Modding the Lulzbot Flexystruder for the robo3d

Lol just found another thing I have to fix. Lulzbot must use M5 mountingbolts, the nut recesses are way to big for the robo's M4's

Fixing that now My pile of fails is getting quite large now hahaha.

 

Fail Pile Growing LOL.. technically the last couple are not fails..just not quite right.. like the last 2 work mostly but the nut recesses are too big. Which I overlooked this entire time till now.

 

Latest progress:

Got it mostly working with PTFE tube in there, my major hurdle left is only the fact that my stock robo3d hobbed bolt is so uneven. Its tight/loose tight/loose as I spin it. Hopefully the hobb goblin gets here soon!

Now because the E3DV6 has PTFE that goes in it pretty far, and you can't release it from the little blackholder unless you can reach it.. I ended up cutting the tube as straight as I could part way through so that I can drop the hotend without dismantling the entire thing. This may end up being a bad idea depending on how much space ended up inside. Another option may just be to remove the little black PTFE holder on the top of the hotend, its probably not going to be needed? I want to be able to drop my hotend without dismantling the entire thing.

I mocked my extruder and hotend up and ran ninjaflex and pla through by hand, but the hobbed bolt uneveness is a problem I can't fix at this point.

Cut so that the lower portion always stays in the E3DV6, top always stays in the extruder.








Ran filiment through by hand and its working as long as im on the "tight" side of my hobbed bolt its perfect.



Even if I get this working I don't think its going to be a one size fits all .STL file that others can use..the tolerances are sooo finiky.. I might look into thingivers's modifier deal.

 

IT EXTRUDES! ( even with my poor uneven stock hobbed bolt which is making things really difficult, one side of it really digs in leaving major marks in the filament, the other side hardly touches the filament ) My Hobb goblin bolt will be here friday and I will finalize this deal and start printing with it then.

I haven't got to print anything because I busted my wire chain mount reinstalling everything.. going to print a new wire chain mount on my other printer.

I so far have just ran Esun Cleaning filament through it and ninjaflex, no problem but I could kinda hear and see when the hobbed bolt gets to its low spot..the filament doesn't come out even then. Didn't notice it with the ninja flex, that seemed fine.

FYI, the stock motor mount screws are a bit too short, I found some M3x10's in my toolbox that seem perfect. ( Additionally you will need longer M4's to mount the extruder to the carriage .. Mine are M4x25's I think..its all the hardware store had I think M4x22 would be perfect..for an E3DV6.



Also, I ended up using only 2 of the 3 original bearings otherwise my main gear was too far away from the motor gear. I used the stock small washer on the inside followed a stock bearing followed by two random M8 washers from the hardware store and then the main gear. Its not tighend down very tight because this is probably not the best setup. I need some propper washers.



Here she is installed




Poor quality image of ninja flex pushing out the remaining cleaning filament


Wire chain mount broke so I can't really print just yet


Final tally is I think 13 attempts LOL...and probably a few more once my Hobb Goblin bolt gets here but I have the process dialed down to modify them now lol


Here is a video of it extruding ninjaflex. ( Something my robo3d has never been able to do before - well it sort of could with a PTFE tube that was cut but not reliably..unsure how reliable this setup is but i'm digging it so far)

 

Forget sleep, I'm staying up to do a test print. crossing my fingers! haha

Duct taped and tied my wire chain up with a peice of esun eflex lol

 

Most I have ever extruded of ninja flex out of the robo..but its definitely slipping. 20mm/s print speed.. I'll try again friday when I get a better hobbed bolt.

Fail. some of it looked ok but i can actually hear it slip...at least it doesn't wad itself up ever like with the stock extruder...its just a slipping problem now I think.

 

I did pick a number, that was just my first try. I'm not going to try it again until i get a new hobbed bolt though. I'm just fighting a loosing battle with the really uneven hobbed bolt.

 

Well crap, I got the Hobb goblin bolt today but it appears that my bearings wont fit over it.

Hobb gobblin is correct I measured it at 7.98-7.99 everywhere these robo3d bearings are too small.

The robo3d bearings have some oddball 7.94mm inner diameter they say 608Z on them so they should be 8mm but they are too small, probably cheap

I found more 608 bearings, none of them fit over this hobbgoblin bolt. what gives. I could probably press them on with a press but they would never come off and wouldnt be adjustable

EDIT: Solved my bearing problem. I stuck the hobbgoblin in my drill. wrapped some 200grit sandpaper around it spun it a bit, then 100grit, then 600.. polished the shaft up bearings slide right on now.

 

Got it installed, hand feed test seems perfect off the printer it feeds it and its tight! at all times with ninja flex. PLA was almost too tight i had to press pretty hard while feeding to get it started, but then it was fine, and the filament came out pretty gnarled up.. maybe thats a good thing. If not i'll reprint again with another .2mm offset of space.

Currently the printer is heating up to try a ninja flex print.

EDIT: Fail...sorta

Good news is it extruded consistently with no issues/pauses/stoppages (thats really good news actually). bad news is lots of gaps between lines. this was with 1.0 ext multiplier in simplify3D. What do other people use? on my makerbot rep2 0.9 ( the default ) works fine and prints at 50mm/s no problem. Im gonna bump it up to 1.2 and try..for shits and gigs.

 

Another issue i have noticed is my ninja flex spool tends to really stick to itself..making it really hard for the extruder to unwind it. I kinda have to unwind a bunch and rewwind it so its loose.

 

All default, what should those all be? I have never had to mess with any of that before.

Some screenshots of my settings. Didn't show the skirt, but i have a 2 or 3 perimiter skirt at 8mm.. it seems to take about 1 perimiter before it starts fully extruding propperly.

 

So im printing now with the 1.2 extrusion multiplier and things are looking better...not perfect there is gaps between perimeters and fill. and some gaps between the lines on the second layer. But better than before. It feels strange to mess with Extrusion multiplier.. I thought that was a last resort kinda thing.

Edit: side note its extruding consistently with my modded flexystruder and hobbgoblin bolt so that is a huge plus.

EDIT 2: just read the posts from the link you sent me.. sounds like I should crank up the temp.. Im at 225 now.

 

It extruded and it printed..so thats better than its ever done before.

Hopefully just setting tweaks now.

 

Ok I'm calling this a success. The flexystruder works. My settings may still need tweaking but it feeds.

Here is print #2. I cranked up the overlap to 20% and the extrusion multiplier a bit more.

I'm super happy that it at least extrudes reliably.. no stoppages, no jams etc. The Hobb-Goblin bolt was for sure needed at least for me.
I will have to try printing with PLA tomorrow to see if it can still print that. I will post my source files this weekend.





i was pretty conservative with my Z offset, because stuff likes to get perma glued to my zebra skin



was only able to get a few threads on the locknut for the hobbgoblin but it should hold. I possibly could flip the bolt around. I will try later this extruder is only 15% infill for testing so I'm gonna re-print with more infill this weekend.

 

Ok, I really like what I'm seeing in the latest posts and would love to give it a shot on mine before resorting to modifying the carriage to hold the Bondtech.