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Anders Olsson

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Everything posted by Anders Olsson

  1. Did you inspect other components for wear yet? I am curious since I did not print that much with glow fill yet, but my custom made abrasive filament had effects on several components: - The nozzle was worn down by about 1mm in height and the diameter increased to about 0.7mm after similar printing times as you reported. - The inner diameter of the teflon insulator increased to about 3.5-3.6mm (which actually seem to have reduced retraction related problems) - The knurled wheel got a bit rounded and the ball bearing has a rough surface where the filament is moving. - There might be some we
  2. I managed to ruin a UM2 nozzle in a very similar way when printing abrasive material. What I printed was something I would expect to be much more abrasive than glowfill though, so I am a bit surprised your nozzle look lite that after just 40 hours. When my nozzle was ruined, I put it in a drilling machine and turned it using a file until the flat surface was reasonably small again. You can get decent printing quality even if your nozzle diameter is like 0.7-0.8 mm, as long as the flat surface is not too large. You have to measure the true nozzle diameter and generate new files with that on
  3. Daid, would you mind having a quick look at this issue before next release? https://github.com/Ultimaker/Ultimaker2Marlin/issues/42 (Just try once to print the UM robot at 99% flow) I tried to read through the code to figure out what is going on, but I am simply not good enough on coding to get anywhere.. By the way, I managed to trigger the temperature sensor warning numerous times with the latest firmware. I first thought it was related to that I increased the maximum temperature to suit my polycarbonate experiments, combined with the larger mass of my custom heater block. But then I go
  4. DonMilne >> Yes, a flat FFKM-gasket would be better than an o-ring, but flat FFKM gaskets seems even more uncommon than o-rings. I think a thin O-ring would work, since it sits very close to the heat block which means the plastic stays reasonable soft there. 3Poro >> I used a glass filled teflon isolator. The only pure teflon isolator I had ended up too heavily modified for further use when I fitted the temperature sensor to it. As I mentioned, I suspect one of the parts is not perfectly flat and that is why it was leaking, I will have a look into that. Polycarbonate is quite t
  5. I have been printing Polycarbonate at 290-300C for about 6 hours now with the Vespel insulator. I had to stop since there was a strong smell of burnt plastic and I had to find out what was going on. It turns out there was a leak somewhere in the Vespel-area which soaked my heater block in polycarbonate :cry: The leak was most likely caused by one of the surfaces not being perfectly flat. I will investigate this further. When taking things apart I noticed that the teflon spacer seems to have survived the increased temperature: The slightly burnt surface on the teflon comes from nu
  6. I am almost exclusively printing ABS and here is what I recommend: - Fans has to be off . The only time I use fans for ABS is when I manually switch them on when printing tiny details in the end of the print. - The provided glue was not really good for anything in my opinion. I am using "Tesa Easy Stick"-glue now and it works really good for ABS (and almost too good with PLA) - The glue has to be applied when the buildplate is cold and the layer of glue should be rather thin. - Z-calibration (leveling of buildplate) has to be done so that the first layer really gets 100% infill. I prefer l
  7. I did some more testing of the Vespel insulator tonight. Initially it caused me quite some problems with PLA, but this was mainly related to the fact that my teflon spacer had 0.1 mm larger inner diameter than the Vespel insulator which caused major problems after retraction. After I drilled it to 3.3 mm it appears to be printing PLA fine. However, I still have a feeling that the Vespel causes some friction with PLA and that making it thinner would reduce friction. I managed to get a molten plug of ABS to stick inside the Vespel insulator too. (before I increased the inner diameter of it)
  8. I pricked up the Vespel spacer today, thanks again 3Poro! To get some idea of how it reduces the temperature of the remaining teflon spacer, I modified an old teflon spacer (not glass filled) to fit a temperature sensor. This teflon spacer was in bad condition already before I modified it, and making room for the temperature sensor did not improve it :???: So I don't know how realistic this test was, but hopefully it should give some idea about the improvement. I printed the Ultimaker robot in ABS at 260C, but I had to abort the print half way through because I was lazy to level the pl
  9. Thank you CecilieVF, that was most of the information I was looking for! I would still like to know more about the type of plastic, like which of the common solvents it can handle, UV-resistance, aging and so on. But I guess Formlabs is not going to tell us exactly what kind of polymer they are using. About the supports, how much overhang (in degrees) can you print approximately before you need supports? Printing objects which are truly transparent is interesting in fact, I have to look more into this.
  10. The #2 would work fine for me, I am happy to have that one if still available. :smile: I will PM more info.
  11. Time for an update: I had to keep the printer running lately so I did not have time to modify the heater block more past days. Two of my heater blocks are back in the workshop for improvements (waiting there for them to finish rebuilding the workshop) and one heater block is hopefully traveling south right now :?: :smile: That leaves me with the one I am using right now left. I have reconsidered the sensor fixing a bit, I think i will make separate cuts from the top where you can access the sensor/heater to help pushing them out if stuck. I had some concerns about heat transfer if I cut
  12. Are you by any chance printing at flow rates below 100%? There seems to be a strange bug in Marlin that does similar things to my prints if I go below 100%: http://umforum.ultimaker.com/index.php?/topic/7764-underextrusion-when-flow-is-set-below-100/ If this is not the case I guess something is wrong with your teflon insulator (deformed/too small inner diameter). Or your filament is too large or damaged from grinding.
  13. I haven't had any problems getting ABS to stick to the platform since I started using the "Tesa Easy Stick" glue. Using the fans is risky though, so I generally leave them off. When printing large objects I usually cover the front of the printer as an extra precaution, to minimize temperature gradients. The glue stick works well for that purpose too as you can see
  14. I really like the Form 1+ concept, but I am missing crucial technical details about the printed material. Has anyone seen specifications of the type of plastic, the maximum operating temperature of printed objects and the strength compared to ABS or PLA? This is kind of necessary information if you want to print parts for engineering applications.
  15. Does the temperature drop when the cooling fans start? In that case your heater block may be sitting too low, touching the fan cap
  16. Those "external shield" and "nozzle retract" -solutions look quite well functioning I have to say, but somehow a bit bulky and complex for me to really like them. What I had in mind is: Did anyone ever consider a valve inside the nozzle? I am thinking of something with the same operating principle as the thing old diesel engines has inside the fuel injectors. Of course we are dealing with plastic which even if really hot is much more viscous than diesel. But if I calculated correctly we would have up to about 70-80 bars of pressure inside the UM2 nozzle (?). So using a few bars for openin
  17. That stuff is highly interesting! I wish I had the skills to find this kind of material. I have been spending quite some time looking for plastics but my google skills are apparently not good enough :sad: The Celazole Pbi appears to be exactly the kind of material you would like for the thermal insulator. The non-stick properties might even mean you can get away with the whole insulator made in this material even for printing PLA. As for the Vespel, I was reading a bit about it an it worries me a bit is that it basically is a polyimide, just as Kapton, and ABS is well known to stick very
  18. I did some destructive testing on an ABS object which I had heated on the heated bed to 90C. While it still feels solid at 90C, it permanently deforms rather than flexing when you put some load on it. So I would not use Ultimaker ABS above 80C. I would love to have ABS that keeps it's mechanical properties above 100C but I doubt that you can buy such ABS as a printable filament (?) Polycarbonate is what I aim for when it comes to printing objects that can resist high temperatures.
  19. I wanted to test the Ultimaker Original nozzle because it is rather large compared to other nozzles, probably among the largest M6-threaded nozzles there is on the market (?). So if the heater can keep up with that one there is possibly a whole range of M6-threaded nozzles from different manufacturers that would work with this heater block. The nozzles look a bit different inside, which might affect things like oozing, so it could be useful to have a range of designs to choose from to improve a future dual extruder upgrade for example. Initially, I designed the heater block for the U
  20. I tried with retraction off and it behaves exactly the same way, so it has to be something else. As I said, it happens when the flow is reduced because the head changing direction often. It then more or less stops the feeder instead of slowing it (of flow is less than 100%). I like the flow setting because it can be adjusted on the fly. That way you can optimize the flow for a particular filament first time you print with it and get a really nice result at first try.
  21. I am happy to announce the brand new Ultimaker 2 Original :smile: :smile: Thank you Daniel at 3Dverkstan for the nozzle and other useful parts. To my surprise it worked quite well with the much larger Ultimaker Original nozzle. I tested heater by setting the fans at 100% and increasing the temperature to 260C. It managed to reach 260C and kept the temperature stable, but it was obvious that I was using most of the heating capacity then. There seems to be quite some interest in this design, so I will try to get a final version manufactured and tested. This will take a few weeks tho
  22. I made a very simple test today to confirm this issue: What you see is how the extrusion is suddenly not working properly when flow rate is decreased from 100% to 99% The feeder motor more or less runs on/off, meaning the motor stops when the head is changing direction often and flow should be reduced. I will put this issue on github
  23. Funny, I have been thinking a lot about designing some kind of valve like this lately. As you say, it seems like the only way of solving the oozing problem permanently. It might not be as difficult to design a valve like that as one think actually, the pressure it needs to handle is very slight after all. I wonder how Stratasys solves this problem by the way? Maybe one could sneak in and spy a bit at one of them at work.. :smile:
  24. I have a number of things I would like to test with dual extrusion, but need it to be fairly reliable to be interesting to me. The ability to use two colors in the same object is interesting of course, but that is not the main thing I have in mind. More interesting is when you think of for example having transparent and non transparent plastic in one print. And much more interesting if you could use conductive and non conductive plastic. For practical uses you would prefer much lower electrical resistance than the plastics you can currently buy, but I think such plastic can be made with th
  25. I never remove the nozzle if it is blocked. Instead, heat the nozzle and push a wire from a wire brush inside the hole from below to clear it. Manually feed new filament through the nozzle. Repeat until the filament is flowing freely. If there is something that repeatedly blocks the nozzle and can not be pushed out, I usually use nylon filament (Taulman Bridge) . Push it through until there is nylon flowing through the nozzle. You will have to use the wire-brush wire to unblock it repeatedly. Then lower the temperature to 140C as you continue pushing filament through. It will stop flowi
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