Just pulled off a 3d printing ninja move, figured there may be some appreciation here for it.
Printer A has spool holder that is a horizontal metal rod about 3/4" across with a big plastic nut on the end: I have a 3kg spool on it (printing big things with 1.2mm volcano nozzle), and the weight is enough to make it walk into the nut as it spins… and it turns the same direction as to loosen the nut… so I have to put a piece of tape on the nut to hold the nut in place.
But last time I changed filaments I forgot the tape… and last night the friction spun the nut off, the spool fell out, but just barely held onto the end of the rod… and the Bondtech extruder was strong enough to keep it turning (yet didn’t fall off all the way somehow), so I didn’t loose the print, which is amazing. But I can’t find the nut.
Today I go to start another print, completely forgetting the nut is missing :-S
3 minutes later: ‘crash’: the spool falls off, but again, the rod it’s on just catches it, hanging there. I shove it back on, but I can physically see it walking off the rod as it turns. What to do? I really want this 17 hour print to finish tonight…
I have another printer: So while printer A is running (and as I constantly shove the spool back on the rod), I measure the width of the threads, model up a nut in Maya, and print it out on printer B (6 minutes). Screws right on, and it’s been re-taped.
Use some plumbers tape PTFE and wrap the male threads a couple times to make the threads larger and consequently making the nut harder to turn loose.
Simple $2 solution. You probably have some in your toolbox already.
As a slightly different approach to that suggested by @Dan_Ghiciulescu , turn the threaded rod around so that the reel “walks” the other way - this’ll allow you to keep it threading in from the left. You could also print a smooth tube to cover the thread itself to avoid the walking issue, especially if you print a flange at the nut end.
Thanks for the thoughts everyone
I can’t turn the holder around 180, it would make it really hard to get the spool on, based on how I have it mounted on my shelf. The new nut I printed fits on way tighter than the ‘real’ one (since it has no threads), so I don’t have a lot of concern of it spinning off… but I still use tape just in case In hindsight, plumbers tape would have done the same job on the old nut… that yah, may actually be inside my other print, the infill is pretty light Not enough room on the threads for two nuts, but that’s a good idea too.
Mainly I was just proud that I fixed printerB with printerA while printerB was running
A bracket to support the nut end of the rod so it doesn’t sag would solve the problem, you could attach it to a hinge so it can be moved out of the way to load filament reels.
I would still lock the nut somehow though.
Not enough room on the threads for two nuts, but that’s a good idea too.