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Everything posted by dgsharp

  1. I just wanted to echo this. For a long time I had a worn isolator and I spent a lot of time looking at the wrong things. ABS was the only thing I could print. When I finally realized it and got a new isolator, it was a whole new machine.
  2. A more stable Z stage that doesn't bounce around so much. The current one is cantilevered out way too far, reducing print quality and compromising bed leveling. Auto bed leveling. Much less necessary with a beefier bed but still very handy. Feeder that doesn't jam so much. I designed the Hive76 Milled Bolt, a pinch-wheel with very positive grip. Once there was a filament jam with one of the printers with the filament spool hanging from the ceiling and the machine climbed right off the table. I'm sure there are lots of approaches that will result in a less finicky feeder than the UM2. All me
  3. I did one or two test prints at 20um early on and they turned out ugly, fuzzy, etc. I didn't think it was worth trying to improve it because trying to get that sort of resolution out of this type of machine is basically a waste of time: it takes forever and just isn't worth it for anything I've seen.
  4. As 3DMaker4U suggests, it all depends, especially based on the mechanical properties you need. That being said... In my experience typically PLA is capable of capturing finer details. It also prints with a more glossy finish, whereas ABS prints with more of a matte finish that can sort of blur fine details out a bit. The glossiness of PLA can also bring out more subtle flaws and artifacts though, like 'ringing' from acceleration.
  5. I found the same thing with NinjaFlex (I had to move the knurled pinchwheel onto the shaft further). Even with the snap-on part of Robert's feeder the filament still squishes through sometimes, so I have to watch the first 2 layers or so. If it fails I check things over, maybe add a touch of oil to the bowden (not very frequently), just check everything over. Cut off that section of filament if it gets really permanently kinked up at the feeder. Maybe pull the bowden out of the hotend and do a cold pull with PLA to clean out anything that might be getting held up in there. Usually I have to do
  6. Dirkels, one that frequently bugs me is that if I have a model that takes a long time to slice, and then I decide to switch the settings for Support Type or Platform Adhesion, I am forced to wait until the slicing is done before Cura will allow me to change settings. If I try and change these settings before it's done slicing, the dropdown combo box will not stay visible long enough for me to do anything. That gets pretty old. I often have to resort to something like scaling the object down to be very tiny (so it slices quickly), changing the settings, and then scaling back up. -Dave
  7. ALL RIGHT!!! Ok, I am tentatively saying this is solved. I installed a new bowden tube, new heater block and nozzle (the old ones had totally seized up solid and broke while trying to disassemble it to clean it), and straightened out the filament. I was able to print one of Illuminarti's cylinders completely. I had my finger dragging slightly on the end of the knurled wheel so that I would immediately feel any pops of under-extrusion, and there wasn't a single one. Beautiful! Now if I can just get it to stay that way! Thanks once again Illuminarti! -Dave
  8. I see. I've been using the latest firmware, and 20mm sounds about like what it's doing. Until I replaced my teflon piece today, 20mm retraction would be a "huge amount" and result in an immediate jam if allowed to cool that way. Now I realize that my teflon part was almost certainly the culprit of that particular symptom, allowing the large bump to form internally which then can't be effectively drawn back through the bowden or pushed through the extruder. The material I'm printing is silver PLA, slightly under-sized and in the past it has printed very well for me. I am down past the halfway
  9. Another status update: about 2-3 hours into my print I started getting really nasty under-extrusion again (speed 50mm/s, height 0.1mm, temp 230C). I slowed it down to 50% (25 mm/s) and let it run for several layers and the under-extrusion didn't stop (feeder stepper kept skipping steps). I did notice that it seemed to lose steps around one particular area that had several retractions, so I lowered my retraction speed from 35 to 25 and distance from 5.5 to 4.5. I then bumped the speed up to 75% (37.5mm/s) and let it go a few layers, and it still seemed good. I had to abort the print so I figu
  10. Finally an update: I've received my replacement teflon part, and now that I have the two side-by-side I can see just how bad my teflon part had become. I'm attaching a picture showing them both holding a short section of identical silver PLA: Despite the poor quality of my picture, and beyond just the obvious blackened tip of the old part, there is a very striking difference in how closely the parts fit around the filament. The new part actually holds onto the filament slightly here, due only to the slight bow in the filament. The old part is extremely loose, with lots of clearance between
  11. Thanks again for all the thoughts and PM. I took off the heated build plate and poked around and saw no signs of blackened wires or loose connections anywhere. It did look like at least one of the screws holding the black rubber piece that attaches the cable to the build plate was loose though. My current theory is that because that was a bit loose it allowed the solder joints on the back of the build plate to cycle and wiggle just enough that one of the solder joints failed. I opened it all up and the surface-mount connector came off, quite possibly due to my handling. One of the solder join
  12. Thanks for your thoughts, I will investigate them all as soon as I get a chance. As for the heated bed, it gives no error, it just never prints, or the advanced option to heat up the build platform isn't able to affect the temperature. No wires seem to be loose but I need to fully tear it apart to get a better look at things. My Bowden tube doesn't move at all, but I will be careful to try the directions you linked me to. Thanks again, will report back when I can.
  13. Well I put everything back together and left a print running at 210C. I came back after 9 hours or so (24h print) and halfway through one of the parts had popped off the build platform and it was printing air spaghetti. But spaghetti is better than caramelized PLA. I went to try re-printing it using the new raft option and.... my heated bed never got hot. (Presumably the heated bed died mid-print, causing one of the parts to let go of the glass.) So it seems like I have another issue in addition. Will update as I get a chance to uncover things. I haven't noticed any loose or discolored wires a
  14. I've been having more under-extrusion problems (UM2). The highest I've ever gotten on Illuminarti's cylinder test since trying it the first time was about 7, and I tried the other day and it was popping multiple times per loop, utter failure. Lately there has been some kind of gap somewhere causing filament to pile up, so that when I go to change material or when I do the "HAS-CAP" hot-end cleanout procedure it leaves a big nasty bump. I tore down the hot-end (except the extruder) and it's puzzling. I do the "HAS-CAP" procedure and I can see daylight through the nice round hole, but
  15. It could be something in the model itself. I've gotten wonky print files from people before and it turns out that the surface normals are goofy or there are unintentional internal faces and such. If you can get it into Blender or a similar program and really poke around to make sure everything is as you suspect, you may find your issue there. Usually when I have a strange disagreement like this between what I expect to print and what Cura produces, it comes down to the model. Might be worth checking if the settings don't fix it. If you'd like to upload the file, I'm sure someone here would be
  16. I was going to say you need to change the gcode flavor to reprap/marlin. I take it you did that as well? Or is that no longer a requirement? (That would be nice.)
  17. I disagree with the "any 3D supplier" comment. I got 3 spools of PLA and 1 spool of ABS from Makershed. They sold me my UM2 so I figured it'd be good. Two of the spools of PLA and the spool of ABS measure over 3mm, which you will commonly find listed as the absolute max recommended filament diameter. The ABS prints great regardless (it's a much softer material than PLA). The two oversized spools of PLA are very difficult to print, I have to print them at 20mm/s to keep from jamming up my machine with any consistency. Extremely frustrating to wake up after an all-night print at 25mm/s and the e
  18. I believe I'm using the latest stable UM2 firmware and pause (in the Tune menu) works just fine for me. I used it a few times today while printing some ABS -- there were some steep overhangs that left some very ugly areas curling up sharply, and I just paused after that layer, carefully trimmed the curled areas down with a scalpel, and resumed the print. I recall that Pause At Z wasn't working on the UM2 before (something about the relevant G-code not being properly implemented on the UM2). Anybody know if that works now? Manual pause is very handy though, still.
  19. I had one spool that was giving me issues after only about half the spool was done. I tried straightening it manually by bending it back on itself as I pulled it through some paper in my hand -- it worked but it was annoying. So the next time, I took a big pot and set it on a cookie sheet, and then uncoiled the rest of the spool onto the outside of the pot. It was coiled tightly enough that it held itself on there tightly all by itself. So I popped it in my (electric) oven at the lowest setting (I think like 170F? that would be like 77C) and left it for 20 minutes or so before pulling it out.
  20. It appears that cool head lift doesn't do an un-retraction after the last layer of a part. This appears to be the case whether there is just one part in the print, or if it's a multi-part print. This results in the next part having nearly non-existent extrusion until it has extruded enough filament to make up for the lack of un-retraction. I have had to use cool head lift to prevent organic shapes with fairly flat but curved tops from getting all gooey and melty. On a side note, why not do a cool head shift rather than lift? Whenever the extruder does a lift for me I get a long string or thre
  21. You're making me jealous Burki! I am dying to do dual extrusion. It's ultimately the only way to really do it right I think. I did a test today using TweakAtZ to print a solid tower, alternating the material flow percentage between 100% for 1mm, to a lower number (starting at 50% near the bottom and ending at 10% near the top), resulting in a number of 1mm-thick plates connected by fluffy, severely under-extruded support (I've been calling it "CUE support", for "Comically Under-Extruded" support). I found that after tearing away the clumps with a pair of pliers, the underside of the 30% se
  22. I have some parts that require supports, and I'm trying to find a reasonable solution. Normally it's fine to try and design such that you require no supports, use Cura's built-in supports, put in custom specific supports where necessary, or even chop the model up into pieces to be assembled later, etc. MeshMixer's supports can be extremely helpful, but don't do much on a fully overhanging surface. Ideally I would use a second extruder with a soluble support material (and hopefully we won't have to wait too much longer before this is an option! <nudge nudge>). But there's got to be someth
  23. I love my UM2 but definitely would not put it in the category of 'professional' machines. In my experience a professional machine just works, all the time, all of them have a second extruder for a support material, the software changes very infrequently... The results are reliable, but you pay for it. There are some things my UM2 can do that most pro machines can't, but they're just not the same thing.
  24. In case anyone is curious, here's how I found the X/Y resolution: - I created a sketch in FreeCAD showing a pie wedge with the radius of my sphere, as measured with calipers (the radius shown is in fact half the diameter I measured). - With calipers, measured the diameters of two concentric rings. In this case I believe they were the 2nd and 3rd rings, as the first one seems to be gobbled up by the backlash in the belts (25 microns of backlash ain't bad!), but it doesn't actually matter which rings they are as long as they are adjacent. - Added constraints to the sketch in FreeCAD showing e
  25. I used 20% infill for this, but this is not related to infill. I have a different model of a partial sphere I printed with 0 infill and it exhibits the same exact thing. I've confirmed that Cura's output resolution appears to be 10 microns. It uses 2 decimal places, but more importantly than that, the shortest distance between two moves along the X or Y axis is exactly 0.01 mm. We are almost undoubtedly seeing the effective X/Y resolution of the system, and it's right around 25 microns. Cura clearly isn't the limit if it is commanding moves of as small as 10 microns. So that leaves some
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