chrisw

Thanks @Labern. The Pt100 could definitely explain the 10C heat reading differences. I have a spare here, so I'll try mixing and matching to see if I have a similar pair. If not then I'll go to GR5 Regarding the feeder, maybe the bowden tubes are different. I'll try swapping those and see if the chirps follow the same tube to it's new home.

One of my systems is 1.5 years old, the other is .5. The settings and hardware are all the same to the best of my knowledge, but they act different from each other in a couple of ways. Both systems use: Robert feeder, Olsson Block with .6 nozzle, GR5's 35W heater, and the Ultitop cover/door. Difference #1: The newer UM2 shows approx 10C less nozzle temp in the control panel to get the same results from the same materials. This 10C difference has been the same for the stock heaters and the upgrades. It's not a big deal, but if it's possible to make them read the same it'd be nice. Difference #2: The feeder motor on the newer machine seems to "chirp" or skip a step as soon as there's any strain being put on it. However the feeder motor on my older machine seems to chug right along, pushing filament through stronger, only skipping a step if I'm pushing it hard. Could there be anything making these two feeder motors behave differently? These aren't really issues, because both systems are providing great print results. Just a couple questions I've been wondering about for a while.

Thanks for the tip on that feature. I have S3D and didn't realize it could do that. So of course today I went and experimented with that option. It opens a whole can of worms, and so far my results have not been better than the parked-head style of retraction. Chris

This is the fantastic part FBRC8 sent:

I was finally able to disassemble my newer UM2 and install the new Z-bearings that FBRC8 sent. These new Misumi bearings are much better than the originals. My non-exact measure of excellence for these bearings: I'd hold one bearing horizontal in one hand, slide in a rod, and see how much I'd need to tilt the bearing to make the rod start sliding. The results were a few degrees for the original bearings, and I couldn't make the rod be still with the new bearings. It was like first time trying to ice skate... no matter what I tried, that rod would slide one way or the other. After installing these into my system, the new UM2 system was now printing better than my older UM2. So I did a tune-up on the old system, and both are performing very well now.

Overall Cura is fantastic, so TYVM Daid! Below is an idea I've had while watching prints. Using PETG I've noticed ooze flow continues, even during and after retractions have occurred. Retractions do slow down the flow of material, so it's good to use them. But if the head stays parked while waiting for the retracting to happen then small blobs of material form beneath the nozzle. Later those blobs cause more issues when the head runs back over them. If it's possible to have retractions occur while the head is moving to its next target, I think this could improve the printing process with certain ooze-prone materials.

Any ideas about what those devices may be that're mounted to brackets at the front of each UM2? edited to add: Ok, my own question answered. It's a camera that comes with their wifi kit https://www.3dprinteros.com/store/easybox-wifi/

A trick that helps with that: When you're in Layer View of Cura, hold the + or to navigate 1 layer at a time.

I've done around 500 hours worth of printing with PETG so far, and no cracked glass yet (finger crossed). Maybe the 90C bed temp could be a cause of cracks. 75C has worked well for me. Popping noises are heard for 20 minutes or more after printing ends, but it's only the part separating from the glass

@SandervG Thanks! The still image makes it difficult to see the origin of these fireworks, but even crazier than jumping during a pyro show, our parachutists are launching them from the formation. A video is the best way to show what's happening. The last person you see jumping out is wearing pyro brackets on both legs. Fireworks ignite at about 1:10 into the clip: I work with a team called Canopy Formation Specialitsts. We train jumpers to do demonstration jumps around the world. One year ago I bought my first printer (UM2) with the sole intention of using it to make test models for some prototype parts. The end goal was injection molding. At the time I didn't realize that fully functional, durable parts could really be manufactured at home.

In previous years our parachute team would use tape for fastening lights to our helmets. The tape job needed to be redone each time we had a night jump. It was a time consuming job and it was messy. This year I had the tools necessary to make snag-proof light mounts that could be quickly installed or removed. My two UM2's worked hard for a few days straight to make 32 of these mounts. Modelling was done in OnShape, PETG material from Intservo was used, with a .6 nozzle installed on an Olsson Block, and of course the |Robert| feeder was installed on both machines

Sorry for the long delay, but thank you everyone for the replies. I'm convinced the linear bearings were an issue. FBRC8 was great and shipped out replacements fast. [media=8839]This is a sample of the banding I was seeing[/media] Then I dismantled the rods and linear bearings and discovered a good bit of static friction needed to be overcome before the beaings would slide down the rods. Once the bearings were rolling they'd keep rolling pretty well, but getting them started took too much pressure I thought. So I soaked the bearings in parts-cleaning solution, let them dry completeley, bathed them in sewing machine oil, packed them with grease by filling the cylinders with grease and forcing the rods in from each side of the cylinder, and cleaned off the excess. Now only a little pressure was needed to start the bearings rolling. I reassembled the machine and printed some new parts, and the layers were much more even. I don't have any "after" shots with me and I'm overseas, but I'll shoot some when I get home in a couple weeks. Maybe grease is a bad choice long term because it may gum up and cause sticking again, but for short term things did improve. I'll install the new bearings when I get home and see how they perform. Chris

Since day 1, my second UM2 machine has had a sound when the bed is raised or lowered. It sounds just like there's sand all over the Z screw (However I tried cleaning the screw and haven't found any grit). If I raise the bed using the UM2 controls, then turn off the power, the bed will sink a little immediately, then it'll hang. If I push down on the bed it'll continue going down, but it makes the faint grinding noises at a few times during the descent. I believe these areas of drag are causing banding in all prints from this machine. Has anyone else experienced this problem? Any ideas for resolving it? So far I've cleaned and greased the screw and both rods, but the noise remains.

@frederiekpascal Why'd you have to make it look so good? Parts ordered from 3Dprinterstore

Usually I'm just a couple hours away from Pasadena, but for those dates I'll be working in Florida. Bummer!

Oh is that what N-Vent is? I would have bought some a while back if I knew it was PETG. Taulman kindof shot themselves in the foot by being cryptic about the actual material... they lost at least 1 sale to me as a result

I like these guys: http://intservo.com/

Update after months of use: MadeSolid's product works great, however it's pricey. So I was always looking for an equal peformer for a lower price. Well I found it. Esun3d makes some PETG that prints even better for me than MadeSolid's. Esun's is a bit more flexible after the print is completed (maybe more glycol in the mix?). That works for my projects, and Esun's is less than half the price of MadeSolid's. Score! Also the diameter of Esun's has been more consistent, always below 3.0mm, ususally right around 2.95 - 2.97. So it works better in a stock UM2 bowden tube. Chris

M300 generates a 1 second tone on my UMO. I tried putting this code into the print that is currently running on my UM2, but no sound was emitted yet. I put these lines in a few places.. one copy at the very beginning of the print, and 3 more at pause positions that should happen over the next few hours. We'll see if any of them sound M300 S300 P1500 M300 S600 P1500 Maybe a simple M300 with no parameters would have been a better initial attempt

One more thing I want on my UM3: A direct communication device (text or audio is fine) going straight to @GR5. That way if I ever have issues, I don't need to walk to my PC anymore. Problem solved in a few seconds. What do you think?

1) For the three bed level adjuster screws: A limiter to show where the end of tightening should be. This matters most for the back screw. If someone, like me when I first bought my UM2, is unaware of the heated bed's wire connection being sandwiched in between the bed and the supporting plate, the screw can be tightened enough to put pressure on that connection. Immediate effects: It makes the bed not level. Long term effects: it can cause the soldered joints to fail (that's what I think caused mine to break... I needed to re-solder those connections a few weeks ago). btw: I'm not in favor of having an auto-leveling bed, if it's anything like the Lulzbot mini that stayed in my house for 3 days last week before I returned it. That bed would go through its slow leveling process at the start of every print. I only need to level my UM2 manually once every few weeks. After a few weeks that's gotta be hours saved compared to using an auto level script. 2) LCD screen and control switch relocated to the top front of the frame, It makes sense for ease of access, and it should be fairly simple 3) An audible alarm function that can be sounded using G-code for times such as when the system Paused... so I can wake up and do whatever needs to be done, and at end of a print so I know to start the next one. Maybe this is doable somehow on the UM2 already? 4) Easily changeable nozzles, such as Olsson block style. 5) A feeder like |Robert|'s. Easily disengaged, open for cleaning without need for dis-assembly, and not known for grinding. All these requests are fairly minor btw. The UM2 is pretty awesome as-is. I tried a Lulzbot mini last week because I need a second printer, and after reading so many glowing reviews of the mini, I figured it would be a good backup. Overall it was well designed and easy to operate, but wow the print quality at medium to high speeds was poor. I got spoiled by my UM2's accuracy, So I shipped the mini back and ordered another UM2.

Yes, exactly. I made supports that print on the glass. It has a few lines and then small cylinders that poke up through the screw holes to align the holes pause the print. The center round shape is one of the supports. It's wide below the plate, then continues up through a small hole and becomes part of the structure above that plate, basically tacking the plate in place.

For about 5 years I've been manufacturing gloves that have cameras attached to them, specifically designed for use in skydiving. We keep the design as snag-proof as possible to avoid interference with the parachute system. Before I bought my UM2 I was limited to only supporting one type of camera, the GoPro (I was using injection molds, and the tooling was far too expensive for me to offer much variety). With my UM2 though, these days I'm only limited by my ability to design and time available to do it. A few camera mounts that I've released over the last several weeks: There was quite a steep learning curve for me to be able to make these parts reliably. Each model has at least one nut captured inside, and a SS plate embedded about 4mm off the floor to reinforce the mount holes. I was sure I must've broken my UM2 a couple times when the nozzle crashed into the steel plate because it was at a slightly wrong height. The print was toast each time that happened, but the printer didn't seem to care. It's still working great. Skydiving is a harsh environment, so I figured these count as evidence of real-world use for printed goods. Chris

Thanks for the tips! I've been playing around with various settings and code changes all day long. A few times it seemed like I had it working: The system would pause, the head would move to a corner and sit/wait. The long extrude would occur (either in place, or as the head was moving across the X or Y axis, depending on which line I'd written for that particular attempt). Then the head would rush to its resume position.. at the right spot in the print, head primed, all ready to go. I was all excited because I had this issue resolved, I was sure... Then a retraction would occur right before the printer starts writing. So no filament is extruded as the head dances around over its target. There is no line in the gcode telling the system to make that last retraction. It seems like I'm fighting the firmware. So I even tried using M207 and 208 to set the retract length to 0 near the end, before the rogue retract occurs, then manually set it back to 8 as the writing begins. That didn't work either. I haven't used your idea of running printer/pronterface yet. That's next on my list when I have time to blow on this Chris

Agreed. You'll get a whole lot of answers here about which is best. It's like asking what's the best ice cream flavor. I bounced around looking for something that suited my needs and my budget, and ended up using Onshape for most everything. It's fast, smooth, and doesn't crash like Alibre :-) Chris