Jam Issues need V4 Extruder STL file

[jimc]

Try lowering your print temp a little. Your probably printing on the hot side which makes petg bond like crazy. This is a good thing but not with support or bridging. With esun and support i drop to 235. Everything still bonds but not like at 250. It bridges much better and you can actually remove the support. A 2mm bit is the correct size and a must to run down the filament bore. It just makes everything perfectly smooth and makes the hole perfect dia for the filament. Also scale up the part 0.4% in the x and y to compensate for shrinking and to make it stay in spec. The only difference i noticed with the drives on github is they are the older ones without the support hole for the teflon tube. Many of the v4 models on the github site are out of date but should still work. They should update those though. Its been awhile last i checked a couple months ago.

[Tim]

A 2mm bit is the correct size and a must to run down the filament bore.

Hmm, I looked back and realized I accidentally wrote that I bored mine out with 3mm diameter wire---it should have read 2mm (now edited).

Also scale up the part 0.4% in the x and y to compensate for shrinking and to make it stay in spec.

Question though; are the STL dimensions exact, or have they been scaled up by even more than 0.4% already to account for ABS shrinkage, which is what MakerGear prints them in?

The only difference i noticed with the drives on github is they are the older ones without the support hole for the teflon tube

I don't think MakerGear has any official drive models with a tube guide, do they? I was previously using the ones for the dual extruder that were redesigned by dryeti (viewtopic.php?f=13&t=1706). Those work very well, but on the dual extruder setup, the left motor is higher than the standard single v4, and the right extruder is lower (plus flipped relative to the left extruder), so neither model is correct for the single v4. Although I don't use Rhino or any of the fancy design tools, I've had some success importing the drive designs into openSCAD and splicing extra geometry onto them, so I'll make a new design with a guide tube and other useful features next week some time. I have a couple other designs further up the queue, though. But if anybody has a v4 single drive design with a tube guide, please post a link.

[jimc]

Tim, when i got the last printer which was a v4 dual, the drives had holes for the filent tubes. The spares i got from github did not. The githubs should still fit i think as they should have been correct at one point in time. Not sure on the scale thing. Abs is usually 0.8-1.2% depending on brand. Esun petg is 0.4%. Not sure if the models have already been done. Really we are only talking a few thousandths in the end so prob doesnt make a difference either way. He was having an issue so i figured i would mention it even though it prob wont be enough to correct any kind of alignment issue. His alignment problem would prob be in the z axis anyway which you never see any shrinkage on.

[wmgeorge]

Well right now its printing Jules file, she must have the print speed set up higher than I normally use. I set the Extruder temp at 245 C and Bed at 90 C because my back porch or shop is normally set at 65 DegF and with the PEI bed my actual measured with IR temp runs 10 under the set point. This is eSun PETG black,

My main issue with the github file is its loose on the motor mount indexing ring by a couple thousand inch, (and maybe the mount holes too) not a big deal but it requires the the exit hole to be lined up perfect with the in side of the V4 nozzle. I got tried of screwing with it and went back to the factory OEM part, you put it on tighten the bolts and its good to go?

Tim I had bored the holes out to a #49 drill size which I recall from memory is about 1.86 mm, I will find a drill that is 2 mm and use that instead.

Right now since it was a short run its printing from USB and I don't know where the cat is located. It loves to jump on computers and has no problem just walking across the keyboard!!

[wmgeorge]

Well Using Jules file I have it now running and printing. Both printed parts, mine and hers were oversized in fitting over the stepper motor gearbox mounting machined (22 mm) ring by ,25 to .45 mm. The resulting print from Jules file looked a lot nicer than the one I did yesterday. The other factor was Tim stated the filament guide holes should be 2 mm. I had the right size drill bit in stock and drilled them out. Mine was only .186 yesterday so the 2 mm gave it more clearance especially needed after the filament drive gear.

Thanks for the help, now back to the projects started 2 days ago.

[Jules]

Well Using Jules file I have it now running and printing. Both printed parts, mine and hers were oversized in fitting over the stepper motor gearbox mounting machined (22 mm) ring by ,25 to .45 mm. The resulting print from Jules file looked a lot nicer than the one I did yesterday. The other factor was Tim stated the filament guide holes should be 2 mm. I had the right size drill bit in stock and drilled them out. Mine was only .186 yesterday so the 2 mm gave it more clearance especially needed after the filament drive gear.

Thanks for the help, now back to the projects started 2 days ago.

I wonder if they don't already have some shrinkage for ABS factored into their files? PETG wouldn't shrink as much. (I don't remember noticing that the fit was particularly loose when i printed it in PETG, but it would make sense.)

[PcS]

All of mine in print are a little loose. It is really not a big deal to take a few seconds and eyeball the drive outlet twist clockwise or counter clockwise and tighten down when centered. I have not had one issue with feeding in doing so. I also drill every drive out as they need it.

[wmgeorge]

All I know is the OEM one is almost a snap on fit, Jules file was close to OEM but still loose but it worked. I did have to do some eye ball alignment, but the OEM one.... just slap it on and go. That is why I am wondering if there is a revised file?

[Jules]

All I know is the OEM one is almost a snap on fit, Jules file was close to OEM but still loose but it worked. I did have to do some eye ball alignment, but the OEM one.... just slap it on and go. That is why I am wondering if there is a revised file?

I'll bet the ABS they print with just shrinks more than PETG. Maybe if you printed one out of ABS it would fit the same as theirs.