Extruder teardown: Did I miss anything?
After 18 months and dozens of nozzle swaps, my heater block finally stripped out. On inspection, it was pretty clear that my early learning experiences had made a mess of the block and anything attached to it. I decided to tear down my OG Mk3 (pre-S, R2 parts) and do a bit of an overhaul.
- Replaced heater block with E3D nickel-lated copper version. I'm hoping the higher temps of copper will resist stripping after repeated nozzle swaps at 285C. Must also pay attention when swapping nozzles!
- Replaced heatbreak with E3D titanium version. Not absolutely necessary, but I figured it was a good opportunity to do it.
- Replaced heater cartridge as original was badly gunked up. (I did manage to salvage it in the end.)
- Replaced thermistor as original was permanently encased in crud.
- Replaced spiral cable wrap with mesh loom.
- Applied Arctic MX-4 thermal compound between heatbreak and heatsink per E3D instructions.
- Applied Slice Engineering Boron Nitride thermal paste to thermistor and heater cartridge in hopes they'll be more easily removed.
- Fresh silicone sock and cleaned nozzle.
Thinking about it afterwards, I probably should have done some PM replacements:
- Replace PTFE tubing. It's a bit gnarly but the original is still working.
- Replaced part cooling fan. It's gotten a little loud. I've been eying the recommended Sunon replacements.
- Replace hotend cooling fan. I'm not really having any cooling problems with the Noctua, even with my R2 parts, but the Sunon replacement sounds promising.
I've got some spares in the box for next time:
- Aluminum E3D heater block.
- E3D heatbreak (Prusa and non-Prusa versions).
- Thermistor.
- Heater cartridge.
I'm staying with my R2 PETG printed extruder parts as cooling has not been an issue for me and the various PINDA sag issues have made me wary. I'll likely go with @guy-k2's bunnies version when the time comes.
I don't expect to do this again anytime soon, but I want to keep notes on the process to speed things along.
- Did I miss any opportunities?
- Has anybody done a quick-release for the thermistor and heater cartridge that would avoid the need to re-do all the wiring back to the control board? That was a real pain.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan
RE: Extruder teardown: Did I miss anything?
Sounds good Bob. I’ve been planning on doing mine at some point when I need to, ie when it stops working so well.
im planning on putting connectors into all the wiring so that future swaps are easier and I also bought a new set of bearings and rods in case I need them. Unfortunately I didn’t grease them when I built mine as the manual made no mention of that so I’ve been oiling in the mean time until I have to do the tear down.
I've got a butterworth on there at the moment and have printed out a slightly modded version of Guys geared Bunny version to still use the mk3 sensor and bearing but I also have more adjustable x axis ready too.
Hadn't thought about replacing any of the hot end but now you mention it 😀
RE: Extruder teardown: Did I miss anything?
Bearings and rods are on my "todo" list, but no urgency. I think that one will take me offline for a bit longer. Going to do a bit more research before trying that or any major extruder changes.
I'm really curious why Prusa doesn't use the short modular E3D cables for the heater cartridge and thermistor. Those long cables turn what should have been a relatively short procedure into a bit of an adventure. I also think modular plugs would ease overall maintenance.
and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan