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JohnInOttawa

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Everything posted by JohnInOttawa

  1. That's a great article Steve. Thank you. The benefits of the weight savings are incredible and the part looks nothing like I would imagine, so under the heading of 'thinking outside the box', this approach is game changing. Not only is there savings in building the part itself, but there is huge potential to save fuel, reduce emissions and, conversely, make parts much, much stronger than they are today for an equivalent weight. And guys like me are very partial to strong parts ? What follows is largely beyond the scope of the original discussion, but I see it as an inevitable crossroads as we refine these kinds or parts. One of the wild cards we seem to struggle with still is how to handle abuse cases in storage, handling, installation and in-service damage. We have an industry that grew up on over-built, over-engineered parts. An unintended benefit of some (not all) of these components is that they could withstand (often undocumented) conditions outside of the original design scope without exhibiting damage. (I need to be careful here as not all critical damage is visible and we know that big doesn't always equate to strong). Clearly there is limited excess material here by design. The 'armour effect' (my term) of redundant material is largely gone. We as an industry will need to adapt processes, procedures and reporting methods to safely use parts that have traditionally been seen as 'rough service' and assumed to be tough in all aspects, but now can be much more easily, critically impaired before installation. In terms of in-service threats - Using the context of aerospace operations, as a fellow involved in winter operations for much of my career, the first thing I look at when I see a part like this (or the 777 folding wing tip) is, how will this part withstand water and de-icing fluid ingress, freezing or, in the case of anti-icing fluids, high pressure rehydration ? While weight savings comes from material reduction, that means more holes or porous structures,. Some will be benign, others may introduce new vulnerabilities or stress points when a contaminant freezes or expands in rehydration. So a thought for the future - How does an engineer using this new capability train the generator to take a defensive approach with regard to handling or in-service abuse? Thanks again for expanding the knowledge base here. Always a worthy read. John
  2. Like many here, I've looked into what it would take to convert a printcore to accept a replacement nozzle. I came to the conclusion that the 3DSolex implementation is, at present, the most logical implementation of any such approach and the downstream running costs make it far more cost effective to purchase than the time it would take me to hack a lesser solution. From what I can see, there are a number of critical tradeoffs made in the design of the UM printcore. Weight is a serious constraint on that print head, so building swappability into an original design, for the few who would actually use that feature, may have negatively impacted functionality for everyone else. Then there would have been the inevitable support channel as that is a part that takes the brunt of abuse. Do I wish it were a less expensive part? Certainly. Would it have been great to have nozzle changeout incorporated? Yes! Is there an opportunity for someone to set up a used/damaged print core refurbishment centre? Maybe. In the mean time, 3Dsolex saw an opportunity to fill that void and they (and the agent I deal with) provide excellent support for it. I have two hardcores and a suite of nozzles for normal, fine and abrasive materials. Each one can be programmed for either AA or BB. I presume CC though I haven't tried it. The purchase has already paid for itself. They aren't perfect, you can still clog them and changing nozzles has to be done with great care to avoid breaking the very fragile components, but it's a viable option. I hope this is of some use. Just for clarity, I don't work for anyone who builds or markets ultimaker or 3dSolex parts ? John
  3. I'm not sure if this will help you, but I have a UM3 and, in preparation for printing nylon/CF I just ordered the Bondtech DDG upgrade kit. I believe the stock extruders' filament feed gears will wear at an accelerated rate with abrasive filaments. I've also read that the Bondtech feeders improve standard filament feed rates and reliability. I ordered mine from the gr5store. I see you are in the US, you might want to contact them. I've ordered from them a few times, a hardcore, everlast nozzles, bowden tubes, as well as the feeders. I've always been happy with the knowledge level, support and pricing. Disclaimer, I don't work for them, I'm not even in the same country. Here's a link. gr5 posts here as well. https://thegr5store.com/store/ Good luck! John
  4. Well, three things related to this that would help me: 1) the ability to print three materials simultaneously, specifically to support two model materials plus support like breakaway or PVA. If the third nozzle was just for support, perhaps it would not need to be as feature rich as primary print heads/cores. 2) The ability to lay down continuous reinforcement in a manner similar to markforged, but of course respecting the boundaries of their patent. 3) From the beginning of the print core concept I have wondered about the potential to have a completely different process use a print core station - something like a laser engraver or a light duty mill to improve surface finish or dimensional tolerance. Hey, a man can dream, can't he? ? John
  5. Thank you for sharing this information. This is a really great innovation. Given how easily UMO works with this system, I can see that printer will be with us for many more years to come, and that is a good thing!! Cheers John
  6. That's an interesting innovation. I was just starting to wonder what I should do with my UMO. This might answer that question. I tried to figure out how the support arms are configured. I get that there is yarn strung between the holders on either side, but can't quite see how that is incorporated. I presume the print is paused, the yarn strung flat, then the print resumes and the yarn is just buried in the filament, but when I see the pictures, it looks like the yarn is under tension downward. is the whole thing strung like a raquet, then lowered to create that tension before printing resumes? Thanks! John
  7. Same here, colorfabb with a 0.6 (hardcore). no issues with clogging, and I went to 0.1 layers. As an aside, I found this material printed with almost invisible print lines, but as I was going to apply finish, I sanded it anyway, and sanding worked as expected for a softwood like pine. I did have to pay attention to infill pattern, wall thickness and print temperature, I was printing cylindrical items with a vertical hole for a lamp wiring shaft, and my first attempt had a weak layer band that fractured almost in a crystalline pattern around the narrowest portion of the print. Cura layer view was helpful in seeing what was going on, I had managed for a few layers in the fracture zone to create just wall layers that did not divide evenly by the line width and didn't really give enough time for the layer to cool. This area did declare itself visually with a darker band in the material, looked like wood that had been burned by a router bit. By increasing that zone just a little the band disappeared and a test to destruction more than met my strength requirements. I hope this helps! John
  8. Let's try this approach: 1) please identify which slicer you are using - if it's Cura, then you're in the right place. If it's not, and this is not an Ultimaker printer (looks like the Tevo is a prusa style) then you might be frustrated at suggestions here that don't make sense for you. 2) I would try a different file of the same height but using less material so you can get past the shift point sooner - a vertical bar 2.5cm x 2.5 cm or whatever would be stable - just to see if this issue tracks with height, or time. If you get the same issue at the same height, again, I would think mechanical aspect. 3) Assuming you use Cura for a moment, I would sink the model in Cura to 25 or so layers below the problem area and print just that part of the model, to see if the shift occurs at the same place in the model regardless of how many layers have been printed to that point. If the shift happens anyway. then you can start to zero in on other things and you won't have to wait so long to see the problem and test a potential solution. I did for a time have a prusa style printer, which also experienced layer shifting at a specific height. In that case, it was indeed dirt on one of the Z screws that caused an asymmetry in the gantry, when I put a bubble level on the table it was level but the gantry no longer was. Not saying it's your case, but when things like this take place, it's among the easiest things to fix. John
  9. Not a printer I am familiar with, however if the problem is always at exactly the same height, regardless of how long it took to get there (i.e. narrow, low infill jobs get the same problem at the same height as large, high infill ones), then I would look at a mechanical problem instead of Gcode. Mechanical problems are not all broken things, it can be as simple as dirt in the Z axis leadscrew that causes more friction and missed steps. This is pretty common, especially in printers where the bulk of jobs stop at about the same spot, so debris gets pushed to the same level and congeals with the lubricant. Since you indicate that this all started when you recently decided to print bigger things, I'd start there, remember that most leadscrews are multi-threaded, so you may have three groove lines to inspect and clean per leadscrew. John
  10. This topic raises another aspect - I see more folks referencing IR temperature when assessing component health. While IR is an excellent method for non-contact temperature reading, the ease of use of current instruments belies the difficulty in getting a true value. We use calibrated IR handheld 'thermometers' and imagers in research settings and I've used them to assess stepper temperatures as well, on my UMO, during a long print. Depending on where the sensor is aimed, the surface texture and IR reflectivity and nearby heat sources, a handheld, single-point reporting IR thermometer can under, or over-report temperature. Over reporting tends to happen on surfaces with pits and valleys that create temperature wells, whereas under reporting is a function of surface material, specularity of the surface and surrounding sources. Error can make up more than 90% of the value that reaches the sensor. An imager is similarly affected, but tends to have adjustments for focus, emissivity, background temperature and transmissivity of the airmass (which can be a factor in a hot space like an enclosed printer) and reports thousands of points, so it's easier to see what is going on and correct for it. The other thing to keep in mind with IR reading is that it's solely a function of surface radiation. If there is any form of airflow over the surface or between the surface and the sensor, (like print fans tend to produce), it's going to divide the reading from reality. I've been meaning to post some shots of reading effects on steppers and heated beds. I was hoping to also get some images of a print in progress to show relative layer temperatures, but I will need some form of time travel to get the rest of my stuff done as it is.... John
  11. This looks to me like coasting - you're not extruding in the gaps but you'll lay down oozing filament. Try it again with no coasting and see.... John
  12. I have a 0.3 and 0.25, on a UMO and a UM3 so not the same thing. But maybe this is related. Can you share what adjustment you made to feed rate? In my UMO, I had to almost cut it in half for the smaller nozzle. John
  13. Thank you. I asked if the fellow would provide some traceability on the printer, that seems to be the end of the discussion. Maybe the community would consider forming a list of missing and suspect machines. Probably wasn't needed before, but as you fellows slowly take over the world, there is obviously a secondary market starting..... Thoughts? -John
  14. Hello everyone. Strange question of the day. A fellow has reached out to me, knowing that I have an Ultimaker 3, asking if I would like to buy his, new in the box, everything included, never been used, Ultimaker 3 for a too good to be true price. No receipt available, but he tells me it has never been registered for a warranty. Hmmmmmmm. Now I don't want to go around accusing anyone, but neither do I want to buy stolen goods, if indeed that is what is going on here. I know that there are blacklists for some other hardware, is there some way for me to check the serial number of this unit and see if it's legitimate or 'other'? Thanks in advance! John
  15. 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!
  16. Well said. Looking forward to the next chapter of fractal land ? J
  17. 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
  18. 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
  19. That looks like AN225 number two taken in the Ukraine..... John
  20. 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
  21. 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
  22. Sorry I didn't add it earlier, was soaking out the PVA. Post is updated with the print pic. Thanks again John
  23. 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
  24. 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
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