Hi, I fitted a K8203 extruder to my printer, I altered the line of code from true to false to make it go the right way (should it not go the correct way as that is how they instruct you to build it), anyway, it prints fine but every now and then it “kicks” back and neither feeds nor retracts just makes a clunking noise, if I force the filament in it feeds fine…what’s going on…help please
Check the drive pulley for alignment.
Make sure the set screw is tight.
I have the same problem. I have tried aligning the pulley by rotating it a little with the setscrew loose, then tightening the screw.
I read elsewhere that it’s important to cool the plastic barrel with the fan, so that the filament doesn’t stick or swell in the guide.
I’m still struggling, but I melted the nozzle off of the barrel (!?!), so I need to get a replacement before I can do more trial and success.
I note that the heavy pressure against the hobbed pulley scores the filament. I’m interested in adjusting that somehow. Perhaps a shorter spring/washer/nut/bolt assembly.
I found this in the instructions for the K8203.
Take the STEPPER MOTOR from the old extruder body and place the FILAMENT PULLEY on the shaft, make sure the pulley sits 8.75mm from the top of the shaft. Tighten the pulley on the shaft with an M3 x 4mm SET SCREW.
You can find the instructions here
http://manuals.velleman.eu/article.php?id=357
many thanks to everyone for there help, I managed to trace the problem to the replacement motor driver board, the board is not at fault but it did need the voltage trimming in a similar fashion as you have to do with a new build using a multimeter
What did you set the voltage to? 0.55VDC?
For the K8203 it needs to be set to 0.8
Would you happen to know the steps/mm? I read 75 is a good place to start, and it jives with my math.
I just finished the install of K8203.
Some things I noticed:
- Extruder ran backwards in left hand mount
- The PLA default file wouldn’t load into slic3r versions cited. I wound up reverting to the 3mm PLA file and making the changes for 1.75.
- I used a continuous fan on the isolator, connected to the 12vdc output for the LCD plug
- The hot end wouldn’t make temp without a ceramic blanket to isolate the thermistor from the fan.
- I used a second, software controlled fan for printed parts
- Extruder is a pain to load filament into. The holes are inaccessable without removing the filament tensioner to line the filament to the hole in the base of the mount. This hole could really use a countersink.
- They changed the PID values in the default EEPROM load, and I don’t know why.
- The steps/mm is 150 in EEPROM, if you want to skip reloading Marlin.
- The stepper driver wants a 5mm heat sink, so I put one on.
- The stepper driver was set to .9VDC when installed, I adjusted it to .8 per Wrongway’s guidance
I do, however, like the print quality. It took 5 iterations of cal cubes to get it right, but this last one is my best ever.
Hi, I didn’t have any of those problems except filament going back wards but you can fix that by altering one line of code, I finally traced the problem not to code or driver voltage but the fact that the filament is hydroscopic, the filament comes sealed in a bag with a desiccant bag to absorb the moisture, I haven’t been keeping the filament in a dry or heated storage container, when the filament enters the extruder the moisture builds up and turns to steam…this pressure causes the filament to be “kicked back” and so doesn’t extrude at that point, I slowed all the print speeds to 20mm and bed temp to 55c and print temp to 190c, touch wood since then I haven’t had any problems with kick back, but I plan to buy or make a heated storage cupboard to keep the filament in
Here’s my first test print using the K8203:
http://www.thingiverse.com/make:186735 at 1mm layer height, 75% speed, 197C Hotend, 50C bed (based one Default firmware and 3mm PLA profile from Velleman)
There’s also a timelapse video with Octopi I uploaded with the pictures.
I’ve got some work to do, as the banding is actually worse now than with the 3mm nozzle. I’m waiting on screws to install ichbinsnur’s dual-z leadscrew kit, I think that will solve some of it.
The cantilevered z arm has so much play, and I’ve gone and added a cable chain loaded up with the ribbon, 2 x usb cables, the LED power cord, and an additional 2-wire power lead for the continuous isolator fan. I think it’s fighting the z moves as a result.
Any tips/tricks to knock down the lines would be greatly appreciated!
Hi, I would remove the energy chain and ensure there is plenty of slack in the cables, I set my first layer height to 0.3mm and all other layers to 0.23, I set most of my speeds to 20mm except bridge and max speeds, flow ratio to 1 and filament diameter to 1.75 but extrusion multiplier to 0.9, I also set my extruder temp to 190c and bed temp to 53c, the quality of the prints I get are fairly good, I also use double sided sticky tape on the glass bed or masking tape and rough it up with sand paper, it’s easy enough to get the prints off by just letting the glass plate soak in warm water…(I have 2 glass beds and just keep swapping them)
regards
rogueisland
[quote=“rogueisland”]Hi, I would remove the energy chain and ensure there is plenty of slack in the cables, I set my first layer height to 0.3mm and all other layers to 0.23, I set most of my speeds to 20mm except bridge and max speeds, flow ratio to 1 and filament diameter to 1.75 but extrusion multiplier to 0.9, I also set my extruder temp to 190c and bed temp to 53c, the quality of the prints I get are fairly good, I also use double sided sticky tape on the glass bed or masking tape and rough it up with sand paper, it’s easy enough to get the prints off by just letting the glass plate soak in warm water…(I have 2 glass beds and just keep swapping them)
regards
rogueisland[/quote]
You’re onto something with your layer height choices. It looks like the majority of the banding is stemming from the .1mm layer height I chose. The Z-axis, between the 1/32 stepper and the K8204 leadscrew, has a resolution of 15 (0.0150000234375366) microns to get whole steps for every layer adjustment. I printed a 25mm cal cube using the same hardware, filament, humidity, temperature, and print settings at .09 layer height and the banding is 70% resolved. Chalk it up to float, rounding, and microsteps.
I think what’s happened is that I normally printed in .25 layer height with the stock extruder, and with the .35 I worked up the nerve to chase <.1. .25 layer height was closer to the needed .255, and the larger extrusion helped to mask the error in the steps.
Hello again, I forgot to mention that I also set my nozzle diameter to 0.3mm…not 0.35, this setting is in slicr configuration…printer settings…happy printing