Width of extruded filament reduced
Hi all,
I have recently received my fully assembled Mk3 and have been having a blast trying out the test prints.
Everyone I show the gear and bearing to wants one, and I have printed 5 so far.
Printing the 6th one however something has changed and the quality of the finished product is not good - I can see through the top and bottom surfaces into the hollow structure inside. The width of the filament track laid down appears smaller as I can now see gaps between two parallel neighbouring lines of filament. There is also *a lot* more slop in the gears compared to the first 5 prints.
Top:
Bottom:
I have tried using the acupuncture needle to clear the nozzle, and when I purge material using the load filament function it seems to be flowing consistently i.e. not thick then thin then thick etc. I've done this at both 215deg and 250deg nozzle temperature.
One observation is the filament continues to extrude for about a minute after the filament stops being fed into the extruder. Is this normal?
I've printed 3 gear and bearing prints so far (#6, #7 and #8), using the acupuncture needle to clear the nozzle between each print,but have gotten the same results each time.
Photos of the top and bottom of the gear and bearing attached.
Any ideas why the print quality has gotten worse and what can I do to fix it?
Re: Width of extruded filament reduced
Well, if you have eliminated all other possibilities. Such as temperature settings for you filament, and first layer height settings, I have found this usually means a partial clogging issue in the nozzle.
When this happens to me I usually try two "cold pulls." If the problem is not solved with a cold pull, I replace the nozzle. Every time I have replaced a nozzle when this issue happens, it always clears up.
I buy the cheap .4 nozzles on ebay that come from china. I recently bought 25 for under $20. They work just as well as the one that came with the printer. When they fail, I toss them. For the price, who cares?
Re: Width of extruded filament reduced
Your first layer is not good. Make a Z-level calibration again and adjust until you get a tight and fine first layer.
If you have changed any parameters in Prusa Slic3r, then change these values back to original settings and try again.
Bear MK3 with Bondtech extruder
Re: Width of extruded filament reduced
Thanks George, a cold pull helped (plus I learned how to disassemble the nozzle and extruder which is always good to know!)
Increasing the flow to 150 improved matters but still not quite back to where it was originally. I have gone back to 100 flow and am doing a z calibration of the z height now, results are looking promising so far.
will post thre results
Re: Width of extruded filament reduced
Tuning the Zheight made all of the difference!
My previous setting was far too low, so it was squashing the filament into the bed and would dislodge underlying layers when it was printing fills.
I wound the z offset right up until the calibration test was printing terrible lines, then wound it down in 50um increments until the lines looked even and the patch at the end of the calibration test printed without gaps between the neighbouring lines.
I ended up about 50um higher than what my previous settings were, and I printed the Buddy test print and it came out beautifully.
Thanks for your help!
Re: Width of extruded filament reduced
Tuning the Zheight made all of the difference!
It's amazing how many problems can be solved by tuning the Z height, tightening the set screws on the pulleys, and updating to the latest firmware.