cant get extruder to feed filament

[rs50pilot]

Im using seeme 1.75 white abs. Measures about 1.88. I cant seem to the bolts just right so the filament will feed all of the time. It either has a lot of dust on the hobbed roller or it pushes te filament out of the rollers and under the being of the bowden tube. It will bunch up there and make a mess.
I tried 230 to 265 c. Anyone have a pic of how much there orings are compressed? I can feed the filament through the extruder by hand. It takes a little effort but doesn't seem that hard.

Between that and getting what does extrude to stick I'm batting 0. Tried hairspray and blue tape. I calibrated the extruder best I could and printed a ok hollow cube yesterday but today I had the problems above.
The first layer of the cube didn't stick that good and the skirt didnt stick at all. But the walls of the cube looked pretty good.

Any pointers?

[theverant]

My extruder is tight enough that I can't move the filament by hand through it. I can take some pictures later if you like. But that might be a place to start. The bunching sounds like another problem, like something is misaligned or there is a blockage.

[rs50pilot]

Well took everything apart. Found a tiny resistance in the Bowden Tube. Don't cut filament with dikes, use a razor blade and make a clean cut.

Cranked the extruder ul to 265 in the software which measured 220 on my thermocouple. 100 on the bed with blue tape and hairspray. I used a brand called " GOT TO BE GLUED" in a yellow can.

Thin wall part printed good a little lifting on the base layer corners. But layers looked good. So I went for the tornado.
Half way through the process the hotend hit the model and started dragging it around.

0 retract 1mm lift. Stringing on the ooze part in the calibration collection part. Gonna try to lower the temp to see if strings go away.

Im happy so far.

[theverant]

Good to hear you sorted it out!

[mhackney]

Also try a little more Z lift. I've now "standardized" on 2mm.

For finding the temperature sweet spot - I like to print a single wall hollow cube (like the calibration cube). With a .5mm nozzle go with a .2mm layer height - that will allow you to more easily see the "smooth" and will give you enough layers to do the following test:

First, by extruding in air, find the lowest temperature that you can extrude reliably. You should be able to extrude 10mm of filament at say 60-100mm/s easily and the extrusion should be smooth and not kinked.

Now, go and print 2 layers with your temp at your normal printing temp - 265° in this case. You are just trying to get a good base laid down.

Once the 2nd layer is printed, set the hotend temperature to the low value you determined above. Wait enough time for the temperature to go down and stabilize. Then print 2 layers. I put a little mark on that starting layer with a Sharpie.

At the completion of 2 layers, bump the temperature up 5 degrees. Let it continue to print while watching the temp. Once it gets to the new set point, let it print 2 layers and then bump up another 5° (with another tick mark). Repeat until you run out of layers to print OR reach your max temperature. You do not want to go over about 245°C actual temperature at the hot end or you risk damaging the PEEK and teflon tube. If you run out of layers to print, simply start another print but resume at the last temp you reached the first time around.

Watch carefully as you do the temp ramps. You are trying to find the lowest temp where the layer is spread down like butter, nice and consistent width and thickness. I do this for every new spool of filament, they are all different! Once I have the lowest temp, I add 5° to it for a little extra margin (sometimes I need to add 10, black filament in particular seems to require a bit higher temps) and use that for printing that filament.

Once you have the lowest temperature then you can start working on retract or wipe (in KISS) and other techniques to eliminate ooze/blobbing.

cheers,
Michael