Hi, I installed an E3D V6 hotend this last week, and wanted to share my experience. I avoided any adjustments to the firmware.
Mount: I’d recommend printing a mount. The ichbinsnur mount for printing flexible filament looks good. I didn’t print a mount, because the printer’s extruder wasn’t functional. Instead I made an aluminum plate, like the stock velleman extruder attaches with, just with a smaller hole for the E3D’s heatbreak to poke through. I don’t recommend this, if you can print a mount. The thickness of the new plate gets into the area of the E3D’s heat break, and I was concerned about heat wicking up into the first fin of the heatsink. Also the long coupling nuts that the M3 screws thread into don’t quite clear the blue plastic fan attachment, that holds the new fan that blows on the heat sink fins. I kinda bent my screws a little bit. It fits, but isn’t pretty… Lastly, the E3D is shorter than the velleman extruder, which brought up an unforeseen issue: the metal of the Z carriage will collide with the Z endstop switch, before the extruder gets close to the heated bed. I got around this by drilling a new hole, lower, in the Z motor bracket, for the Z endstop switch, and moving it down, so I could lower the Z endstop screw, and hit the switch with the screw, before the Z carriage hit the switch. This issue would be avoided, by one of the printed mounts, because it would hang the extruder down lower, closer to how low the stock extruder was.
Thermistor:
I had a replacement velleman 100K thermistor, so I used that, rather than the E3D one that came with the kit. I recommend using the velleman thermistor. It was nice having a new one, because the hole for the E3D thermistor, in the heater block, is deeper than Velleman’s. It was difficult to stuff the original thermistor down in the hole, with the solder joints right there. It was much better to use the new velleman thermistor, because the legs could be left long, to clear the hole, and the clamping screw, before making the solder joint with the wires. I used the little, woven insulation that came with the E3D, to insulate the thermistor legs from shorting out on things. The velleman insulation is too big of a diameter to easily fit down in the hole in the E3D’s heater block.
I don’t know the specs of the E3D’s thermistor, but unless it is identical, I’d just buy a new velleman thermistor, rather than spending a bunch of time messing with firmware.
Heater Cartridge:
I disagree that the E3D heater cartridge is a drop in replacement, to use with the K8200, without limiting its current in the firmware. It will draw significantly more at 15v than it or the K8200 is designed for. It is a 12v, 30 watt, 4.8ohm heater cartridge (the Velleman is 15v, 33 watt, 6.8ohm). Ohm’s law shows running the E3D on the higher 15v will draw 46.8 watts:
Volts/Resistance = Amperage
15v/4.8 ohms = 3.125 Amps
and then, Volts*Amps= watts
so, 3.125amps * 15v = 46.875 Watts.
I opted for removing my velleman heater cartridge, even though it was glued in. I scraped off the red glue, and then, because it was pressed into the heater block, I used a vice, and hammer to pound it out. I used a #10 machine screw, because it was a little less in diameter than the heater cartridge, as a drift. I filed the end in a dome shape to kind of match the dimpled end of the velleman heater cartridge.
I just didn’t feel like the E3D heater was the right part to use, no way around it. Any time it is getting the full 15v, it is drawing more than it or the system was designed for. If you do use the E3D, 12v 30 watt cartridge, and want to run it at 30 watts, you would want to dial down the current setting in firmware to be 170 ( 30 watts is 64% of 46.875 watts, so 170 is 64% of 256). I’m not sure though, if it does a pwm thing when it is heating up, or just switches on the 15v til it gets hot. It just seemed simpler to use the correctly rated part, the velleman heater, rather than having to screw with the firmware to get a less suited part to work.
PID:
After getting it together I ran the PID and entered the numbers into the eeprom, and have gotten much more stable temperature. Took 10 minutes and was simple to do. Highly recommended.
Too early to say what the benefits of the E3D are. I have some calibration issues to work out with the machine, but it does seem nice having an extruder that needs less retraction to not ooze, and am not getting the constant jamming issues that developed with my original extruder. Seems like I’m able to print pretty fast, too, once the first layer is down.
EDIT: forgot about the new hotend fan.
FAN:
Because the fan is 12v, and the K8200 power is, again, 15v, I needed to drop the voltage seen at the fan to around 12 volts. I used a 3v, 1 watt Zener diode (actually 3.3v, because that was what was around). It is reversed biased (cathode to the (+), the controller board, and anode to the fan (+) red wire. Fan black wire to ground. The fan is always on, when the printer is powered. Why a zener diode, rather than a resistor? I had some, and felt like the regulation would be better (the fan sees a more constant voltage). Not sure it makes a big difference. The 37 ohm resistor people mention is probably just fine, if that is what is available.
Hint: If you don’t feel like running new wires from the board to your fan, there is already +15v going to one side of the extruder heater cartridge; the controller board switches the ground connection off and on, to regulate the heater, the (+) side is always connected to +15v. There is a ground connection at the extruder too, one of the thermistor wires. Not sure which color wires in the ribbon cable are which, sorry, I would say just beep it with a multimeter, back to the power supply + and - input terminals. One trick is to stick a sewing needle through the wire insulation, to beep the wire inside, so you don’t have to undo and redo the heatshrink.
The fan draws 95 mA.
