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Everything posted by JohnInOttawa

  1. Thank you. Your comment about slowing down in corners resonates - these are small teeth and corners are exactly where things are getting messy. I'll try to explore ways to change how that path is laid down. If it was CNC I would know how to change that toolpath, but I don't have that skill or knowledge (yet) here. Fortunately, there are some smart people to ask here ? For a dummy tower, is that simply a matter of creating a separate STL and importing it to Cura, or can I do that within Cura itself? Thanks again!
  2. Well said. Looking forward to the next chapter of fractal land ? J
  3. Well, that discussion would occupy an afternoon and more than a few cups. While I make my living from math based stuff, it would be a cold and barren pursuit if not for art. At least for me, if not for those things that remind us of beauty, I'd soon forget to look for it in my struggle to get everything done. The other night I was passing an isolated thunderstorm over northern Canada. Alone in the dark, the cell was lit continuously from within by lightning, the intensity of the storm created an ionized glow immediately overhead, while still further aloft was a green, dancing curtain of northern lights. All the way from the ground to space appeared to be lit up. Our aircraft and systems are an engineering marvel. Could not hold a candle to that vista. Art wins, at least IMO. Cheers J
  4. I'm always taken aback when I see creation in progress. The revisualization (if that is a word) of an abandoned fuselage into something that could be the centrepiece of a sci fi show. Pretty neet. I look at that same original photo and think about how salvageable that build could be, what would come of corrosion or stresses on parts that were only supposed to be in their current state for a few hours, instead of the months or years it has been. Which is why I make parts with my Ultimaker, while you make art! Thanks for sharing. J
  5. That looks like AN225 number two taken in the Ukraine..... John
  6. This thread is related to my nylon printing 'adventure'. The part of the print I am struggling with is an upward facing gear-toothed circle. It looks like the print is suffering from severe overextrusion and the nozzle is dragging material out to the perimeter. Replaying the layer view in Cura, I am starting to wonder if the line width required for these gear teeth is narrower than I have set. I'm using a 0.4 nozzle currently, have adaptive layers in use per a suggestion here and that has improved things somewhat. Base layer height is set at .05 and width at 0.4. When I look at how it tries to print that, I can imagine why there is excess filament. When I increase line width to 0.45, it looks better in Cura. I imagine it will slightly underextrude and that might offset whatever is going on. Of course, if underextrusion is what I am doing, I would rather not do that do the rest of my print. Can I set up a line width change to start at a specific layer? Thanks once again... John
  7. Appreciate this! I will isolate that part of the print and try it again on Thursday. I had not considered adaptive layers and will adjust retraction, will post the results back here. I had also slowed down my print speed, maybe too much. I'd welcome advice on what others have found to be optimum. John
  8. Sorry I didn't add it earlier, was soaking out the PVA. Post is updated with the print pic. Thanks again John
  9. First part is done, new day, new design, new question! I'm printing a part now that has a circular 'dog', upward facing teeth around the perimeter. Cura showed no issues, but, while the rest of the print turned out fine, the toothed ring turned into a nondescript raised roughened, mostly melted, area. I'm pretty sure I am missing an essential technique for managing the small, rectangular pyramids that represent each tooth. I ran a 0.4 AA core, Ultimaker black nylon, 0.1 layer height, 250C and no fans. Thanks in advance! John
  10. Sooooo Good news and 'learning'. Glue stick (with good advice applied, thinned out with a damp tissue), worked perfectly. Flat, no warping, came off without taking any glass afterward. 'Learning:. Ironing. I had slowed down the print speed to ensure the quality was where I needed it. Worked great. But then I decided to tick 'ironing' at similary low speeds, on a piece with lots of corners. From the already pretty good finish, Ironing produced three distinct textures. At the start of the corners, surface quality was slightly better than non ironed. Mid length lines were amazing, just about zero discernable lines. But then we got to the corners on the end, and, well, it just created a melted blob, effectively destroying what needed to be a flat surface. No biggie, this wasn't intended to be the final print anyway, just checking dimensions, but note to self. Easy on the ironing with nylon. (BTW this effect worked perfectly on the PLA version of this print). Thanks again for the advice! John
  11. Thanks gents! I bought a glue stick and will try out the slurry. Thought of doing it this morning, but thought it might take some time for the first run. Of course, with the printer tied up for the rest of the day now, I guess I have time.... Much appreciated. John
  12. dumb question of the day - no longer have the original glue stick. Which ones use PVA? As an aside, I must be the only woodworker I know who no longer has any PVA glue in the shop. Everything has additives that I probably don't want on my build plate. If there was an anti-matter version of perfection, I would achieve it.... Thanks John
  13. I understand you have kept your filaments in bags with dessicants. That might not be enough. How long ago was the PVA first used? To my eye, it does have the look of humidity. I use a filament dryer, dried my PVA completely two weeks ago and sealed it with fresh dessicant. I could hear it popping as it printed today. One area of a support failed the same way as print #1. Just a thought..... John
  14. That sounds like a good plan. Thanks! John
  15. Good morning. I just finished a job with Colorfabb Woodfill on my UM3. I ran it with a hardcore 0.6, results were better than expected, good adhesion, excellent surface finish, sanded to smooth and accepted stain without any unexpected blotches. Now, my prints were simple, no overhangs. But so far, so good. John
  16. Just curious if this is a workable option. I have a piece that I would rather not use PVA for support if I can help it. Just not sure if PLA will work and what I might get in terms of interface (adhesion, removal, print quality). Thanks in advance! John
  17. That HDGlass experience is concerning. I'll look out for those alternatives. I do have a roll of the HDGlass on hand that I am unlikely to find a home for, will give it a try and post results. Might just be an incompatible choice for the ultimaker. Thanks again John
  18. That's a good consideration. I hadn't really fleshed out my thinking enough to consider the case of of removing a print core mid print, more I was picturing hauling on this thing while doing a cold pull and the stress that puts on the rods and blocks. Right now my RAM (which at my age stands for 'randomising aging memory') is full, trying to figure out the interface and whether there should be cooling for the upper print core. I'm also considering whether, since we have control of the environment, it would be worthwhile to allow the stand to tilt so that the nozzle could be horizontal or pointed upwards for cleaning, for those cases where something needs to be inserted through the nozzle opening. If that capability existed, it would be an easy stretch to add a magnifier so the user could guide a needle more precisely with less risk of damage. Then the thought of a heated needle.... Welcome to the perpetual motion machine of modification..... J
  19. I'm thinking open source anyway, so cost will be in the hands of the user. Creating the physical holder doesn't look too difficult, but some thought will have to be given to heat tolerance when the print core is being heated to clear a high temp filament. The electronics interface and heater power is really where it gets tricky for me. I agree, no need for all of the features of the standard firmware, I thought it might be easier to clone a controller, then use off the shelf firmware, but the function is basic enough that perhaps that is overkill. I'm a relative novice with GitHub. Is there source documentation for the printcore electrical interface and associated temperature control code? john
  20. I certainly see that benefit too. The nice thing about having a cleaning stand, especially since the UM3 (in my case) ships with two AA cores, is that even routine post print cleaning can be done on the stand. For multi printer operations where there are a lot of cores in play, this would have to make sense. Now, I know that Ultimaker and 3rd party makers like 3dSolex and gr5 know the electronics of the print core. I don't. That to me is the biggest unknown, managing that interface safely. How big a challenge is this piece? J
  21. Great workaround! I will check around to see what needle spec it would take to safely enter that nozzle. The comment on the rod bending prompted me to start a separate thread on a print core cleaning stand. I'm wondering if your technique could be incorporated into the design considerations for that device. Gotta love the sharing here! John
  22. Good morning everyone. I'd like your thoughts on the following: I've had to clear jams on occasion, and each time I wonder what I am doing to other parts of the printer during a hot pull. The thread from kman on the PVA mid print pull (excellent workaround BTW) prompted the same concern. Then it hit me: With removable print cores, why are we forcing all this stress on a high precision printer head supported by bendable rods? Why not have a robust stand that you can slide the print core into, properly supported so it can withstand a cold pull without damage, power it properly to a selectable temperature (or temp schedule) and then do the work there? Now, I realise this is going to have to be a smart stand. My initial thoughts would be arduino running some portion of the full Ultimaker firmware, but really just enough to control temperature. There would have to be a proper electronic interface to the print core, so the power supply would have to be managed. I looked around my shop and realised the hardware needs are not really that big a stretch. But first impressions in this business are sometimes just a rabbit hole. What do you think? Is this doable? Anyone up for a bit of collaboration to get it done? John
  23. This material has been mentioned a few times on this forum, some folks seem to get it to print without difficulty, but for others, it almost seems as if the attempt harms the printer. I am planning to run this job on a UM3 with a Hardcore 0.6 Everlast nozzle. The print is not complex, no serious overhangs, it's really just a cylinder with a central bore and some detail up the sides. It prints in under an hour with woodfill. Thanks in advance for sharing your experiences and advice! John
  24. Just bumping this thread to verify the nozzle setting, about to print some woodfill today.... Thanks! John
  25. Good morning. The E3d mod and fan mods have both been done to the UMO by others here, hopefully you'll hear shortly. I've only had to repair my UMO PWM control (transistor) and am still using the original fan. That said, you might find the following post starts you in the right direction. The board sends 19V to the fan, so not all 12V fans will work. As I understand it, even in parallel, you might need to manage the voltage down. Presuming for a second that the fans can handle the voltage, there is normally a pretty high threshold to start rotation, after which the setting can be dropped. Your post doesn't say whether you experimented with lowering the power from 91% to, say 50% once the fans were running. If they keep going and the speed lowers as requested, that would suggest that you have control of them and there is just startup to tweak. Good luck J
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