V3b, V6, PET+ Questions

[johnross808]

Aloha everyone, just a few questions.
To print pet+ can I use the v3b hotend or will I need all metal?

I'm having trouble printing the v6 hot end bracket with ABS, it warps too much. Can it be printed in PET+ and will pet+ be a temperature resistant as abs?

Also should I be scaling the hotend bracket to compensate for the 1 to 2% abs shrinkage?

Mahalo, John

[jimc]

john, yes you can print pet+ no problem with the v3b. it requires about the same temps as abs. 245-255 is good for pet+. pet+ is almost as temp resistant as abs so you will be fine making printer parts with it. actually i think tim printed his filament drive with it. as for the scaling, it really depends on how the person modeled the part. usually scaling is not necessary but if there are tight tolerance parts then maybe BUT for printer parts, they are usually designed by someone to be printed so i would take a guess and say no. what drive unit are you trying to print? thingiverse link?

[johnross808]

Aloha Jim, Thanks for the answers.
I guess ill get printing with the pet+!
I'm trying to print http://www.thingiverse.com/thing:344950/#files
Every time I print the drive object the item warps where the dovetails connect. With ABS it takes about 100 pounds of pressure to get the hot end in and can only be removed by a dremel

Do you have a pet+ S3D profile handy?
Mahalo, john

[jimc]

hey john, the reason i asked about the model is because the one you are printing is mine . i have printed a bunch of these and usually do it at 80% infill. abs is always a pain. it can be tough but to do it, print it on kapton with abs slurry on it. you wont have to worry about it though with the pet+. you dont need to adjust the scaling with this model but you will need to follow the sanding instructions i put on thingiverse. the parts are designed to be printed tight so when you sand them smooth they will be in spec and slide on and off nice and smooth. i do have a pet+ profile handy but its for the e3d. are you printing with that yet or still the v3b?

[johnross808]

haha that's awesome, great design!
The shrink is so bad the filament doesn't even fit in the top hole with abs.
I bought some files for the dovetails and holes. But even with sanding the abs doesn't seem to fit right.
It may be my climate, its usually pretty humid.

I'm still printing with the v3b until I can print out your parts.
Mahalo, john

[jimc]

yeah it shouldnt be that tight. brand of abs can have alot to do with it also. abs all shrinks but i have had some brands shrink more than others. tuning of the machine can do it too. try turning down the extrusion multiplier a bit. you could be over extruding a little. drilling out the filament path when its all done is always a great idea. it makes everything nice, smooth and perfectly round. horizontal holes are never perfectly round when 3d printed. its not necessary but a nice machined hole never hurts. the drive is rsilver's. i only added the dovetails. alot of the m2 crowd runs his drive. its really nice.

[johnross808]

I've been using sainsmart silver filament but I do have some hatch box orange abs I can try. I'm not sure about the quality of each brand. Also I've been printing at 100 infill. 80 probably makes a big difference.
Do you think a raft would help with that piece?
Ill also check extruder multiplier.
Thanks for all the great advice!

[jimc]

no raft. use a brim though. that will always help. not sure if you are using s3d or not but i usually set it to 2-3 layers and 12 or so outlines. if i had to guess i would say your multiplier is too high or your filament measurement is off. the abs brand may or may not have any significant difference in the warping. do 80% instead of 100.

[Tim]

I'm late to the game here. But I want to comment that I made that V6 extruder mount in gray PET+ from MadeSolid, and it came out perfectly and worked like a charm. The main problem was that MakerGear introduced the dual extruder for beta testing just days after I printed it, so it got extremely limited use and is now mainly collecting dust! The dovetail did require a bit of sanding down until I could get the cover to fit over it with some hope of getting it back off again. I printed without a raft but with plenty of support, and printed at around 70% fill (can't remember the exact value). The rounded edges on the bottom do tend to cause the edges to warp upward a bit, but my print recovered after a few layers. The support is critical for PET+, which (for me, at least) is a complete disaster on overhangs. It does not bridge well across open air like PLA does.

[johnross808]

Thanks for the advice Tim.
I did some testing last night with makersolid pet+
I was able to get the first layer down perfect but on additional layers it started globbing up.
Initially I thought this was a extrusion multiplier problem but ended up finding the filament stopped feeding and the globs were just from sporadic filament coming out of the tip.
I also had problems loading the filament until I loosened the tension screw all the way out.
I had the filament stop flowing 3 times. So im not sure what's going on but will take a closer look tonight.
Do you guys use extra tension with the pet+ or same as abs/pla?
Sorry for all my dumb questions. I've only had this baby for a month.

My best result so far with the pet+ was a 1 cm cube. That was with the abs profile(s3d) with the temp changed to 250.
Mahalo, John