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Anders Olsson

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Everything posted by Anders Olsson

  1. Strange topic maybe, but here is what I have noticed: I sometimes use the flow setting to tune the extrusion rate for varying filament diameter. It is quite convenient and works really well. However, tonight I had some really odd underextrusion problems. I am using slightly large Velleman ABS filament so I had the flow set to 97% to compensate for larger diameter (exactly 3 mm) I tried both changing nozzle and cutting away a part of the filament. But the filament was moving nicely through the bowden and everything else looked fine. I had been printing two hours and underextrusion just s
  2. Yes, a 3D-printed fan cap is an option of course. Nice design of that one by the way. You would need the hole for the nozzle to be at least 11 mm if you want to fit a 7 mm socket there to remove the nozzle without removing the fan cap by the way. I made some changes which means the heater blocks I have right now does not fit perfectly. Therefore I would need to get a new version manufactured and tested before releasing anything. That is probably not going to happen until earliest next week though because they are rebuilding the workshop I am using. My experience with sharing incomplete dr
  3. Here is the dimensions of the original heater block compared to the one I am currently using: I thought I made the new block 1 mm thicker than the original one, but it turns out it was just 0.5 mm which means you can only save 0.25 mm by making it thinner. EDIT: You can save 0.5 mm of course. I would not go thinner than the original heater block for manufacturing reasons. As you can see the E3D nozzle is about the same diameter as the hole in the fan cap. (I added the fan cap in paint, but the hole is approximately 8 mm just as the maximum diameter of the nozzle key grip) This means you
  4. Based on my experiments I would probably keep the PTFE insulator as in the photo. PTFE has several very interesting properties. It has low friction and things does not stick to it easily, but even more interersting is that the coefficient of friction decreases with increased load (!) I think those properties is the key to why it is so difficult for any other material to compete with PTFE when it comes to handling molten PLA. The plug of molten PLA that forms when you have backpressure from the nozzle will not only be unable to stick to the PTFE, if you push harder the PTFE will actually bec
  5. Well, the main space issue is the length of the threaded tube and the fact that you need some material above the nozzle to keep the thing together: (This is an old version, I did not have an updated assembly) The length of the nozzle only really determines the length of the heated zone. One could think of other designs where the sensor and heater are moved up, but that may complicate manufacturing quite a lot. You need to cut those M6x0.75 threads somehow. Easiest would be to simply shorten the threaded tube a millimeter or so, then there would be plenty of space with the latest design.
  6. Some results from tonights testing: There is quite some oozing if i pause a print. If I use the move material function and retract the filament more, like 25-30 mm, there is much less oozing, but at least for the blue PLA I could not completely prevent it. It feels like one could investigate other approaches than just playing with nozzle design and retraction to prevent this though.. I completed the extrusion test with the blue PLA at 210C (!) Destructive testing showed that bonding was good up to 7 mm3/s The 8 mm3/s and above could be separated from each other easily and for 9 and 10
  7. Hi Jan :smile: 1. The idea with screw and the toothed washer is to fix the sensor and heater in an appropriate way, clamping them with the screw and using the toothed washer as a spring to even out the force. It seems to work okay, but I have done very little testing so far. This design also relaxes the demand on manufacturing precision compared to the previous design where the screw hole had to be perfectly centered between the sensor and heater holes. The screw hole is D-shaped and the idea behind this is that you can access the heater and sensor with a screwdriver and push them out in
  8. I actually have a few of them made already, but I need to do some changes to the design, so I may end up using them for that purpose. The space is very limited as you probably know already, so even though I made the new heater block as tiny as possible I had to add a 1.5 mm spacer below the threaded tube just to fit things. I hope that some minor modifications may make it possible to fit it without spacers or machining of other parts, but I am not sure yet. I would also like to test if there are signs of heat transfer problem when the nozzle is extended like this. And I need to check if th
  9. Here is one more photo I luckily have access to a really good workshop, so I just designed it and they managed to manufacture it for me. There is a toothed washer which distributes the force from the screw head onto the sensor and the heater. I don't know if this is a final solution, but it seems not worse than the original design at least. Regarding the teflon spacer I would like to get rid of that one to, but the spacer is much less of an issue for me than the fact that I can not easily change nozzle. So I tried to solve the most urgent problem first. :smile: I can provide more
  10. Update 2015-04-12: - The heater block can be ordered here: http://www.3dsolex.com - Further information about ordering and installing the custom heater block can be found in this post: http://umforum.ultimaker.com/index.php?/topic/7689-custom-heater-block-to-fit-e3d-nozzle-on-ultimaker-2/?p=95991 - Some more things to keep in mind when installing the custom heater block: http://umforum.ultimaker.com/index.php?/topic/7689-custom-heater-block-to-fit-e3d-nozzle-on-ultimaker-2/?p=89581 Hi! I have printed some very abrasive home-made filament lately which eats my expensive UM2 nozzle a bit too
  11. While looking for other stuff, I found flame resistant ABS filament here: http://filaments.ca/collections/flame-resistant/products/flame-resistant-abs-filament-1kg-spool
  12. I bought some stuff from E3D a few weeks ago and among other things I added a roll of clear polycarbonate: http://e3d-online.com/Filament/Engineering-Plastics/Polycarbonate-Clear-300 It said printing temperature 280-310 C on the home page, so it is out of reach for the UM2, but I added it just in case I rebuild the printer to print at higher temperatures in the future. However, when it arrived it said printing temperature 250-280 C on the roll, so I immediately fed it into the UM2 for a test print The print came out perfectly fine, no signs of problems with bonding between layers or su
  13. I had to take my car to the yearly inspection yesterday and while they had some things to complain about they did not notice that the sway bar is attached by a 3D-printed link on one side. :cool: It was covered in dust though, not shiny as in the photo, so it is not immediately obvious. I printed this strengthened sway bar link two months ago after having two original links failing in about one year. I added a few millimeters in all directions and printed it with 100% infill. At first, I considered this as a temporary fix and a suitable way to test the engineering properties of the U
  14. At first, I thought it looked like a great deal, but after reading the details I could not figure out what I would use the new filaments for. I am confused as to why they select to develop so many new filaments with such similar specifications. The product range in the kickstarter project somehow does not fit either as engineering plastics or as plastics for printing art. I completely agree that Taulman should sell colored filaments. That kind of semi-transparent look of nylon is really not that appealing. Although color is theoretically unimportant for functionality, I feel it would be ha
  15. I have done quite a lot of prototyping an production of small series of components for the lab where I work. I only use ABS, here are some reasons why: - The maximum operating temperature of PLA is a bit low for engineering purposes. - PLA is a rare plastic outside the 3D-printing community. ABS is well known, which makes it easier to convince people that the printed components are just as good as injection molded things (I usually mention that LEGO is made form ABS) - The reliability of my printer has been much higher with ABS. I had lots of issues with random underextrusion with PLA whil
  16. Download the latest Cura here: http://software.ultimaker.com The UM2 firmware comes with the Cura software. Then connect your UM2 to the computer with the provided USB-cable, start Cura and select the upgrade firmware option.
  17. Strange. My UM2 has always been extremely reliable with ABS but not very reliable with PLA. A few things that I have sorted out so far: - Upgrade to 14.07 firmware. The the new priming cycle eliminate grinding issues at startup and the leveling fixes makes regular leveling unnecessary. This upgrade probably reduced the number of aborted prints from 30% to 5% for me. The improved priming also made it possible to reliably print slightly large diameter filament, like Velleman ABS, which are close to 3mm. Before 14.07 the grinding when priming caused enough damage to the filament to get it s
  18. Interesting! As I said previously, I was planning to do further tests with metal spacers. Time has been limited though since I need my printer up and running for my business too. However, I tried another cooled metal spacer which looks like this: Suprisingly, it worked fine with PLA from start. Then I realized the reason why it worked was that the spacer was pushed up because the spring I used was to weak. This meant a thermal barrier of PLA had formed between the spacer and the nozzle, helping to keep my metal spacer cool. Not the kind of solution I was looking for :smile: With a st
  19. I have done some experiments with various metal spacer designs lately. The conclusion so far is that with ABS more or less anything out of metal will work as long as is it kept reasonably cool. PLA is a completely different story. I kind of consider PLA as the root of all evil after seeing what it does inside the spacer :cry: It is not so much friction that is the problem, it is the fact that PLA softens into a rubber-like state at very low temperature. When the filament softens like 10 mm inside the spacer and you put it under pressure, the diameter of the rubbery part will increase. Th
  20. I used the fins from an old heatpipe-based PSU heatsink and put them on an aluminum pipe which happened to have the right dimensions.. I had a spring that could be cut down to fit where the old spring was. Here are two more photos: The last photo is taken after five hours of printing. I thought it would be full of ABS by then, but it was absolutely clean. There is no guide for the bowden tube to align it with the hole of the aluminum pipe and I think it draining most of the available heating power from the nozzle when running at 260C. But it worked fine with ABS. I will try to
  21. I was inspired by the attempts to make a metal spacer so I came up with this thing today: It has been printing for five hours now with like 1000 retracts and has been working perfectly so far. (printing ABS at 260C) I will take it apart tomorrow for some improvements and inspection.
  22. I had plans to let a local workshop manufacture a UM2 heater block that would accept UM1 nozzles a few months ago. Other things became more urgent though, so that project is on hold. Here is a 3D-model of the original components that I made: The UM1 nozzle dimensions are approximate. As you can see, the heater block will have to be a bit larger to fit the UM1 nozzle. It may be a good idea to increased some of the dimensions to improve the thermal conductivity to the nozzle too. You will need to drill a larger hole in UM2 fan plate too, to fit the nozzle. When I was thinking about this
  23. I have been using the latest firmware for some time now and it works really well. The improved priming works perfect for both Ultimaker and Velleman ABS and I can use filament which is close to 3 mm now when the grinding when priming is gone. I am also quite happy with the leveling, however I have one more question regarding this. The calibration cycle uses 0.05 mm steps for both the coarse and the fine tuning. Is there some particular reason not to decrease the step size when fine tuning to lets say 0.02 mm ? I feel that the mechanics of the UM2 is precise enough to take advantage of a s
  24. I recently cleaned my happy corner, so here it is: It does not get more clean or organized than that. My wife seems to have no problem with that luckily :smile:
  25. Hi! As I am waiting and hoping that the issues with the UM2 dual extrusion kit will be solved soon I have been trying manual filament change when print is paused a few times. It works okay but is a bit complicated with the original extruder. I was just thinking, could an automated function for filament change in paused mode be added? (In case some one here with programming skills is out of ideas) That would make the UM2 more interesting I think and could be quite useful for me at least. It would be convenient if the loading cycle ended in a non grinding priming until interrupted by the us
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