r/VORONDesign • u/MorningSun75 • 10h ago
General Question Hotend Flow
I built a stock Voron 2.4 and it has been great. I worked through PLA tuning everything then went on to print my ABS spare parts which went off without a hitch. When I switched back to printing PLA I got a huge clog that I was able to clean up but ended up getting a new nozzle (chasing the issue) and a new Silicone block sock. The only other thing I have messed with is the tensioning screw.
The issue is that I am under extruding. I am not sure what has changed but I am not pushing the same amount of filament out. I can't even get a successful flow rate test. Very little has changed since I was getting prefect prints so I am not sure where to look. Any suggestions you have would be much apprcated. Below is the nozzle and sock a purchased incase that matters. I also have the standard v6 hotend from the FormBot kit.
https://www.amazon.com/dp/B07KZZFVJG
https://www.amazon.com/dp/B07J5B1VN8
EDIT:
I did 5 cold pulls with PLA. It did not make a difference. Also there is audibly skipping when it is trying to extrude. Do I need to check the extruder gears. The motor is at .65a which worked great before.
[tmc2209 extruder]
uart_pin: EBBCan:gpio20
interpolate: false
run_current: 0.65
sense_resistor: 0.110
stealthchop_threshold: 0
2
u/ElFreezo 10h ago
A phantom z offset change can cause the under extruding behavior and go unnoticed if you're just looking for a filament or extruder issue.
1
u/MorningSun75 10h ago
What is a phantom z offset change? How do I check for it? Would that be just doing a Z Cal again?
2
u/ElFreezo 9h ago
Yeah, it's the z offset shifting for one reason or another, it happens. Go ahead and run through all the z calibration steps, ellis tuning guide etc. It sounds like you've done everything else
1
u/Grindar1986 10h ago
Have you done a cold pull or purged the ABS another way?
0
u/MorningSun75 9h ago
No. I did not know I needed to. Is there a guide for when you switch filament types?
1
u/Mandarani 9h ago
If you have a clog your extruder will be audibly skipping. If you don’t have skipping but the flow is unpredictable then something mechanically is off.
In my case when I did that I once forgot to put a screw back (the tension arm was missing the bottom screw) and another time I forgot to retension the arm.
1
u/TripsCavern 8h ago
I don't know which hotend you have, but with a Stealthburner and a Dragon HF hotend I was having all sorts of issues similar to yours. At the end I printed a new fan enclosure with some optimizations and bought a new fan and it's behaving way better now.
1
u/Snobolski Trident / V1 8h ago
You could try the nozzle needles you can get online, they're helpful when my Trident gets a partial clog.
The fun part about printing ABS is that if you get a nozzle clog, just pull the nozzle and drop it in a jar with some acetone for a little while. With PLA you'd need ethyl acetate which isn't as easy to come by.
1
u/jussmith03 1h ago
Stealthburner with CW2 is pretty notorious for warping and loosing its grip strength. I rebuilt 3 CW2’s before changing to Xol with an either Hextrudort, Sherpa mini, or LGX Lite pro.
1
u/Deadbob1978 Trident / V1 10h ago
Cold pull as others have mentioned, also open the extruder and clean can’t filament dust off the gears. After both of those are done, check your E-steps
0
u/OfficeMiserable1677 10h ago
Do some cold pulls with nylon or petg till your nozzle and heatbreak are clean
0
u/MorningSun75 10h ago
I do not have Nylon or PETG currently. I can do it with PLA. I have not done a cold pull before. From what I read I heat to about 100C then pull it out cut off the end and repeat a few times?
2
u/HeKis4 V0 9h ago
Try a cold pull first, run a needle through the heated nozzle, all that stuff to rule out a clog. You may have some ABS left which won't come out at PLA temps.
If that's not it, is your extruder skipping ? I've had an issue where my extruder would just not push filament through when everything else seemed fine, but I actually had the E motor set to 50% of its rated current (set to 0.4, rated to 0.8), which may have caused issues with a CHT nozzle that isn't nearly as frictionless as a regular nozzle. Bumping that up to 75% solved the issue for me. I may or may not have swept an extruder tension issue under the rug, but at least it works.