Something wobbling.
Posted by SupraGuy
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Something wobbling. September 14, 2018 01:00PM |
I seem to have developed a problem. I'm still troubleshooting it, but the printer isn't printing straight on top of the last layer. the hot end seems to be solidly mounted:
That's a modification to a bowden extruder to make it direct mount. The brass piece is a 1/4" NPT thread to hose barb fitting. I ran the barbed hose fitting through a 6mm thread die so that it threads into the extruder, and the 1/4" NPT fitting is close enough for the 1/4" BSPT thread in the heat sink for my E3D V6 clone hotend. (The difference between NPT and BSPT is the angle that the threads are cut at, BSPT is cut with the threads at 55 degrees, NPT is at 60 degrees, so mixing the fittings like that results in something that isn't going to be water tight, but it will be more than secure enough to provide mechanical security.) I put a flanged nut in between the NPT fitting and the bottom of the extruder to keep things tight and square. There is no visible wobble there. Actually, I like this as a mount.
The smooth rods are nice and tight in the towers, it doesn't look like Z wobble, though I think I may need to take some measures to make sure that it doesn't become a problem, but it's completely overshadowed by whatever is happening now.
I thought I had a picture of the print, but apparently it's not on my phone. Weird.
Anyway, I'll be looking at the bed for sources where it might wobble, and checking that the smooth rods are in nice and tight with no play next. I got a couple of very nice prints off, but the last thing I tried to print was awful. Well, I had also just tried printing a large fan grill (230mm fan) with lots and lots of little hexagons, so that might have rattled something loose. The frame still feels solid, but I guess I'm looking for something that's wobbling maybe a half milimeter or so.
MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.
Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts
That's a modification to a bowden extruder to make it direct mount. The brass piece is a 1/4" NPT thread to hose barb fitting. I ran the barbed hose fitting through a 6mm thread die so that it threads into the extruder, and the 1/4" NPT fitting is close enough for the 1/4" BSPT thread in the heat sink for my E3D V6 clone hotend. (The difference between NPT and BSPT is the angle that the threads are cut at, BSPT is cut with the threads at 55 degrees, NPT is at 60 degrees, so mixing the fittings like that results in something that isn't going to be water tight, but it will be more than secure enough to provide mechanical security.) I put a flanged nut in between the NPT fitting and the bottom of the extruder to keep things tight and square. There is no visible wobble there. Actually, I like this as a mount.
The smooth rods are nice and tight in the towers, it doesn't look like Z wobble, though I think I may need to take some measures to make sure that it doesn't become a problem, but it's completely overshadowed by whatever is happening now.
I thought I had a picture of the print, but apparently it's not on my phone. Weird.
Anyway, I'll be looking at the bed for sources where it might wobble, and checking that the smooth rods are in nice and tight with no play next. I got a couple of very nice prints off, but the last thing I tried to print was awful. Well, I had also just tried printing a large fan grill (230mm fan) with lots and lots of little hexagons, so that might have rattled something loose. The frame still feels solid, but I guess I'm looking for something that's wobbling maybe a half milimeter or so.
MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.
Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts
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Re: Something wobbling. September 16, 2018 10:21PM |
How is the heatsink held in place chewing gum 
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Re: Something wobbling. October 03, 2018 12:34PM |
I didn't have a good photo handy, but this is what was going on.
I have since got that cleared up, though I'm not entirely sure where it was. I then had some actual Z wobble (Present in the blue vase print, kind of hard to see in this photo) There were ridges which exactly lined up with the threads in my 5mm rods visible if you look closely, and you can feel them with a fingertip. The purple vase print was done after changing to TR8x8 Z screws, and the Z wobble is gone. Of course you can still see/feel the print layers, but the wobble artifacts are entirely gone.
To check/fix things, I re-seated the hot-end,and extruder, checked the bearing mounts in the carriage and X gantry, checked the smooth rod mounts for the X and Z axis, using some small paper triangles to shim the rods to fit very tightly into the mounts. Something fixed that wobble somewhere.
MBot3D Printer
MakerBot clone Kit from Amazon
Added heated bed.
Leadscrew self-built printer (in progress)
Duet Wifi, Precision Piezo parts
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