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mendells

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Posts posted by mendells

  1. I've had to replace a few build plates after chunks of glass came off. It only happened when printing with ColorFabb XT and only on prints with very large bottom layers. The XT sticks well enough to a heated bed with PVA glue that when it cools it can take chunks out of the glass. I've found using a thicker bottom layer helps and not allowing the bed to cool below 35-40C helps prevent damage. I've tried XT with the buildtak and it has similar problems where it sticks too well and damages the buildtak.

  2. They are very similar, the only real difference is the BondTech feeder uses hobbed gears to grip the filament where mine uses a V-groove in the gear teeth themselves. The V-groove should deform the filament less than the hobbed style, but without actually having a BondTech extruder its hard to know for sure. The motor I am using is a little stronger than the one they use but both should provide ample torque.

    BondTech

    25618003-origpic-1f2e39.jpg

    Mine:

    55fb159a653a6.jpg

    • Like 2
  3. One of our UM2s started acting up today. The screen will freeze soon after the print starts. The input wheel does nothing but the part is still printing fine. When the part is done printing it will retract a few mm but then stop. The screen is still frozen and the input still doesn't work. I have to power off and restart the printer to get things working again.

    Any ideas what might be causing this?

  4. Wow, that looks a lot cleaner, from aesthetic standpoint. Only thing I see would be wiring clutter, if its flipped to that side. Also, hard too see from the pics, but would there be a place for a grommet at the bottom where filament enters the feeder? (Similar to the iRoberts feeder)

     

    I'm still working on cleaning up the wiring but I think I could make a channel in the mount to help clean up the wiring a bit. I don't currently have a grommet but I'll be sure to add one in.

    Also just playing around with some ideas.... ;)

    56423cd4a6aed.jpg

  5. This change looks like it would no longer need the filament guide, and also shorter bowden distance! I'm a fan!

    This may be another topic, but in the case of detecting stuck/empty/tied filament, would there be a way of accomplishing in such a short distance?

     

    I believe there would be, and if not the location of the feeder could be moved to accommodate. I may make a "reverse" version of the gearbox so I could mount it with the motor on the left and the gearbox on the right. That way it could sit flat and would provide a bit more space if you wanted to add a detector later on.

  6. I'm pretty sure you can get most of those improvements from a simple hobbed-wheel change...

     

    Its possible you could see some similar benefits from using a hobbed wheel instead of the knurled one Ultimaker provides but there are some disadvantages. The gears work in a similar fashion if you were to use two hobbed wheels but with the addition of the geared motor you can apply a lot more clamping force to the filament without stalling the motor. The gear "trench" design also allows for a significant amount of grip force to be applied to the filament without significant deformation, even after retracting over the same spot over and over again. Our old makerbot replicator used hobbed wheels and they still had filament grinding issues.

  7. What settings do you use for the hardened steel nozzle combined with the CF20? Speed, layer height, temp, ....

    cheers

     

    Well with the gear feeder and fan shroud I using:

    Material Settings:

    Print Temp: 240C

    Bed Temp: 70C

    Fan Speed 50-100% (Depending on part size and detail)

    Cura Settings:

    Layer Height: 0.12mm-0.1mm

    Print Speed: 40-50mm/s

    Initial Layer Thickness: 0.24mm

    Initial Layer Line Width: 110%

    Full Fan On Height: 6.0mm

    I also use a diluted PVA (elmers glue)/water blend on the bed to help with adhesion.

    Good descussion on printing with XT-CF20 here: https://ultimaker.com/en/community/view/17159-printing-with-colorfabb-xt-cf20-um2?page=unread#unread

  8. Looks like a good idea, I'd just be concerned what adding all that weight to the head would do. Might be worth looking into beefing up the XY rods, adding bigger bearings as well. We have an old MakerBot Replicator that I plan on modifiying with an E3D hotend and gear feeder. The XY stage on the makerbot is more rigid but cant handle the same sort of acceleration/speed the Ultimaker can.

  9. The Kapton tape does help reflect some of the heat. Also Colorfabb XT-CF20 would be my preferred material. The added carbon content helps prevent deformation due to heat and helps "insulate" the plastic. Regular XT may hold up just fine but if you have the option, go with the XT-CF20, oh and make sure you buy a hardened steel nozzle as well. I actually use the steel nozzle for both XT-CF20 and regular XT.

  10. There is a lot of work to do before production so I don't know for sure when that may be.

    A question for those who may be interested. Would you rather?

    A: Receive all hardware and print the gearbox, motor mount and motor adapter yourself ($100-150)?

    B: Receive all hardware and 3D printed gearbox, motor mount and motor adapter ($130-180)

    C: Receive all hardware and machined aluminum gearbox, motor mount and motor adapter ($200-250)

    Prices are rough estimates, just trying to get an idea what people would want.

  11.  

    My own (shameless self plug :p). It makes a big difference in the cooling performance and reducing heater errors.

     

    Yeah. I've got my eye on these:

    https://www.youmagine.com/designs/um2-olsson-block-fan-mount

    https://www.youmagine.com/designs/um2-fanmount-blizzard-6718ce34-c069-4204-875f-dc0f15989b53

    https://www.youmagine.com/designs/fan-mount-um2-olsson-block

    https://www.youmagine.com/designs/ultimaker-2-fan-shroud

    https://www.youmagine.com/designs/support-ventilo-pour-olsson-block-nouvelle-piece-centrale

    My criteria:

    - The fan mount should print well without support material.

    - It should not be any bigger than the original fan mount. Some of the designs out there are larger and require further modifications to make sure that they don't "crash" when approaching the extreme edges of the build area.

    - It needs to "cover" the heater block to prevent temperature errors due to airflow on the heater block.

    - It needs to have strong mounting tabs. I printed one a while ago and the tabs snapped off before I had a chance to install it.

    Any other suggestions?

     

    Those were my criteria as well. My mounting bracket fits within the stock fan mounting bracket "area" and does not require any modifications. It also covers the heater block and the tabs are plenty thick enough (my first attempt was to thin).

    As for printing well I've only printed it with ColorFabb XT-CF20 but it prints beautifully without supports. I would think that regular XT would work as well but my suggestion would be XT-CF20. The plastic shroud also helps eliminate annoying vibration noises.

  12. Printed a few doorstops with the gear extruder and Olsson block. The 0.8mm nozzle and 0.4mm thick layers makes a sizable dent in the print times. The print time went from over 4 hours to just over 1 hour. The gear extruder could extrude faster but the heater isn't strong enough to keep the nozzle hot.

    563a613399dc5.jpg

    563a613517916.jpg

    .4mm nozzle,

    ColorFabb XT

    0.12mm layers

    70mm/s

    Print time: 4h 34m

    .8mm nozzle,

    ColorFabb XT

    0.4mm layers

    50mm/s

    Print time: 1h 4m

    Nonlethal Door Stop

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