill layers down, but that didn't help much.

The layer height is 0.1mm and i am not using a cooling fan.

Could this be the reason?

Attached is a photo of what the print looks like

Thanks, Alex

Edited 1 time(s). Last edit at 12/15/2013 09:37AM by ayouden.

looks a little too hot on your hot-end and maybe a little low on extrusion. This can happen also if the flat on the tip of your nozzle is too wide causing 'tear up' of previous passes.

Nozzle size and infill %? you might have better luck at 0.2mm layers, bridging is very tricky at 0.1mm

its not just your infill, its your perimeters as well, nothing looks clean..

try a fan, see if that helps, if not,....

Try to extrude 100mm of filament, feel your extruder to see if its consistently extruding the plastic, I use to get these type of prints when I first got my printer, it was fixed by tightening the extruder pressure, also my hotend was a bit crap, basically it was not extruding.. the filament was slipping...

you gotta keep in mind this process

Probe for whats going wrong,
Analyse the issue
isolate the problem, either hotend, extruder, or settings... like temp..
resolve it ..

Your layer height should correlate (be proportionate to) the size of your nozzle orifice. .1mm is probably too small. What size nozzle do you have?

I would think that your extrusion is an issue. what nozzle size, hot end type, and software are you using to calibrate your machine? also the pinch grip on most extruders needs to be very tight. also temp should be 170-210 for pla, and around 220-240 for abs. do you have any way to verify the temp is accurate?


try your z height at 100mm, and then run your extruder for a bit. does the speed it is running match the extruded amount? you really need it to go thru at least 50-100mm of feedstock to see how it behaves with back pressure. adjust your tension adjust your speed on e axis until it is faster, or until you get it working reliably at a slower rate.

also have you calibrated your machine correctly so that in z axis it moves 10mm, when you send the command to move it 10mm, does your x and y axis do the same?

verify with calipers, or a cm ruler.

also i would try repetier host as it has an excellent gui for doing all the above. it can be found here: [www.repetier.com]

instructions on machine calibration can be found here thanks to triffid Hunter: [reprap.org]

I've got something similar when I turned off the cooling fan completely to prevent warping, because the fan was indirectly cooling the heat bed quite significantly. It caused the heat to creep up and result in inconsistent extrusion.

I managed to work around the problem by using kapton tape to tape a temporary fan shroud to direct the air purely to the hot end and not to the heat bed. Let me know if it works.

Hey,

Thank you for all your suggestions about this topic.

I found a solution which works for me at least, what I have done is set the infill speed to 20 rather than the default 60 in Repetier. I very rarely get any faults on the infill now and my prints are becoming much stronger because of it.

Thanks

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but 20mm's a second is so slow, id be getting frustrated at that speed...
most printers should be able to do atleast 40mm's on the infill , something is going on if you cant extrude faster and it looks like that
Its early warning for me, if I cant extrude at 40mm's+ something is going on,,


First things I check
-Extruder, make sure its not slipping, I can hold the filament very tightly and my extruder is strong enough to pull it from my fingers and it wont slip
-Manually hand extrude it, load the filament into the hotend, have it all hot and ready, hand feed it, it should not be to hard, if it is, something wrong with the hotend... I remember when I had crappy j-head clones, it took so much pressure the steel rods would bend and only a little bit of plastic would come out...

its worth while getting a few good hotends to play around with