Repair/replace/upgrade of MK3 extruder assembly
Got an extruder jam on my MK3 when printing face shield frames during COVID. Had to disassemble the extruder assembly to clear the jam, but two of the screws could not be removed. (The lower left part in the picture.) Did not have time, so put the MK3 aside.
More recently bought the upgrade kit to MK3.5S. So far as I can tell the E-Axis assembly is unchanged from MK3. (Original parts have the "C1" mark.) Currently printing the E-Axis parts from the "i3 MK3S+ printable parts" on Printables. (Hopefully I have enough spares or equivalents to the odd-sized screws.)
Printing the entire set, as I do not know if there are any changes in design from "C1".
Tempted to print the MK4 "Nextruder" parts, since I am re-building the extruder, but suspect that would not work out well.
Looking for a sanity check. Is there another alternative that makes more sense, given I have to re-build the extruder assembly?
Best Answer by Preston L. Bannister:
Seems we should be oiling the screws used in assembly. After ripping apart the x-carriage, I needed two vice-grips to unscrew the stuck square nuts, ruining both parts. Apparently they corroded together. Which is why I ended up needing to rebuild the extruder assembly.
What I needed to know...
If you have to rebuild the E-Axis assembly on the MK3 to MK3.5 then print the "E-Axis" parts from:
MK3+ printable parts
Note the design has changed slightly, so you need to print pretty much the full set of "E-Axis" parts.
You can use the instructions in:
MK3S E-axis assembly
This means the parts will have small differences from what is shown in the instructions.
Got most of the way there. Ran out of square nuts, so waiting on a delivery.
RE: Repair/replace/upgrade of MK3 extruder assembly
Friend has a Core one. Nextruder is very different. I am upgrading to 3.5 shortly and changing to a REVO hotend from so many comments on this forum. Search for comments on the REVO. It looks like the REVO may just plug into the Mk3 printed parts.
RE: Repair/replace/upgrade of MK3 extruder assembly
Unless you had the MK3 to 3.9 or 4 upgrade kit, I would skip on printing those parts since the 3.5 uses the v6 hotend 🙂
Shane (AKA FromPrusa)
RE: Repair/replace/upgrade of MK3 extruder assembly
Right. Hotend changed. I knew that ... or should have (have a MK4 also). :/
RE: Repair/replace/upgrade of MK3 extruder assembly
Seems we should be oiling the screws used in assembly. After ripping apart the x-carriage, I needed two vice-grips to unscrew the stuck square nuts, ruining both parts. Apparently they corroded together. Which is why I ended up needing to rebuild the extruder assembly.
What I needed to know...
If you have to rebuild the E-Axis assembly on the MK3 to MK3.5 then print the "E-Axis" parts from:
MK3+ printable parts
Note the design has changed slightly, so you need to print pretty much the full set of "E-Axis" parts.
You can use the instructions in:
MK3S E-axis assembly
This means the parts will have small differences from what is shown in the instructions.
Got most of the way there. Ran out of square nuts, so waiting on a delivery.
RE: Repair/replace/upgrade of MK3 extruder assembly
Stainless steel shouldn't corrode. Not a mech engineer but a friend of mine told me the other day that if stainless steel spalls, it will stick like glue. Never run into that problem myself. I would use some synthetic grease instead of any oil.
For my MK3s+ when the head melted the parts, I had already printed the replacement parts in ASA. Now all my printed parts are in ASA.
Recently I went through all the MK4 parts or MK3 parts that are based on stronger and better MK4 parts and upgraded them on my printer with ASA printed parts. Stiffer and better heat resistance. I have noticed that there is less vibration on all the parts. Easier to adjust the X and Y axis belt tension with the new designs. When my hotend failed, it did melt some of the ASA printed cooling parts. At least I was watching the printer at that time. It was before the thermal shutdown model in the firmware.
I need to print the 3.0 to 3.5 upgrade parts and need to calibrate the ASA that I have. Also want to look to see if there is a different design for the hotend as the REVO has a notch in to stop rotation. May modify a file to print an improved part to hold the hotend.
RE: Repair/replace/upgrade of MK3 extruder assembly
Got the MK3 re-assembled and working. Stayed with the stock (but updated from original) E-Axis assembly.
Have the upgrade kit to MK3.5S, and will install next. That gets stock wireless, and a bump in performance. (Originally got wireless using OctoPi.) Otherwise likely will not do any further upgrades to this printer. (Have a couple of Voron kits to build, and looking forward to Bondtech's INDX.)
RE: Repair/replace/upgrade of MK3 extruder assembly
I was talking to someone the other day. Have some clear ABS and clear PC filament. May learn to print the 3.5s head/REVO head pieces in clear, for the effect. Just a weird thought. 3D printing should be fun at times.
RE: Repair/replace/upgrade of MK3 extruder assembly
I might agree. 🙂
Had a spool of "silk" blue PETG on hand, and used to print a set of parts (as called for in the directions), before realizing the upgrade kit included those parts. :/
Turns out, the printable parts are a slightly later revision than those included in the kit, so I can rationalize the waste.
Also ... kinda like this blue ...
RE: Repair/replace/upgrade of MK3 extruder assembly
The blue looks nice. I want my head pieces out of ASA or some other high temp material. I have already melted one PETG head.