EZ Struder Upgrade - Need help testing and refining.

[Jimustanguitar]

Hey guys!

I've been an EZ Struder user since it came out (I've been around long enough to remember Steve's original geared extruder) and it's been great. I've recently been interested in flexible filaments and other exotic materials, and have been finding the limitations of the extruder. Most recently with Bridge Nylon, I've been having the filament kink between the drive rollers and the filament "tube" through the extruder that meets the bowden fitting. You can see the air gap between these parts here, it's almost the width of the filament.

[img]http://i.imgur.com/lcUIprr.jpg[/img]

I also ran a print that required me to switch to a second spool of filament mid-print, and it was difficult for me to line up the new filament without any sort of guide to aim the new filament precisely... So, I started designing my own on Monday!

For starters, the majority of the credit still goes to SeeMeCNC. My design was drawn from their published EZ Struder stl files (which was actually somewhat difficult because of the injection molding draft angle in the files). I've added a tighter filament path, an inlet guide, and combined the base plate with the "output" plate that holds the bowden fitting.

[img]http://i.imgur.com/Osv8B2B.jpg[/img]
[img]http://i.imgur.com/fUByU4M.png?1[/img]

I designed it to reuse the existing tension spring and lever, and also to fit the original cover, etc. It prints in 2 pieces because that's how I overcame the protruding round on the face of the stepper motor without having to print an extreme overhang, and it's also a handy way to capture the bowden fitting without additional parts and hardware. I've also changed one of the screw holes so that it uses the stock length screw, it also gives you a handy thumb notch to operate the lever with (newer than most of the pictures in this thread).

[img]http://i.imgur.com/Z5pWkHd.jpg[/img]
[img]http://i.imgur.com/iijA9Rh.jpg[/img]
[img]http://i.imgur.com/nhjjL9l.jpg[/img]

I'll post the file on Thingiverse and Repables shortly and post the link here for you to try. Does anyone here have flexible or exotic filaments that they are interested in trying with it? I don't consider the design 100% finished yet, so I'm looking for community input on what else to tweak. I'm also hanging my extruder with a Trick Laser Fly-N-Strude kit, so it would be nice if someone could confirm whether or not this design mounts the same way as the original.

I'm also looking for a better way to print the filament path, because it's tough to print the filament passage without having it sag into an oval... Perhaps a future revision will have enough meat to drill out the passage or to install a PTFE liner. Thoughts on that are welcome as well.

Links coming soon, thanks!

[Jimustanguitar]

http://www.thingiverse.com/thing:1142707

http://repables.com/r/697

[duvdev]

OK that looks good.
I will try to print it and give it a test.
I have TPU,ninjaflex, bridge, soft PLA and some more that I want to test.

one more thing, I also got the flystrude kit ( It isn't assembled yet ) do you see any proof that it works better when the extruder "fly" on the top of the hot end? how fast do you print with it? do you have to go slower?

thanks

[bot]

Very excellent. That is exactly how I always pictured an (even more improved than already) ezstruder! I'll have to print this out and give it a shot.

[ccavanaugh]

Very Nice!

I worked up an extruder to better deal with a soft PETG and the result was fully trapping the filament before and after the drive gear much the same way you have.

You might consider a version that takes the original style E3D bowden adapter that allows you to feed the tube all the way to the drive wheel. It would require drilling and modifying the original aluminum piece like others have done before.

[Jimustanguitar]

Very Nice!

I worked up an extruder to better deal with a soft PETG and the result was fully trapping the filament before and after the drive gear much the same way you have.

You might consider a version that takes the original style E3D bowden adapter that allows you to feed the tube all the way to the drive wheel. It would require drilling and modifying the original aluminum piece like others have done before.

I've got one of the E3D adapters that lets you feed the filament through it, that's the plan. That's what I've been using on my current setup with the original EZ Struder, but I figured that the newer design would be helpful to more people out of the gate if it fit the stock SeeMe adapter first. A revision for the E3D part is the very next thing on my list. I'm also planning to make one that uses the HobGoblin drive gear.

[ccavanaugh]

Sounds great! I will have to pick up a geared stepper and give it a shot on for my next build.

Thanks!

[Jimustanguitar]

Yeah, I've been scheming about a geared stepper too... Too many projects, not enough time

[mhackney]

Jim, did you know the E3D groove mount adapter is a drop in replacement for the aluminum piece on the ezStruder? It is a little shorter than the stock part but 2 4mmID washers take that up easily. The advantage is you can then run the 4mm OD PTFE Bowden tube right up to the drive gear. I had modified the first 5 ezStruder adapters to take the E3D PTC fittings ccavanaugh mentioned but the last 4 I've simply used this part. Low profile and works great too.

[Jimustanguitar]

Jim, did you know the E3D groove mount adapter is a drop in replacement for the aluminum piece on the ezStruder? It is a little shorter than the stock part but 2 4mmID washers take that up easily. The advantage is you can then run the 4mm OD PTFE Bowden tube right up to the drive gear. I had modified the first 5 ezStruder adapters to take the E3D PTC fittings ccavanaugh mentioned but the last 4 I've simply used this part. Low profile and works great too.

Yep, I've been through that before. http://forum.seemecnc.com/viewtopic.php?f=35&t=7011&

I'll tweak the dimension for the E3D part this weekend.

[Jimustanguitar]

New files uploaded that fit the E3D bowden adapter.

Running a Bridge print right now to test for jams.

[nitewatchman]

Jim,

I printed and installed your modificated parts about a week or 10 days ago and the Rostock has run about 12 to 14 hours a day since with NO problems with common filaments - PETG, HIPS, PLA and ABS. I will take a shot at TPU next week but expect flawless performance due to the shrouded filament path. I had modified the E-Zstruder last year to better handle TPE and TPU by adding the PTFE Tubing to close the path downstream of the hobbed gear and roller. This made the use of the flexs in the E-Zstruder work well but made loading the filament a little fussy. The enclosed filament path above and below the roller solved this problem quite well.

Only had one small problem. I had to scrape the pocket for the pressure bearing out a little bit bigger. The bearing would close on the walls of the pocket and the pressure applied to the filament while present was not enough. The only suggestion I would add would be to extend the entry port for the filament higher or add provision for a short piece of PTFE Tubing to make loading easier. The hole to received the filament is hidden behind the manual feed wheel and a little hard to see.

In short -- I LIKE IT!

gary

[bvandiepenbos]

Nice work Jim.

Another weak part of the ez-struder is the flimsy red plastic lever. It twists and flexes, I think it causes friction and pushes filament out of a straight path.
The lever needs beefed up. Possibly a larger bearing also.

[mhackney]

+1 on the lever. This is where my issues are using the ezStruder with the Cyclops dual hot end. Also, the idler bearing has no groove to keep the filament in place (nor does the large cog that I use on the 8mm shaft geared stepper) so the filament can "float". I've actually observed this in operation.

[Jimustanguitar]

Thanks for the feedback, all.

The only suggestion I would add would be to extend the entry port for the filament higher or add provision for a short piece of PTFE Tubing to make loading easier. The hole to received the filament is hidden behind the manual feed wheel and a little hard to see.

I haven't decided if I'll try something like this http://www.thingiverse.com/thing:1172031 , or if I like the PTFE tubing idea better. I think I'm leaning towards lining the whole thing with PTFE tubing, actually. In that case, I think I'd just leave it hanging out the top an extra inch or so.

Another weak part of the ez-struder is the flimsy red plastic lever. It twists and flexes, I think it causes friction and pushes filament out of a straight path.
The lever needs beefed up. Possibly a larger bearing also.

+1 on the lever. This is where my issues are using the ezStruder with the Cyclops dual hot end. Also, the idler bearing has no groove to keep the filament in place (nor does the large cog that I use on the 8mm shaft geared stepper) so the filament can "float". I've actually observed this in operation.

I agree. Problem #1 that I set out to solve was providing a tighter filament path, so it made sense and was more convenient to reuse as many of the original EZStruder parts as I could. The lever may be next on the chopping block though.

If I redo the lever, I haven't decided if I want to make a stronger version that's a direct replacement, or if I want it to be custom... I'm thinking about making it longer, actually. In my mind, the arc that the idler moves along should pass through the center of the drive shaft so that different gears or differences in filament diameter and softness or flexibility would still align without taking the angle of the filament path out of whack as far. I haven't sketched that idea yet, but I do know that the stock arm is a shorter radius than the distance between the pivot screw and the motor shaft.


Part of me has really been thinking about making it a 1.75 mm FlexEZStruder, and marrying the SeeMeCNC concept to the thumb screw tensioner that LulzBot uses... Gary's post the other day about the melt-in threaded inserts has the wheels spinning about that again. Too many ideas, too few printers to make the prototypes on

[626Pilot]

I printed out the E3D version, but I can't close it around the PTF connector. There isn't enough space.

Also, I'm running a geared stepper with an 8mm shaft, and this drive gear: http://www.tridprinting.com/Mechanical- ... Drive-Gear

It's nice because it has a larger outside diameter (12.5mm). That puts more tension on the spring, making it less likely to skip. I don't think it would fit this mod, but it would be nice if it would. The geared NEMA17 steppers from TriDPrinting have LOADS of torque and weigh about the same as a normal stepper, so they're a good choice, at least in my opinion - especially if you're running a Cyclops, which can exert a lot of backpressure.

[Jimustanguitar]

Which dimension doesn't quite fit? Is it the diameter, or the shoulders?

I'm starting to figure out that dimensions that work perfectly for me are not the same that work for other people. Every machine is obviously slightly different, but I'm starting to wonder if it's me and it's a little more than slight... I might have to revert back from my OpenDACT EEPROM settings (a few versions old, mind you) so that my XY scaling is in alignment with everyone else. Then I'll have to print my own parts again and see if they work.

[nitewatchman]

Still using mine and it is working quite well. Much easier to thread.

gary

[626Pilot]

Which dimension doesn't quite fit? Is it the diameter, or the shoulders?

I'm starting to figure out that dimensions that work perfectly for me are not the same that work for other people. Every machine is obviously slightly different, but I'm starting to wonder if it's me and it's a little more than slight... I might have to revert back from my OpenDACT EEPROM settings (a few versions old, mind you) so that my XY scaling is in alignment with everyone else. Then I'll have to print my own parts again and see if they work.

It's about 2.5mm too narrow to fit around the nut part, and there's no allowance for the threaded part. I'll probably wind up doing a "remix" and uploading to Thingiverse. I'll let you know if I do so.

Check and see whether your arms have any play. Pull them outward from the center of the carriage hinges, then the effector hinges. Do they have any give at all? (Not flexion of the arm, but the ball moving around in the socket.) I printed a case for my PanelDue and discovered that the dimensions were millimeters off spec. I put the two boards on my scanner and scanned them in, and the holes line up with the screw posts in my model perfectly, so I know the geometry in the STL is fine. I tore down my Trick Laser arms today and discovered significant slop in the joints. Installed the new 300mm rods and now there's no slop.

[Jimustanguitar]

Any chance that simply scaling by a percent or two makes things fit?

I guess it's back to calibration cubes for me :/

[bvandiepenbos]

@626Pilot, any play in the arm joints is cancelled out when lash straps are installed because the joint is spherical. Even new joints sometimes have play.
With lash straps removing all play so your print quality is not affected.

[bvandiepenbos]

@Jim, the aluminum threaded piece for PTC does not fit in mine either. Did you draw parts on size or did you design in some clearance?
Typically I draw things with .5 mm of clearance to end up with a good fit. Drawn in DSM I assume, would you share file so I can adjust?

[Jimustanguitar]

Source File:

https://drive.google.com/open?id=0Bxa2n ... DNQNEFVRjg


*Edit* I don't think that file has the E3D bowden piece, but it's easy enough to measure your own and add whatever tolerance you like.

[626Pilot]

I tried to import your extruder STL into SketchUp, but there were too many polys and it choked.

Any chance I could talk you into modding it for the E3D fittings?

[Jimustanguitar]

I tried to import your extruder STL into SketchUp, but there were too many polys and it choked.

Any chance I could talk you into modding it for the E3D fittings?

It already does fit the E3D, unless there's a scaling issue between us.
http://www.thingiverse.com/download:1800171
http://www.thingiverse.com/download:1800169