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mendells

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Posts posted by mendells


  1. Hi, Christopher here. (One of the designers of the Bondtech DDG)

    I’m happy to answer your questions ;-)

    Regarding print speed: Early on in the development phase I created a quick speed performance test. The result of the test can be seen in the picture below. The same G-Code file was used but the extruder/feeder changed.

    Bondtech-DDG-comparison.jpg

    The test shows, that the Bondtech DDG is able to push with more force then the Ultimaker factory extruder. Therefore you may increase your print speeds, but please be aware that the Bondtech DDG is only one part of the equation.

    A prominent speed increase can be seen if your print flexible filament. I print Ultimaker TPU @50mm/s without any issues. May print speed of the the Ultimaker factory extruder is about 25mm/s.

    Cleaning: In theory the UM factory feeder may need  to be cleaned less often. In practice I would say it’s the same. Martin and I chose to include a small window for the user to check if the gears need to be cleaned. Cleaning can be done exactly the same way.

    Main benefit of the upgrade is the improved reliability. From time to time I also encountered grinding and slipping like latreides. Especially if you print at bigger layer heights. Since the first prototype of the Bondtech DDG I haven’t had any!

     

    Hi Christopher,

    Thanks for the information!

    Could you provide some more specifics on the settings for the speed test image? What layer height, print speed, and material were used?

    The Bondtech feeder does seem to be a big improvement and we do print a lot of TPU here so it probably makes sense to upgrade.

    Thanks,

    Scott


  2. Though I have not seen the DDG irl it's seems to me it has one disadvantage over the old bondtech models as you can't reach the gears for cleaning. The bondtech type drive-wheels do pollute (fill up with filament) sometimes. Not a big issue, I use and like the bondtech myself on one machine, but it does need cleaning once and a while. Of course you can also take apart the new model, but it's less easy.

     

    Thanks for the input. I already take ours apart every 6 months or so for cleaning so it isn't a big concern but it is something to think about.

    Have you been able to increase your print speed at all or are you just seeing more reliable prints?


  3. I was wondering what kind of speeds users with Bondtech extruders are using? My print speeds are fairly low as I have seen quality issues when printing above 40mm/s (using 0.4mm nozzle and 0.1mm layers) and I was curious if Bondtech users have been able to print faster without quality loss?

    I also noticed they have a new extruder (DDG) for the UM2+ that uses much of the existing UM2+ extruder components. Other than being a slightly lower gear ratio than the QR extruders (311 steps/mm vs 492.45 steps/mm) the drive mechanism is the same, so for $70 less the DDG extruder seems like a good deal.

    http://shop.bondtech.se/ec/upgrade-kits/ultimaker/ddg-extruder_ultimaker2_en.html

    149257822-origpic-a6b086.jpg

    149257822-origpic-f05372.jpg


  4. Is the tinkergnome "filament_sensor" the same or similar to the marlin "filament runout sensor"? I just got a Filament Sentinel and I'm trying to figure out how to update our firmware to add it in(I am not a code guy and so far it's all been a little out of my comfort zone). I noticed there is a "FILAMENT_SENSOR_PIN -1" in the pins.h and "FILAMENT_SENSOR_PIN=30" in the package.sh (which I cannot for the life of me figure out how to make work).

    So i'm just wondering if the filament sensor is already set up and If I can just plug the signal pin into PC7 and have it work without having to load new firmware?


  5. They have an UM2/UM2+ kit that just replaces the stock feeder so I would assume it's still a bowden setup. I have found the stock extruder slips with TPU/TPE filements. I have some SemiFlex and standard NinjaFlex and I can't get those to print because the feeder just slips before enough pressure can be built up. I've only really had success with NinjaTek Cheetah and Armadillo. Do you see any improvement with the bondtech vs the stock feeder with ninjaflex or are they comparable?


  6. I've been printing with Cheetah for a while now with varying degrees of success. BuildTak sheets help a lot in keeping parts stuck to the bed. My usual print settings are:

    Print Setup:

    Nozzle: 0.4 mm

    Layers: 0.2 mm

    Speed: 20-30 mm/s (all)

    Fill Gaps Between Walls: Nowhere

    Retraction Extra Prime Amount: 0.128 mm^3

    Material Settings:

    Temp: 235º

    Bed Temp: 70º

    Fan Speed: 100%

    Flow Rate: 130%

    Retraction Length: 6.0 mm

    Retraction Speed: 20 mm/s

    I have had some success printing smaller layers but if there are too many retracts it begins to under extrude and if you reduce the retraction length you get a lot of stringing. I've thought about buying a Luzbot just for doing Ninjaflex as it has a direct extruder instead of a bowden.

    Edit: Thought I should add that I've found keeping the filament dry is critical. Any moisture will cause under extrusion.

    • Like 2

  7. Has anyone tried replacing their XY motors with a 0.9º stepper motor? I found one that should fit (or require very little modification) but wanted to know if anyone has already tried this? My goal is to increase the accuracy to be able to hold +/-.001" (0.025mm) tolerances on parts. I usually print at slow speeds (20-40mm/s) so I'm not worried about the loss of speed.


  8. I finally got the new glass and it is far better than the stock Ultimaker glass. The original glass varied by about .020" and the new glass only varies by about .004" (I'll get a new video when I can).

    I have also found that the parts also stick much better to the glass. I'm not sure why exactly but I would guess that it is because there is more even pressure across the bottom layer as the part cools.


  9. Yes I am aware that this method is susceptible to other factors including the rods being bent or the frame bring off but it does show the difference between the flat glass and the warped glass. I have checked both sheets on a grant slab with an indicator and the ultimaker glass is significantly warped compered to the borosilicate. You are correct in that the borosilicate glass is not manufactured specifically for flatness but is is significantly better than the stock glass regardless. I have also noticed a change in the flatness of the ultimaker glass at higher temperatures (60-100C), but this may be due to the aluminum it's mounted to not necessarily the glass itself.


  10. I have always been fighting getting the build platform level and finally made a dial indicator holder and wrote a program to help me level the bed. Now the leveling procedure initially checks positions as close to the adjustment screws as possible, then checks the same pattern but closer to the center of the build platform. After that I have it "scan" the bed in the X and Y directions. I have dialed the bed in as close as possible but it is very apparent that the glass is warped. We have 4x Ultimaker 2+ and all the beds are wrapped to some extent but this one is one of the worst. I have sourced some thicker/flatter borosilicate glass that hopefully should be here in two weeks. I will update again once I have the new glass.

     

    • Like 2

  11. I have been having this issue for a long time now and have adjusted my models to make everything work but its been bugging me recently so I thought I would post and see if others have been having the same issue.

    When I print a part the internal and external features of the part are about 0.12mm (.005") too small regardless of the feature size. So If I print a 10mm box and a part with a 10mm square hole both features will come out about 9.88mm. The same thing happens with a 20mm, 50mm or even a 100mm part, they all come out small. I have tried this with all four of our UM2+ printers and multiple materials all with similar results. I could understand if the exterior features were small and the internal features were big (under extrusion or incorrect line width) or if the internal feature was off less than the external feature (material shrink after cooling) but I cannot for the life of me figure out how a 20mm box with a 10mm square hole could be 0.12mm too small on both features?

    Anyone else experience this problem?


  12. Just thought I would share the cabinet we made at work for our Ultimakers. The cabinet can store up to 6 Ultimaker 2s (less if you have the extended versions), has room for 64 boxes of filament (we use ColorFabb mostly), sealed and temperature controlled, and has pull out shelves for easy access.

    It wasn't cheap and its very heavy but its a lot nicer and cleaner than the wire rack we were using before.

    IMAG0498.thumb.jpg.c1316f63d190b3a421e1fe6f1a1428bd.jpg

    IMAG0499.thumb.jpg.321a371e280d345e78ed694506e1a141.jpg

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    • Like 6

  13. I have been having issues using combing on parts with internal "holes" for some time now but it seems more prevalent in Cura 2.1.2. Sometimes during combing moves the nozzle will pass directly over a hole in the part leaving blobs of plastic. It doesn't happen all the time and often times will only affect a few holes in the part. Usually I can get around this by disabling combing but that increases print times and noise. Anyone else having this issue?

    CuraCombingIssue.thumb.PNG.0b71c7c308b9ced9c4ddd72f01ca1c35.PNG

    CuraCombingIssue.thumb.PNG.0b71c7c308b9ced9c4ddd72f01ca1c35.PNG


  14. I've had some success using NinjaFlex SemiFlex filament and the geared extruder. I have to slow the print speed down to 40mm/s and It still occasionally has issues where the filament will twist inside the bowden tube and cause it to jam but at least its printable where its been impossible with the stock geared extruder. I've been using the larger 0.8mm nozzle and that seems to help reduce the pressure inside the tube which helps print reliability with flexible filaments.

    • Like 1

  15. I've run about 1500g of XT-CF20 using one hardened steel E3D nozzle and I am starting to see some visible wear. The length has only changed by 0.06mm (.002in) but the tip has rounded out fairly significantly. While it hasn't had a huge impact on printing performance it has changed it a little. Prints tend to curl or show some signs of under-extrusion. While this isn't ideal it is still a vast improvement over the brass or even the stainless steel nozzles.

    565c6efe6b73c.jpg

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    565c6efd619ba.jpg

    • Like 3

  16. Hi Mendells, nice work with the extruder, I know very well the amount of work that needs to be done developing this.  Since you discuss filament deformation I thought I would show you a photo showing how the filament gripped by the Bondtech Extruder looks.

    For your information I have just released the new QR model with a QuickRelease for quick filament changes.

    I am getting quite a number of happy Ultimaker users that have upgraded to the Bondtech Extruder that have made a fantastic printer even better and more reliable. Here you can see a happy user in France that have the predecessor the V2 model installed on his 3 printers.

    Please feel free to ask questions and I will be happy to answer them!

    With Best regards

    Martin.

     

    Thanks for the feedback Martin. If anyone knows how much work it is, it's you ;)

    That's about the same depth of deformation I am seeing with my wheels although the deformation shape is a little larger due to the bigger pitch of the gears and the drive-groove location on the gears themselves. Having a driving wheel on both sides of the filament seems to help tremendously with the grip and reducing grinding. I have not been able to get my filament to slip in the drive gears at all. The motor skips steps before any slipping/grinding is possible. I'm assuming its the same way for your extruder. The original UM2 feeder had been a source of much frustration from the beginning.


  17. Hi mendells, I'm running with Carl's 35W heater, and like you with the origional 25W heater I was getting the error when the temperature drop 10 below the set temperature. The testing I have done with these two sets, the nozzle dropped just 2 degrees with the notch set so the air is flowing mainly to the part with just a small amount to cool the new material.

    This has evened out the cooling of the Robot print with both ears, antenna and bringing looking better.

     

    I've been debating moving to the 35w heaters. How has your experience been using them so far? Any issues?

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