Ultimaker2 Feeder System - Improvements and Ideas

[r2d2 1]

i love your idea of transferring the energy to both wheels and then using the suspension system within the second wheel to accomodate pressure on the filmanet and also the changes in filament diameter,,, we only need to find a material that can withstand these changes in pressure over weekes and months... any ideas guys on the right material ??

Cool work Ralf !!

Lets keep up this pace.... :smile:

Ian :smile:

Hi Ian,

if i had a printer :eek: i would print the axis part and the outside of the big wheel with pla and the suspension part with flexible pla ... but until now i have no experiences with this material (having already 3 reels from ultimaker next to me.. one is flexible - and they are all waiting to melt :evil: ) :roll:

or i would print only the axis part with pla and the outer part complete in flexible pla to get a good friction with the filament..

But im really not sure if a printed gear set is tough enough...

Ralf

 

[ian 32]

for a final product no.... but for a test rig... yes.. i think so

 

[ian 32]

at the moment we are all focusing on using a nurled bolt to bite the filament and then a flat slippy metal wheel to apply pressure.

Is there a mechanical problem with also having the same knurled design on the pressure wheel as well ?

Ian :-)

 

[r2d2 1]

Exactly! thats the point!

 

[takei-naodar 0]

Hi Everybody!

As Ian said I am indeed trying to solve the big obvious problems in a quick way (read: without having to build a completely new tool for injection molding). However, after that I would like to work on a new improved design of the feeder mechanism, so all ideas are welcome!

In case anyone would like to take a closer look on the 3D models of the revised feeder housing, I’ve uploaded the STEP files to GitHub:

https://github.com/Ultimaker/Ultimaker2/blob/master/1258/1258-B2P-D.STEP

https://github.com/Ultimaker/Ultimaker2/blob/master/1259/1259-B2P-D.STEP

@Daniel:

• Metal grommet: I just ordered a bunch of those rings for testing purposes. Let me know how much you need of them and I’ll make sure that you’ll get them.
  
• Flexible filament: I really like the idea of a snap on part that can be used for printing with flexible filament. We discussed a similar idea with Ian. I will definitely keep it in mind as an upgrade.
  

@Das_Enginer:

Great that you would like to test the revised parts. Could you please send me a message or an email with your address? Then I’ll make sure that you will get a sample of the metal grommet.

@Takei Naodar:

Of course! You can download the STEP files from GitHub.

@gr5:

Thanks for sharing your ideas! As said I am at the moment trying to solve the obvious problems in a quick way, but I’ll definitely keep them in mind.

@Bertho:

• Embedding image: I also had some issues with pasting an image link in the post and got a message that it wasn’t allowed. In the end I included the image as an attachment to the post, which did work.
  
• Teflon Tube: The closer to the feeder wheel, the better I guess. Do you think that the tube will still have a well-defined “end point” in your setup?
  

Thanks again for all your feedback!

-Bas

Ok i have to admit i feel lucky to have a 3930k in my pc otherwise the converting of the step files would have taken forever.

And i have to say..... i am fine with the general design but some details are a little bit off as far as i can see.

 

[woofy 12]

@r2d2

You will need the same sized gears, or you will be trying to drive each side of the filament at different speeds.

 

[r2d2 1]

@r2d2

You will need the same sized gears, or you will be trying to drive each side of the filament at different speeds.

No, thats not right! Indeed the bigger wheel will turn much slower but the way it makes on the outline will be exactly the same way the little wheel makes... important is only that the gears connecting exactly over the middle of the filament...

(this is hard for me to translate but i hope i get it clear...)

greets

 

[woofy 12]

Now I understand :smile:

That's a very clever design.

 

[ian 32]

I was just sitting outside for a minute with my Kitkat in my hand.. when I had a little idea.

I was thinking. on the UM1.. the reel is much closer to the feeder/extruder.... the filament is rolled up on the reel.. turns up and straight into the bottom of the feeder. the Knurled wheel and pressure wheel grab it and control it down the Bowden.

My queston is. we could do a very simple MOD.. where we have a nice simple reel holder than connects into the existing wholes and then comes out.. turns right and allows the reel to sit basically right beside the feeder and under it... so the flow of curled filament into the feeder is much more direct .. Plus if we were very sexy.. we could include a few metal washers/rollers.. so the movement friction of the reel would be greatly reduced.. like what ROBERT designed !

Todays KITKAT idea ;-)

Ian :-)

 

[Nicolinux 288]

Now this would be a very simple (and hopefully) effective mod. But this would only work for filament on spools. What about faberdashery filament for example?

 

[ian 32]

true ! i think its going to be tricky to do a solution that handles everything.. big and small reels and the loos reels from faberdashery.... but nothing is impossible !

 

[ian 32]

I took my feeder test rig off my printer. so I could do more testing seperatly and also let my normal UM2 just print stuff.

I selected a very cool Saint Patricks Day green beer jug to print last night. Watched it print for the first 5 minutes with the standard feeder.... click click click... stopped and cleaned the nozle just for safety... click click click... rose the nozzle temp to 240 and brought the speed down to 50... click click click....

Brought down the flow rate to 97 percent... slowed down to 40 !! and increaded the temp to 250 (hottest iv ever printed) clicking slowed down.

Came down this morning and found a finished green irish beer mug. that SAND could not be kept in... LOL

So little reality check for someone that would like a 3d printer that works.... there are 3 possible problems.

(1) feeder is........NOT GOOD

(2) feeder motor just is too weak.... or

(3) the Bowden is warping in the hotend from excessive heat transfer.

From these 3 points... Firstly im going to take off my feeder from my UM2.. and hand feed in the filament just to get a feeling of the resistance.

Secondly.. I have a old extra stepper motor from a UM1.. is that more powerful than the UM2 motor ? can I just swap that out on my UM2 ? same cable connections ?

Third thing.. the feeder.. if we stay with the existing knurled design.. we need a bigger diameter and maybe a better cut profile to pull into the material. At the moment this is hard for me on my limited income to accomplish.

Also I think if we do this and use some of the things learned here.. less contact friction. maybe a counter acting pressure wheel with driven power from the knurled wheel.

Of course what could be also possible is. this is a comination of all 3 things.. the feeder being uselss. the filament getting caught into bottom of the bowden and the motor tripping out every time there is pressure...

I want to focus more on the feeder part because that is the only part I can actually work on with the tools at hand.. the other parts... heres hoping...

Im just getting a little tired seeing a brand new UM2 print....... MOUSE HAIR !

Ian

 

[IRobertI 520]

The motors are different. The UM2 one is 400 steps/rev and the UM1 is 200 steps/rev. I also think I remember seeing someone posting that the new one is also stronger. Which would make sense as it's direct driving rather than getting the immense extra torque from the gear reduction of the UM1.

Putting a larger diameter knurled bolt would increase the amount of power needed to turn and since we're already living on the edge I don't know if it would be possible. With a gear reduction it would work of course.

Regarding the mount of the spool. I've toyed with the idea of moving it to the side of the machine instead. That way the natural curve of the filament would follow that of the bowden. The problem is that the new feeder sits so close to the machine that there would be a pretty bad bend at the corner of the machine. I haven't actually tried it though.

 

[foehnsturm 969]

I share your opinion about the feeder positioning. I've a sneaking suspicion that the position was chosen just because the motor fits so nicely beneath the axis stepper.

And as I posted today in the "Can your UM2 achieve ..." thread:

 

If I would own a UM2 and think about changing the extrusion stepper motor and the feeder design I'd go for a NEMA 23. In the reprap community it seems to be common sense that a direct driven 3 mm bowden extruder pushes even a high-torque NEMA 17 to its limits. It's a deadlock: limited motor torque asks for a knurled wheel as small as possible but its minimum size is limited due to the increasing risk of slipping and grinding.

 

[DidierKlein 729]

What about simply putting the spool underneath the desk where your UM2 sits? Having the filament going straight in the feeder?

 

[jay136 0]

I have my Ultimaker 2 on a small nightstand. I mounted the spool underneath the stand and the U2 on the very back edge of the stand. I printed a very smooth guide where the filament comes out of the back of the stand. It goes 13 inches straight up and into the feeder. For me it solved my under extrusion problem. My idea was to allow all the stresses that are rolled into the material when it is made to be relieved. I tried with an old roll of PLA that only had about 1 layer of wrap left on it(lots of stress)and it worked great. It also it may be just the fact that by going straight up I have reduced the friction. Was going to try running the filament over several rollers to see if it stress relieved the material and helped, but this works as is. While this does not help with the current location of the spool, just thought I would share.

[takei-naodar 0]

Regarding the mount of the spool. I've toyed with the idea of moving it to the side of the machine instead. That way the natural curve of the filament would follow that of the bowden. The problem is that the new feeder sits so close to the machine that there would be a pretty bad bend at the corner of the machine. I haven't actually tried it though.

 

Me neither..... for one reason....when you would print in the backside of the printplatform you still would have a very hign angle of 70-80° which makes no big difference to the actual design.. only that you changed left and right with back and front.

And yes i know my spoolholder design leaves wished open. On my current list of things to do on it are:

-Add ballbearings for the spools (less friction)

-move feederholder to the middle of the spoolholder and tilt the feeder by 60 degrees (allows for a more compact and less material intensive design, also less stress on the bowden tube)

-merge it with the adapter ( more sturdy design)

-fanholder

Sadly i dont have that much time on my hand currently which makes progression rates on my projects a little bit slow.

So if you want to take it on i and probably everyone would be very much oblidged

 

[takei-naodar 0]

Due to lucky circumstances i had unexpectedly some time on my hands and got to redesign my spoolholder.

I packed all the extras in it mentioned in my previous post.

 

-Add ballbearings for the spools (less friction)

-move feederholder to the middle of the spoolholder and tilt the feeder by 60 degrees (allows for a more compact and less material intensive design, also less stress on the bowden tube)

-merge it with the adapter ( more sturdy design)

-fanholder

Although the feeder holder did not make it to the middle and was just tilted by 45°.

The ballbearings to be used are 6808 61808 40x52x7 mm ones.

So i would like you guys to have a look at it and say what you think about it.

Download of the whole thing: https://dl.dropboxusercontent.com/u/90634021/Spoolholder.zip

And fo the ones that don't want to download it a nice litte pic.

 

[Nicolinux 288]

There's something wrong with the .zip. On my mac it produces a file with .cpgz.

 

[takei-naodar 0]

try to download again recoded it in deflate instead of bzip2

 

[Nicolinux 288]

Works now.

 

[ian 32]

morning guys :-)

I think some one posted this answer already here on this tread but for the love of me i cant find it.

George said that I can up the amps of the feeder stepper motor by entering this

M907 E500 - sets extruder current to 500ma. Default is 1250ma. Max is 2000ma.

My question is.. Do I create a normal gcode using cura from my model Then open it in TEXT editor and then just add the code M907 E500.

Can some one tell me exactly where I place this code ?

Thank you.

Ian :-)

 

[IRobertI 520]

Just place it at the top of the file. It just so happens that the first four lines of the file will be comments and then there's a convenient blank line to put it in. Saves you one button click

Also, if you set it to 500 you're going to have a bad time, the motor will be very weak at that setting. Since I started using 1500mA I've had zero skipping problems. I also use my new feeder but I'm not convinced that plays as big a role as the increase in current. The different spring pressure could play a part I guess as some people have reported grinding at higher currents with the stock feeder.

 

[ian 32]

Thank you Robert ! :-)

Ill give that a try tonight.

Ian :-)

 

[ian 32]

FILES ADDED TONIGHT:

Solidworks STEPFILES rig testing for UM2 feeder

I think there is still a wide spectrum of very interesting possabilities about how we can handle plastic filement and how it is being fed into a 3D printer.

This is a simple accurate test rig for 3d modelling for the back openings of the back panel of an ultimaker2 3d printer.

This is useful for me and maybe will help others get deeper into their own designs.

Ian :-)

https://www.youmagine.com/designs/solidworks-stepfiles-rig-testing-for-um2-feeder#!design-embed