SoliForum - 3D Printing Community — PLA extrusion

Re: PLA extrusion

2013-10-08T23:32:40Z

I would never turn down another gearbox, it would be nice to have all four units fully functional lol

Re: PLA extrusion

2013-10-08T22:20:44Z

Wow. Yeah that's not holding up, and is the performance I expected for printed gears in that application.

I can just send you another gearbox...

Re: PLA extrusion

2013-10-08T22:06:34Z

Tim... I wouldnt say they hold up exactly.... but then i havent gone up to 100% infill yet. at 30% a gear lasts 1-3 hours before giving out. at 50% 3-5. Think i need to see how long a copy of the originals would work, which means taking apart another motor to scan.

Re: PLA extrusion

2013-10-08T21:42:57Z

That's great feedback. I wanted to see the ABS gears you printed though - I am impressed they hold up! I understand you not wanting to post them though.

Re: PLA extrusion

2013-10-08T21:38:06Z

Got stuck working a double but had pictures of the gears on my phone, quick web upload and post until i get out of here. (being management sucks somedays)

Small gear stripped entirely.

large gear missing teeth, and the teeth from the small gear in the bottom of the gear casing.

another view of the large gear and small gear teeth

Tim Yes i prebake. the variance issue i have with pla is i am testing extrsusion straight down rather then off of a table or other surface, my non test unit is extruding between .04 and .06. The gear issue i think was caused by a combination of issues, 1. I was only running at 140 2. Not Thinking I used pla that i had baked the night before without re-baking it 3. I had this shaft locked to the motor with a gator grip.
Slippage was not going to happen so the teeth gave, honestly i would have expected the motor to burn out before the teeth giving especially with only having about 50 hours on this motor. I have a few different high torque motors that i ordered (including a few that match the ones shipped) intended for testing increasing speed after i was happy with the rest of the setup. Moore's law i suppose, What you dont plan for happens. Go figure.

Re: PLA extrusion

2013-10-08T17:21:34Z

True, but you're not using the same controller. I get the feeling your controller's 140 is like the Mypin/Sestos' 155-160.

To everyone else: 2n2r5's PLA 'struder has an early beta PID controller that kinda wasn't too great.

Re: PLA extrusion

2013-10-08T17:13:07Z

I am also using much lower temps 138-140C. At 160 the pla would be so running it would basically flow like water coming out of the nozzle.

Re: PLA extrusion

2013-10-08T17:09:34Z

digitydogs wrote:

I mistyped earlier my current pla variances are .1 not .01.

Are you drying the pellets? 2n2r5 is reporting +/-0.05mm on PLA without water cooling/PTFE nozzle/etc.

Re: PLA extrusion

2013-10-08T16:39:51Z

i will gladly upload some pictures after work (4pm est). Why anyone wants to see a picture of ptfe tubing rigged in is beyond me... anyone can do that just drill your hole out by 1/64 of an inch and only go in a 1/32 of an inch (but ill still share that as well). Pla doesn't seem to have much issue with sticking, but then i also lubed up the tube just to be safe and i run a small amount of lubricant through my machine with my pellets as well (have had zero noticeable difference extruding and printing this way with either abs or pla, better tolerances resulting from less drag and snag, though if you use too much or the wrong kind of lubricant it will mess the filaments up). ABS i haven't tried with a tube as i already have tolerances as low as i think possible without getting a better caliper and making unnecessary changes (.01-.02 is plenty good in my opinion) I mistyped earlier my current pla variances are .1 not .01. Water cooling i will not be uploading pictures of as it is rigged up and still a work in progress (im using an old car fuel pump and a horribly rapidly thrown together plexi box and fish tank tubing for crying out loud). Once i get it to work reliably and not look like something a kindergartner assembled ill be happy to share that as well. The new gears i made were done with the customizable gears on thingiverse, i wont upload pics of those either because ive only been using them for about 8 hours of extrusion and don't want to be responsible for anyone that doesn't read and research carefully and fries out their motor due to bad gear ratios trying to increase speeds. Again PLEASE unless you have alot of money to play with DONT try any of this yet unless your confident you know what your doing.

Re: PLA extrusion

2013-10-08T14:34:49Z

I'd also like to see a picture of the replacement ABS gears. This is the first report of gear failure in the new motors.

Re: PLA extrusion

2013-10-08T14:17:32Z

Also post a picture of the PTFE tube. I couldn't get that to work with ABS. Apparently ABS doesn't have much friction when liquid, and not much when solid, but is more sticky when soft and rubbery. Trying to guide it through a tube to protect it during the transition from rubbery to solid always resulted in jams, or extremely slow extrusion if it made it out the other end at all.

PLA has a much sharper transition between liquid and solid, so maybe that approach will work.

Re: PLA extrusion

2013-10-08T14:17:28Z

digitydogs wrote:

So I shredded the gears in the one extruder as I thought... Rather cheaply made gears in these motors.... Actually regeared it with abs gears, extrudes 75% faster do to the new gear ratio. Been playing with pla since.... My best results are at 165c. Using a PTFE tube inserted into the nozzle for size stability spooling and water cooling I am getting +-. 01 mm variances in pla.

Well I'd like to see the "PTFE tube inserted into the nozzle for size stability".

Ralph

Re: PLA extrusion

2013-10-08T13:34:17Z

Can you post a picture of your water cooling setup?

Re: PLA extrusion

2013-10-08T13:21:14Z

So I shredded the gears in the one extruder as I thought... Rather cheaply made gears in these motors.... Actually regeared it with abs gears, extrudes 75% faster do to the new gear ratio. Been playing with pla since.... My best results are at 165c. Using a PTFE tube inserted into the nozzle for size stability spooling and water cooling I am getting +-. 01 mm variances in pla.

Re: PLA extrusion

2013-09-29T13:09:12Z

I was running with way too much pressure testing different extrusion temps due to moisture. Didn't follow my own rule and used pellets I baked the night before.. Prolly just came off track/broke a gear inside the box, easy fix. Tim was correct about my unclear statement on extrusion. When using the filament the higher temps we print with remove most issues with moisture and isn't a concern. Its only when making filament its an issue. Jesse no one has per say mastered pla Yet we are all still looking for the best method. I'm about to begin some experiments involving pla 160 temps PTFE tubes and water. Once I get a stable reliable method down I'll post here.