Using the original motor, with two #6 washers stacked. Couldn't hold the washers in place with tape (the collar pushed the tape down, taking the washers with it), so I put the collar on the motor axle, held it horizontally, then slid one washer in, then pressed the second one on top of the first with a screwdriver and hammered the collar down over the second washer. It sticks out a bit, but it's jammed in solidly and, most importantly, works.

No luck with the new motor. The pins ended up in the corner of the collar's square opening, with the motor axle turning, gradually wearing the pins flat. One washer in simple bent. Two washers didn't fit.

Perhaps a collar with a set-screw might work? The other thought I had is to grind the motor axle down to be more flat, so there's more surface to work with (and to transmit the torque). I might try that some time - I have an oscillating tool that might theoretically be able to affect the steel shaft. Or whatever that axle is - it's tough!

When you were extruding, at what speed was the extrusion occurring?

Forgot to answer this one.

When the washers were working, extrusion was at the speeds people have described, slow but visible motion. extruding a few yards in a few hours, using the original motor.

When the pin was working, it extruded a few inches in a few minutes, so around the above speeds. This was with the new motor.

When the pins were partially working, it was much, much slower, because the feed screw would engage the pin turn perhaps half way then slip for a while, then turn a bit the next time it came to the pin. Given that the motor sounded like it was running fine (speed up and slowing down perhaps every 10-15 seconds), if I hadn't removed the top piece and watched it in motion, I'd have thought everything was fine and I was mysteriously getting slow extrusion, when it was the axle slipping.

I haven't run with the side panel off - I think that would cause the machine to self-destruct from torque. The assembled unit doesn't have a solid base, so it's really twisty with the side panels off. That being said, I have been running with the back top piece off, so that I can see what the motor assembly is doing. With screws at top and bottom of all of the vertical boards, the whole "box" seems fairly stable even with that one piece missing.

One suggestion - next time you make complete assembled kits, see if you can make the bottom a solid piece of wood, so the case isn't "structural". That would make it much easier to tweak, since you could leave it "open" until it's working right, then close it up to look nice. As it is, I have to open it up, tweak, reassemble it, then run it to see what happens. I will say, having disassembled/reassembled the case, it's great that all of the screws go into metal threads - very nice touch!

I haven't had problems as many problems with it as you and a few others seem to be having. I want to make the coupling robust but also allow for misalignment, and that seems to be a challenge thus far, especially when they work for me.

When you were extruding, at what speed was the extrusion occurring? You have not ever run the extruder with a side panel off, correct?

As a separate issue, I'm having trouble ever since I swapped the original motor for the newer/faster one. In swapping the motors, the washers were crushed, so I switched to the 3/32" pin that Elmoret sent (thanks!). Unfortunately, the pins didn't work for long. I noticed that the motor axles for the two motors are different - the "flat" on the old motor is much larger than the "flat" on the new motor, which is very nearly round. I also noticed that the pins are quite loose between the motor axle and the square end of the hex socket. Perhaps because of this, the pins didn't work with the new motor - after making it around one or two times, they basically rolled around the motor axle and wore down.

Tomorrow's trip to the hardware store I think I'll try one size larger (1/8") to see if that fits more tightly.

I suspect that the underlying issue is a blockage, and hopefully I can get the nozzle off and clear that out. Because "let it soak up heat, then push it through" isn't working.

Forgot to attach the photo. The two axles look like the same diameter, but the "flat" on the old motor looks much deeper than on the new one.

And the various things crushed trying to turn the feed screw. Not too useful a picture, perhaps, but I found it amusing. That's a pretty strong motor, and/or pretty stubborn plastic.

I tried going back to the old motor, but the pines were even looser, perhaps because they were worn down. So no luck there.

The part that's a little odd to me is that before the pins gave out, they did make it around a few times, and plastic was extruding. So it's not completely blocked, just "slow".

Suggestions?

I'll give it another shot tomorrow, thanks!

Tomorrow's trip to the hardware store I think I'll try one size larger (1/8") to see if that fits more tightly.

I suspect that the underlying issue is a blockage, and hopefully I can get the nozzle off and clear that out. Because "let it soak up heat, then push it through" isn't working.

Oh, I can swap nozzles in under 5 minutes. Hot ABS doesn't flow like you think it does.

1.) Heat to 180C
2.) Power off, remove thermocouple and back nozzle out 1/2 turn
3.) Loosen nozzle 1/2 turn every 60 seconds until free
4.) Install nozzle and thermocouple
5.) Heat up to 180C
6.) Ensure nozzle is tight (usually takes 1/2 turn here)

If you're worried about ABS flowing out  of the nozzle, just turn the extruder on its back, so it is sitting on the motor mount. Then gravity will keep the ABS in.

Am having trouble doing the above, specifically I can't get the nozzle to turn off of the larger, short pipe that it's screwed into. Instead, the short pipe (with the heater) unscrews from the long pipe that runs back to where the plastic feeds in. The challenge, I think, is that there's nothing to grip on the short pipe, so while the wrench turns the hexagonal nozzle just fine, the pipe turns freely, and there's apparently more friction in the threads between the nozzle and the short pipe than between the short pipe and the long one.

Any suggestions for how to get the nozzle to unscrew instead of the short pipe? Is there a kind of wrench that's more gripping on a steel pipe?

Oh, I can swap nozzles in under 5 minutes. Hot ABS doesn't flow like you think it does.

1.) Heat to 180C
2.) Power off, remove thermocouple and back nozzle out 1/2 turn
3.) Loosen nozzle 1/2 turn every 60 seconds until free
4.) Install nozzle and thermocouple
5.) Heat up to 180C
6.) Ensure nozzle is tight (usually takes 1/2 turn here)

If you're worried about ABS flowing out  of the nozzle, just turn the extruder on its back, so it is sitting on the motor mount. Then gravity will keep the ABS in.

where is the like button. lol

1.) Heat to 180C
2.) Power off, remove thermocouple and back nozzle out 1/2 turn
3.) Loosen nozzle 1/2 turn every 60 seconds until free
4.) Install nozzle and thermocouple
5.) Heat up to 180C
6.) Ensure nozzle is tight (usually takes 1/2 turn here)

If you're worried about ABS flowing out  of the nozzle, just turn the extruder on its back, so it is sitting on the motor mount. Then gravity will keep the ABS in.

RavensCrest wrote:

diassemble is going to be a b*tch

It really isn't that bad.

New motor is the same exact mounting pattern. Pull the two screws out from the base, slide the motor off the feedscrew, swap the mount and coupling to the new motor, reinstall. I've swapped motors in 10 minutes. No more difficult than a jigsaw swap, that's for sure.

was thinking about installing the filter...
In my mind, I can picture as soon as unscrewing the nozzle.. Hot ABS will be pouring down you leg... and pipe thread will be filled with abs and you won't be able to screw the nozzle back... :-(

diassemble is going to be a b*tch

It really isn't that bad.

New motor is the same exact mounting pattern. Pull the two screws out from the base, slide the motor off the feedscrew, swap the mount and coupling to the new motor, reinstall. I've swapped motors in 10 minutes. No more difficult than a jigsaw swap, that's for sure.