constant extrusion issues

Hey everyone, I have a small issue with my Prusa i3. After finally getting it to work for 2 days (not perfectly mind you), it now seems that something is prohibiting the filament from reach the aluminium block and nozzle. its definitely not a clog because I checked every single part twice for any clogs and I ran the filament threw the nozzle itself (while hot), its definitely working.

it feels as if the filament is getting caught on some little ridge, but I cant seem to figure out where it is or how to fix it, can anyone help?

and on a side note, when it was working, I couldn't seem to get the ABS to stick properly, I added very strong hairspray to the hotbed, but the parts still warped and came loose. I printed at 225 degrees C on hot end and 110 degrees C for the hot bed

if anyone could help with the first problem that would be amazing! thanks a lot peeps!

Your printing ABS too cold. I print mine at 235-240 normally.

1) extruder temperatures seem to generally be pretty accurate. You're printing too cold for ABS. Turn the temperature up to 235-240C.

2) pull the filament out of the extruder. Is there a small, rounded divot where the filament was pressed against the drive gear? If so, increase the pressure from the pinch roller to push the filament harder against the drive gear. You may have to adjust the extruder motor current.

3) printing ABS is not for beginners, and especially not on open frame machines. Bed temperatures are often reported incorrectly by printer electronics. You must check with a thermocouple (not an IR thermometer) to read actual surface temperature. Actual surface temperature should be about 105C. You must print the first layer slowly, maybe 20-30 mm/sec. Your bed must be flat, level and evenly heated. To print anything but very small ABS parts you must enclose the printer and get the enclosure temperature up to 45-50C or the prints will warp and delaminate.

Most of the i3 kits do not have adequately and evenly heated, flat print beds, so most people clip a piece of glass on them. The glass is a thermal insulator that creates a temperature drop from the bed heater to the glass surface. In order to get the surface up to 105C you may have to set the bed temperature to 115 or 120C, and then wait for a long time.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Try a piece of cardboard or better still foil bubble wrap type stuff over the bed whilst heating it. It will heat 3 times faster and ensure the top surface is hotter when you print your first layer. Insulation under the bed like fibreglass matt helps too. Temperatures need to be higher. What hotend are you using? If its an all metal clone just give the inside of the throat a good polish with wire wool/some multistrand copper cable etc... in an electric drill, to ensure there are no little burs in there. Make sure the throat and nozzle but against each other squarely when assembled and neither has a slightly angled end, if so file/sand then re-polish. Make sure the nozzle is a fraction out of the heater block then screw the throat in, then tighten the nozzle tight, then do it again with it all heated up.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

hey guys! thanks alot for all the help, I am definitely gonna try all of this tomorrow, hahaha its late here in SA right now...Its good that I now know to heat up to 240, and Im gonna try all the stuff with the bed, it already has glass layd over, and as for that fillament block, Ill definitely try your advise DjDemonD, I think thats the problem...