Neotko FatIRobertI Bondtech Adapter Feeder for UM2+ / UM3

[neotko 1,417]

Neotko FatIRobertI Bondtech Adapter Feeder for UM2+ / UM3

https://www.youmagine.com/designs/neotko-fatiroberti-bondtech-feeder-for-um2-um3

Basically I wanted to have dual @Bondtech drivegears on my UM3. But buying two full kits is around 300€, by doing this design I could use the 40€ drivegears Bondtech sells (40€ each ofc) and change my 2 feeders reusing the Geared Extruder system from the UM3.

Downside? To avoid the feeder from hitting the spool, you need to reverse the motors direction. Easiest way is by changing the First two color cables from 1234 to 2134. If you don't know how to do this you could use a different spool feeder so it doesn't hit the release arm. But that's up to you... Print Mirroed if that's your plan for a UM2+.

Use supports for anything 50degrees or more. Also use 50% Support Density, or the nut holes will print badly. Same goes for the feeder arm, and areas that do need support. I didn't design my supports just because I didn't saw it necessary. Used default S3D support settings with 50% support density and all worked perfectly and was very easy to remove them.

Feeder print settings use 2 perimeters and 20% infill should be more than ok. I use 24% because that's why I use.

The inside area between the part a-b should hold a ptfe liner from a bowden tube (maybe one that broke and you have for a rainy day?). If you can't do that, it might be problematic to feed the filament since is designed this way for many reasons.

Printable Shaft Adapter

The Printable-Shaft-Adapter MUST be printed at 80-90 infill, rotated 45 Degrees and without supports of any kind. Also 2-3 perimeters and I used -0.03 horizontal expansion to print this part (not the feeder) and also used 0.15 layer height, 0.2 could work, but this part must be printed slow and with precision. That's why I used Extrudr GreenTec (high temp pla that goes up to 110C without a issue). I don't think this part would work with ABS (because the flexibility) or normal PLA (because the heat deformation), but you are free to test anything you like!

This part uses a m3 30mm inside, you will notice that the screw passes soft until the end, that part need's to be screw in, don't force it, is made to fit perfectly. If something fails, your filament size might not be correct, check it with a caliper.

Also CHECK that the bondtech gears passes without too much friction, because you will need to readjust the position after assembling all to align the feeder line so all works perfectly. Is a basic calibration process. Something like this:

Inserting a filament after all is assembled will show you clearly if all is perfectly aligned. If not, release the bondtech gear and align it and rescrew it. The same way you would do on any feeder...

@Gudo made me a few small shaft CNC. Without his help I might not have finished this feeder so fast. Also I got the idea of using a printed shaft adapter by talking to him. So many thanks @Gudo !!!

To print the Feeder use 0.18 or less, but it doesn't need more resolution. 0.2 is possible but I don't like how the part where the filament passes looks. 0.18 was perfect on all the test prints while making this.

To print the second Core extruder mirror all the parts.

There are 3 Versions.

- 1.75mm using 6mm-4mm bowden

- 1.75mm using 4mm-2mm bowden

- 2.85mm using 6-3mm classic UM bowden

To use this feeder you need

- Bondtech Drive gears (the big ones, no the thin ones I used for the other FatIRobertI feeder.

- 4mm Shaft 22mm long (bondtech sells them too) is where the mirror gear spins.

- screws, nuts, screwdriver...

This Feeder could be really really fast adapted to use MK8, but would need a change on the IRobertI Arm to fit the UM2+/UM3 feeder bearing.

I did use a spring that Bondtech did sell before that isn't included now. If they don't sell it to you (asking never hurts) you can reuse the UM2+/um3 spring, but mind that you will need a M3 35-40mm to use it. Also the force of the spring is quite too much from what is necessary for bondtech gears, so.. mind the force.

Important about the Hands part.

You will need quite force to fit the 4mm shaft of the mirror gear. I used a Vice bench. Tested on 9 prototypes, it works, and works perfectly. BUT TRIPLE check that you align all before doing this, because it won't be any easy to unclamp it, and most of the time it needs so much force that the arms break (very easy to reprint part). Also, READ the photo, you need to put the feeder part near the thin part of the arms, it's on purpose and is really necessary. Why? Too tired to explain

Note

You will need to download the LATCH from the IRobertI original design

https://www.youmagine.com/designs/alternative-um2-feeder-version-two

Edited December 11, 2016 by Guest

[nerdwarrior 19]

Amazing design, as always, @neotko! Great writeup as well!

I saw this and it got me thinking: for people with the UMO+ or UMO that want to change to the big bondtech gears, it will probably be easy to print an adapter and use the rest of this design.

And nope, I haven't used up my 3 kg of filament yet, so I haven't upgraded by extruder to your design With this one out as well, I can't wait!

[neotko 1,417]

Umm....

Indeed it should work with the @meduza adapter https://www.youmagine.com/designs/um2-extrusion-upgrade-kit-mount-for-umo

And printing it mirror.

I suppose printing the um2+ gears should be possible too.

[nerdwarrior 19]

Good to hear! Will add this to my list of things to do!

[DeathMachine 23]

Yes! nice going to have to too doing that upgrade. also like the Meduza bracket.

[supermanny 2]

Really nice design neotko.  I've been looking at this for a while and thinking about doing this upgrade.  I'm wondering if printing flexibles is an easier with this setup?  Looks like filament path and feeder gears support the filament at all times.

[neotko 1,417]

Really nice design neotko.  I've been looking at this for a while and thinking about doing this upgrade.  I'm wondering if printing flexibles is an easier with this setup?  Looks like filament path and feeder gears support the filament at all times.

 

Thanks!

Well the filament path is better for flexibles, but I haven't tested it since I have this 2 extruders on the um3, and I think to print fast there is a waste of time for flexibles since IMO because the curvature of the bowden + the mm of open space of the um3 cores.

I use the other FatIRobertI on my umo+2 and I can print flexibles with a minor degree of retractions and 40-50mm/s without problems, and since the principle is the same it should work. Anyhow I would really install the feeder on a different position to avoid the weird curvature the bowden does as default.

Edited January 23, 2017 by Guest

[derbroti 4]

Nice one

You say "using 6-3mm classic UM bowden" - just to make sure: you designed it with the 1/4" (6.35mm) OD bowden in mind, right? not plain 6.00mm?

And would you be so kind to release the design file for "Um2plusbondtech Holder" - I would like to add clips/brackets (not sure how to call them correctly) to get the black cable nicely tucked away - because messing around with STL files is annoying.

thanks!

[neotko 1,417]

Nice one

You say "using 6-3mm classic UM bowden" - just to make sure: you designed it with the 1/4" (6.35mm) OD bowden in mind, right? not plain 6.00mm?

And would you be so kind to release the design file for "Um2plusbondtech Holder" - I would like to add clips/brackets (not sure how to call them correctly) to get the black cable nicely tucked away - because messing around with STL files is annoying.

thanks!

It should work I think. I can't release the files, many of the parts and measurements come from the @IRobertI feeder. So the step files ain't just mine to release

[derbroti 4]

It should work I think. I can't release the files, many of the parts and measurements come from the @IRobertI feeder. So the step files ain't just mine to release

As I said, I am interested in just one single file of the feeder, but I understand, so if @IRobertI gives his ok? (Will he get a notification when mentioned with @ ?) Worst case, I have to redo the measurements myself

[neotko 1,417]

But to add stuff you don't really need the step file? Send me the design you want to add and I'll give it ago. (Or just make a doodle of where you want to clip the cables)

In theory since I used the IRobertI measurements for the bowden, it should work with um2/um2+ standard bowdens.

Edited January 31, 2017 by Guest

[IRobertI 520]

Yes, he does get a notification It's OK with me. I really should put the steps up on the site. I'll see if I can remember to do that tomorrow.

[derbroti 4]

But to add stuff you don't really need the step file? Send me the design you want to add and I'll give it ago.

The problem is that I am currently "blessed" with onshape - which can not import STLs in a reasonable way.

Basically something like this - super simple clamping hooks: (probably with a steeper hook angle, and further apart or 3 instead of 2, but you get the idea )

onshape document

Thinking about it - maybe the other way around - so the opening is facing the printer wall - then the cable is definitively fixated...

In theory since I used the IRobertI measurements for the bowden, it should work with um2/um2+ standard bowdens.

Great :)my bondtech stuff should arrive soon, so I can try it out.

Yes,  he does get a notification :)It's OK with me. I really should put the steps up on the site. I'll see if I can remember to do that tomorrow.

Good to know and yay - thanks!

Edited February 1, 2017 by Guest

[IRobertI 520]

Good to know and yay - thanks!

 

Uploaded a zip with step-files. Hope it helps.

https://www.youmagine.com/designs/alternative-um2-feeder-version-two

[derbroti 4]

Uploaded a zip with step-files. Hope it helps.

 

Thanks!

@neotko As Robert gave his ok, can I kindly ask again for the file?

[neotko 1,417]

 

Uploaded a zip with step-files. Hope it helps.

 

Thanks!

@neotko As Robert gave his ok, can I kindly ask again for the file?

 

Sure you can ask

I'll pm to you the back parts so you mod it, but I'm very busy this weeks to upload a final step file. It has some small details that i'll like to improve before that.

[derbroti 4]

Sure you can ask

 

 

I'll pm to you the back parts so you mod it, but I'm very busy this weeks to upload a final step file. It has some small details that i'll like to improve before that.

 

Thanks No problem, take your time!

[neotko 1,417]

 

Sure you can ask

 

 

I'll pm to you the back parts so you mod it, but I'm very busy this weeks to upload a final step file. It has some small details that i'll like to improve before that.

 

Thanks :)No problem, take your time!

 

Uploaded that step file, is one of the parts that I would change, specially to cover the hole on um3 from the filament sensor cable. But I prefer to upload it now so I dont forget it! (much to do be do be do lately)

https://www.youmagine.com/documents/54666/download

[derbroti 4]

Thanks!

Haven't had time to print it yet, but soon will.

One question however: the Bondtech gear size is slightly different in diameter than my current UM2+ feeder knurled wheel - this should result in a slightly different E-step value right? I mean it will only be a minor difference but it is worth to recalibrate, right?

[neotko 1,417]

Thanks!

Haven't had time to print it yet, but soon will.

One question however: the Bondtech gear size is slightly different in diameter than my current UM2+ feeder knurled wheel - this should result in a slightly different E-step value right? I mean it will only be a minor difference but it is worth to recalibrate, right?

 

Oh indeed, is one of the things I forgot to post...

For Bondtech 8mm bore dia (the ones used for this mod)

- 1.75mm version might use something like 307.64 or 314.19 ( can't remember which one is the correct since I have the um3 off  for a month or so, will update when I turn it on)

- 2.85mm version MIGHT (can't be sure since I don't use it) 323.6 This is in theory should work, but is only based on my experience and because I had a bondtech step file that gudo made for me with all the measures. Anyhow it should be a good starting point to calibrate it.

Other way to do it...

Bondtech feeders that use that drivegears 2.85mm use 492.45 for their 1:5.18 planetary geared motor. So.. let's do some math

This shows that the ledscrew number is close to 32.4905

That shows a 10.342 effective dia umm

Ok if we change the motor to 11:36, like the one um2+/um3 uses it gives a...

322.33 esteps

I would try that number, it might be spot on, or totally wrong

Edited February 6, 2017 by Guest

[derbroti 4]

I would try that number, it might be spot on, or totally wrong

 

Haha, your math sounds promising - so, I will give it a try

Edited February 6, 2017 by Guest

[derbroti 4]

I finally managed to print your feeder @neotko

It is pretty nifty - I have just a few minor things - that hopefully are not related to my printer:

first: the nut holes for the screws that connect front and back are way too big for me.

second: the bearing "hole" is also too big: my bearings from the UM2+ feeder are not tightly in your feeder.

and, which is a bit more critical: The hands have too much room to rock up and down during retracts.

and lastly: for me (I use a quite short soft spring) the hands are "bend" to the outside when I tighten the spring even a little. -> The spring presses in the middle but the opposing force comes from one side of the hands: You know what I mean?

Pictures:

My clamps:

open:

closed:

the "rocking"

 

[neotko 1,417]

Indeed that's weird. It might be something to do with the material you used and mine, for example for me the nuts are a tight fit, not too tight but fit. Clearly I made the feeder so I could print it, made like 7 printed versions changing stuff until it worked. Maybe is just that your printer extrudes less than mine or mine extrudes more than yours.

I think cura has an option to expand the walls. I would try to reprit the nut with +0.10 expansion. And if works, reprint all.

[derbroti 4]

I think cura has an option to expand the walls. I would try to reprit the nut with +0.10 expansion. And if works, reprint all.

 

Interestingly: the channel for the PTFE tube is a tight and precise fit - that's why I ruled out my printer as the issue.

[neotko 1,417]

 

I think cura has an option to expand the walls. I would try to reprit the nut with +0.10 expansion. And if works, reprint all.

 

Interestingly: the channel for the PTFE tube is a tight and precise fit - that's why I ruled out my printer as the issue.

 

I will take a look but dunno. Maybe I can print a cube 10x10 and measure it so we can check the differences so you can use cura/s3d horizonta expansion options