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Ultimaker2 Feeder System - Improvements and Ideas


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Posted · Ultimaker2 Feeder System - Improvements and Ideas

16 outer, 8 inner, 5 thick.

I've mounted my newest iteration but I just remembered that since the idler wheel has switched location I'm effectively running in reverse. I don't suppose there's a quick fix for that? I don't feel like physically moving the pins of the connector and I've actually never compiled a custom version of the firmware.

If a custom firmware is the easiest fix I'd really appreciate if someone could compile and upload a hex for me that matches what is in the machine except for the direction of the extruder (don't want to introduce any other variables into the test).

 

Robert, if I can afford.

And if you install a set of gears ratio 1? It takes only two gears with the same radius and an equal number of teeth for the reverse driving direction.

 

First sprocket on the motor.

The second sprocket, which drives a shaft on the knurled pulley.

 

It is no question of changing Marlin, sprockets are charged with the reverse direction and the ratio of 1 can also stay on the same data. :cool:

 

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    the extrusion distance per step is probably different.

    Isn't this just a software setting somewhere? Something like extrusion distance per step?

     

    Yes. There's a ton of ways to do this - maybe the easiest is you can just add a gcode to do this.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    telophar

    My UM2 came with a plastic knob which there was no information about in the manual, but I just assumed it was to be used as a guide for the filament.

    2014 02 15 3154

    The feeding, at least for ABS, appears to work much better for me when the filament runs around this knob.

     

    I have also noticed a few things regarding the feeding mechanism.

    - When changing material, the stepper motor apparently is running at reduced current, since it skips steps when the filament hits the nozzle.

    - On my printer there appears to be a firmware bug, because I have to power cycle it after changing material for the "move material" option to work.

    - Using the move material option, the stepper motor is much more powerful than when changing material, which means it easily grinds down the filament if one is trying to feed to fast.

     

    I am curious to why the stepper motor apparently has much less torque when changing material (at the low speed in the change material cycle).

    When the filament hits the nozzle, it still extrudes with a much higher speed than for normal printing.

    Is there a setting somewhere in the firmware where the torque of the stepper motor could be reduced?

    I mean, when the stepper starts grinding the filament down, it is not feeding anyway, so limiting the torque a bit should not have a negative impact on the feeding i think?

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    I don't have a UM-2 but I've printed ABS, PLA, and nylon extensively for nearly 1-1/2 years with my UM. Here is what I've learned.

    1. ABS is more prone to jams and partial jams (slowdowns and under-extrusion) than PLA or nylon. You can expect ABS to under-extrude as a matter of course when running medium to high extrusion rates. Illuminarti has studied the problem extensively. The faster you extrude ABS, the more it under-extrudes. To some extent, I often compensate for this property in the slicer. If you learn how to use netfabb well (very time-consuming) it provides more flexibility for doing this than any other slicer. With netfabb's UM Engine, you can define many extrusion "types" and tweak the extrusion fudge factor up when extruding at high rates. It's also unfortunate that netfabb appears to be an unsupported commercial product nowadays and many bugs remain in the ap. Actually, the UM Engine has never been very well supported by netfabb GmbH.

    2. I was disappointed when I first saw the very clean and sleek-looking UM-2 filament feeder design. Support for manually feed (forcibly pushing up on the filament with one hand while turning the feeder "big wheel" with the other hand) can greatly reduce the likelihood of jams and also get that most important first layer off to a consistent high quality start. With ABS, I try to be around when the print completes to force feed filament before retracting the filament from the hot end and shutting down. If I'm not around, I use shutdown G-code to at least purge the head, reduce the temperature in stages (feed at ~10C steps) and retract the filament before it cools (sometimes--don't know whether this step helps or hurts). Immediately before every print, I manually force feed the filament to both "clear" and pressurize the hot end to normal operating pressure and temperature.

    3. I made a hobbing tool for my lathe and I have made a few conventional hobbed stud feeders in various tooth pitches. The best of them provide significantly more power than the standard UM "knurled" or "checkered" rev. 3 hobbed stud, but they are more prone to clogging than the original stud and they are difficult to clean when they do fill with plastic. Currently, I'm using the original rev. 3 stud, because it cleans up with a few quick swipes of a toothbrush and really never clogs to begin with. I simply slow down when/if it starts to slip too much and under-extrude.

    If I were still printing a lot of ABS, I'd probably upgrade the entire feeder mechanism, but I mostly print nylon these days, sacrificing a little print resolution for improved strength and chemical resistance, as compared to PLA or even ABS. At normal nylon extrusion rates, the filament feeder drive capabilities are not a factor. I build manufacturing tools and commercial parts with my printer. It supplements my company's small machine shop. I don't print garden gnomes.

    4. I've studied many filament feeder designs. Someday, I'll build a Rollerstruder:

    http://www.tridimake.com/2013/04/rollerstruder-filament-feeder-driver.html

    including its very large and aggressive hobbed bolt:

    http://www.tridimake.com/2013/03/which-hobbed-bolt-for-filament-feeder.html

    Counter-rotating, dual-drive feeders also have merit, but they are more complex to design and build.

    If I ever get a UM-2, I'll hang a UM-original feeder on the back or perhaps the Rollderstruder.

    Just my $0.02!

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    [...] If I'm not around, I use shutdown G-code to at least purge the head, reduce the temperature in stages (feed at ~10C steps) and retract the filament before it cools. [...]

    I'm interested in the way you set this up - could you please share/explain how you do this??

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    [...] If I'm not around, I use shutdown G-code to at least purge the head, reduce the temperature in stages (feed at ~10C steps) and retract the filament before it cools. [...]

    I'm interested in the way you set this up - could you please share/explain how you do this??

     

    calinb lists many good points above.

    I too like to avoid the heat creeping up the extruder after shut down. To avoid it I slowly feed some extra filament while the head normally cools off. That way cold filament is pushed in so the heat never creeps up and later creates a possible jam at start-up. The actual code is extremely simple:

    G1 F40 E75 (tweak it to fit your machine)

    Here is my complete end code:

    ;End GCode

    M104 S0 ;extruder heater off

    M140 S0 ;heated bed heater off (if you have it)

    G91 ;relative positioning

    G1 F300 E-5 ;retract the filament a bit

    G1 Z2.0 F?max_z_speed? ;move straight up

    G1 X-20.0 Y-20.0 F9000 ;move quickly off the print area

    G28 X0 Y0 ;home X/Y, so the head is out of the way

    G1 Z40.0 E5 ;lower the table to leave space for extrusion

    G1 F40 E75 ;extrude to cool off the head quickly

    M84 ;steppers off

    G90 ;absolute positioning

     

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    No good news, first print was a big fat fail. Things aren't lining up just right -> more friction + filament almost slipping out of the guide wheel -> even earlier under extrusion.

    That and my first print of my UBIS converted UM1 failing even worse than this (I don't even want to know how much time and money I've spent on that bloody thing...) means I'm out for now. I'm in a baaad mood.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Roh!

     

    You should never given up IRoberti!

     

    Look, I struggled 24 hours to create my own part. I even find a spring that was longer and slightly less strong. And it worked a while.

     

    Today my teflon HS .. The nozzle can also be ... And I wait! Better days will open before us.

     

    For against, I think my review system to put 2 screws instead of 4 ... , I have my own idea! As an easily removable wear part and on the portion of wire ... As a mechanical inversion of the position of the spring! In short .. Have to be patient until receipt of spare parts ..

     

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    Posted (edited) · Ultimaker2 Feeder System - Improvements and Ideas
    On my printer there appears to be a firmware bug, because I have to power cycle it after changing material for the "move material" option to work.

     

    Daid? Did you see this?

    I haven't noticed but I don't change filament very often. Do you have *firmware* version 14.02? It fixes some bugs like this.

     

    I am curious to why the stepper motor apparently has much less torque when changing material (at the low speed in the change material cycle).

    To reduce even further the chance that you will grind filament. You can change the driver current with a gcode. I posted it somewhere else. I think maybe in "extruder pull test" maybe. I need to rename that to "feeder pull test" which I might do now.

    Edited by chin
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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    I changed the name of this topic to mention "feeder" instead of "extruder". It was pointed out to me by 5 people in the last 5 days that the extruder consists of the feeder behind the UM and the head/nozzle. This topic seems mainly to be about the feeder.

     

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    Posted (edited) · Ultimaker2 Feeder System - Improvements and Ideas

    [...] If I'm not around, I use shutdown G-code to at least purge the head, reduce the temperature in stages (feed at ~10C steps) and retract the filament before it cools. [...]

    I'm interested in the way you set this up - could you please share/explain how you do this??

     

    Sure. From extensive destructive testing of my parts using a torque wrench to measure failure loads, I know my Ultimachine black ABS requires high nozzle temperatures to achieve good layer bonding strength. (I often print it at ~260C). The heat creep at shutdown can create problems for the next print run. Try something like this:

     

    G91   ;Set to relative modeG1 X2 Y2 Z0.2 E-5 F10800 ;Suck back 5 mm filament to minimize blob on the partG1 X0 Y0 Z4.8 F500 ;Keep moving awayG90   ;Set to absolute modeG1 X209.00 Y209.00 F5000.00 ;Move to prime zoneG92 E-5          ;push previous 5mm filament back into nozzleG1 E1 F500       ;Extrude 1 mm net for cool-downM109 S250        ;Cooldown--wait for 250 CG1 E2 F500       ;Extrude 1 mm moreM109 S240        ;Cooldown--wait for 240 CG1 E3 F500       ;Extrude 1 mm moreM109 S230        ;Cooldown--wait for 230 CG1 E4 F500       ;Extrude 1 mm moreM104 S0            ;nozzle cooldownM84                   ;disable motors 

     

    Edited by chin
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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Sounds like you have addressed this too, Bertho.

    I think avoiding the heat creep is important at shutdown. I'm not sure that retracting the filament after the cool down period helps at all, though I mentioned it as an option. (My code, above, doesn't retract). I think that retracting the filament might actually cause problems, on rare occasions, because small fingers or bridges of filament can be formed at the end of the Bowden tube/Teflon tube, which might fold over and jam the next time the filament is driven into the hot end. I just don't know, but I know that avoiding heat creep on shutdown is a good thing.

     

    calinb lists many good points above.

    I too like to avoid the heat creeping up the extruder after shut down. To avoid it I slowly feed some extra filament while the head normally cools off. That way cold filament is pushed in so the heat never creeps up and later creates a possible jam at start-up.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    No good news, first print was a big fat fail. Things aren't lining up just right -> more friction + filament almost slipping out of the guide wheel -> even earlier under extrusion.

    That and my first print of my UBIS converted UM1 failing even worse than this (I don't even want to know how much time and money I've spent on that bloody thing...) means I'm out for now. I'm in a baaad mood.

     

    Hi Robert !! :-)

    First piece of info !! I chatted with Harma and she is going to send you tomorrow an extruder set so you dont have to take your ultimaker2 apart all the time. I got one as well and its a fantastic help to have things printing and at the same time, a set in your hands to check and measure...

    Also can I say because Im the irish potato head that started this idea... THANK YOU !!! my friend for everything you are doing and all the hours your putting into testing !!

    I think getting this right will be a big challenge but thats why it will be worth winning !! :-)

    I also know there are other people equally greatful with your efforts Robert and also what the other chaps are also doing !!

    Tomorrow when Im back in the office. all my bosses are gone for a full week snow boarding... so I have an empthy office and a fantastic feeder project to hit on the head...

    I think it might be good if Robert we can chat a little tomorrow. a little more about your idea and whats the big issues... maybe we can help you.. and I hope you can help me with an idea im working on at the moment...

    So once again.. a massive irish potato head::: THANK YOU... have a lovely evening and dont do anything with this project tonight !!!... beer and tasty pizza !!! and then we can all start with a fresh head tomorrow !!

    Ian :-)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    @ bertho and calimb: Thank you very much for explaination!!! :-)

    I will take this into account when starting ABS tests.

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

     

     

    Daid? Did you see this?

     

    I haven't noticed but I don't change filament very often. Do you have *firmware* version 14.02? It fixes some bugs like this.

     

     

    Bug in the latest release. I have a fix on the shelve, will be in the next release. I have a few small Cura bugs to fixed, then I'll go into the UM2 firmware to fix some things there. I'll pack the 14.02-RC2 with a newer firmware.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Thanks for the encouragement. Yesterday was not a good day. Didn't get a good nights sleep, didn't eat right, things were going wrong all day and the UBIS conversion was the last straw. I just stepped away from everything, took a drive in the car and then watched some TV. Feeling better today :p

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Thanks for the encouragement. Yesterday was not a good day. Didn't get a good nights sleep, didn't eat right, things were going wrong all day and the UBIS conversion was the last straw. I just stepped away from everything, took a drive in the car and then watched some TV. Feeling better today :p

     

    Try and never let yourself get too tied up crazy with this stuff.

    Your a bit of a genius Robert.. a lot of us know that !! and Geniues work better with a clear head ! :-)

    So with a tasty marsbar in hand.. think... simply is beautiful... what are the main problems causing this and how can they simply be removed or changed for the better....

    Ian :-) :-)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    I highly recommend to look at Steve extruder ( abandoned now) used in SeeMeCNC-H1 printers. I use it about two years.

    It has double drive wheels(about 1/2" diameter) with smooth(!) groove. It is adjustable. It cannot eat filament but skips steps under high load. I used M3 bit to make grooves slightly "sharper". But with my J-head V1(smallest liquid zone) I never went faster than 100mm/min.

    There was bowden version also.

    I can openscading it if needed.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    what and where is the Steve extruder ? it sounds interesting.

    Ian :-)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    two questions for the group to start my creative day..

    (1) my grub screw that holds the drive to the feeder motor is just stuck like glue. I didnt think i tightened it too much.. whats the best way of loosening it up without breaking it?

    (2) Second question, is there anyform of rubber wheel that can tighly and securely fit onto the axis of the feeder motor ? im not sure how a rubber wheel could be tightened onto a round axis so it wont move.. ?

    Thanks.

    Ian :-)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Ian,

    Make sure you have a good hex wrench that does not have worn edges. If you do not have a replacement you can make it like new by carefully, without overheating, grinding off a few mm of the tip and the worn section.

    Rubber wheels normally have an aluminum center and a grub screw.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    (1) my grub screw that holds the drive to the feeder motor is just stuck like glue. I didnt think i tightened it too much.. whats the best way of loosening it up without breaking it?

     

    What usually works for me in that situation is using the same size torx screwdriver. :)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    Thanks guys !! :-)

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    what and where is the Steve extruder ? it sounds interesting.

    Ian :smile:

     

    http://reprap.org/wiki/Seemecnc_h1 see pics, pdf, STLs

    Acrilc parts were mistake. They are warped and break. But I printed replacements.

    When replicating do grooves less deep.

     

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    Posted · Ultimaker2 Feeder System - Improvements and Ideas

    It looks like ABS is a mistake for the UM2 feeder. It seems to slowly wear, which causes ABS dust to end up in the hotend and clog the hotend. We're working to get the supplier to change the material, but it's not going as fast as we hoped.

    A quick workaround is printing the sides in PLA, and use those instead of the ABS sides.

     

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