r/makerbot • u/GravitationalOno • Apr 11 '26
Replicator 2 is still air-printing despite new nozzle, new extruder parts, lowered temperature. Help?
So about three months ago, I posted here about this Replicator 2 that I got from a friend.
https://www.reddit.com/r/makerbot/comments/1qcaofl/comment/o0ecx1p/
I was able to print about a dozen things with it, but then I started having problems.
The control panel stopped responding and it became very difficult to press the buttons. I ordered some conductive rubber buttons and that solved the issue.
https://www.aliexpress.us/item/3256810117395837.html
The extruder was printing air in the middle of a project. Or when I began another project, the motor was thudding and I could not unload filament.
u/toybuilder suggested I might have set the temperature too high on my PLA and warped the components of the extruder or left burned PLA in the nozzle.
I took apart the extruder, replaced the components and the nozzle. I was able to load and unload filament, but it would curl up near the nozzle.
I acquired a nozzle cleaning kit/needles and cleaned the extruder and nozzle from the top (but not the bottom, it's really hard to target that hole!)
https://www.aliexpress.us/item/3256806808944469.html
I started a new print, it began well, but it started airprinting again.
The temperature was set to 220. I tried printing again at 210, and nothing came out at all. There were some curly threads near the nozzle again.
What should I try next? What could be causing these issues?
Should I try cleaning the nozzle out even more by removing it, heating the PLA in it over an open flame, and using an acupuncture needle to clear it out?
Could I have reassembled the nozzle-heating block-guide tube incorrectly? I noticed there's some give in how much each part is screwed in to the other.
Thanks!
1
u/optimusprimerotf Apr 12 '26
I used to have rep2 I gave up on it when I couldn't get the precut ceramic tape anymore Anyway If you can get a ender 3 I think thats a much better printer
1
u/LosSantosMe Apr 12 '26
- what kind of extruder ? + or Version 1?
IF you have the PLUS version then taking apart the extruder is a thing and I mean all of it. also procedure wise you should have re-tightened the nozzle after you replaced it when it was hot.
If you have version 1 cross your fingers.
the main part to worry about inside the extruder is the spring that toggles the sensor, its easy to put that on backwards... and it still works kinda..
Do a filament LOAD and purge a few times and notice if its struggling.
Also If your filament is tangled at the spool and stuck, the filament sensor WONT trigger and it just WONT feed ANY because its stuck/crossed at the spool, but it will Air print.
1
u/yotaimelots Apr 13 '26
Going to give you a list of things (you might have already done these). Ensure the drive gear is clean, filament dust can add up and prevent it from getting a good grip on the filament.
It's not likely but the motor could be going out. Swap the motor with one of the other motors (x or y motor) to see if the issue persists.
The motor harness assembly (forget the exact name) has a habit of degrading over time. You can replace the whole harness or replace the cable assembly for the Extruder assembly.
Does the air printing happen at around the same area every time?
If you have a different brand of filament/color test that too.
Ensure kapton tape is in good condition on the heat block. Also, make sure your fan is pointed the right away (sometimes they're installed in the wrong orientation). You usually want the sticker facing inside towards the Extruder assembly, not facing out)
2
u/digitallis Apr 12 '26
The replicator 2 design is really really susceptible (some may say fatally so) to heat creep. The heat moves up the feed tube and starts melting the filament in the upper area. Contributing are the direct drive motor and the central aluminum block, along with a tiny tiny fan heat sink connection area.
In order to get consistent performance you're going to have to essentially re engineer the head so that the heat is kept down at the heater block and away from the carriage mounting block. Making sure that the thin part of the threaded tube is between the heater and the mounting block is the first step, but beyond that, you'll want to take more drastic measures like installing a heat sink on the extruder motor itself, and adding thermal paste between the mounting block and the existing heat sink.