gr5

UM Original or UM2? Please also update your location (say what country you are in) and your description (say what printers you have) in your profile settings. This is an easy problem to fix but depends on the printer.

Ha ha! It's definitely a brag post. :-P Which is fine! It's okay to brag in this topic! Here - I'll do it so you don't feel so bad :-P My daughter is a Mechanical Engineer and smart as hell, she has one more year of University and already a job offer to design jet engine parts paying very well. So there! lol! :eek: :-P

By the way most UM2 printers don't have this problem. Mine doesn't have this problem. But I think some steppers are slightly hotter than others. Just 5C hotter is probably all it takes.

Probably because the stepper motor is hotter on longer prints. Especially problematic on some of the newer UM2 printers and with lots of retraction and after 30 minutes of warmup by the stepper motor. One solution is to print ABS which doesn't melt at such a low temperature (or XT or "high temp PLA" or nylon). A better solution might be to just put a small desk fan behind your printer and have it blow into the feeder to cool the stepper. Or remove the cover in the back left corner (only 2 screws) and put a fan blowing onto that feeder stepper. Another simple solution is to lower the current to the feeder stepper. Stepper motors use the same amount of current when they are stopped as when they are moving. You can set the current to any axis with M907 gcode. Just insert this line towards the top of any gcode file. I'd put it after the homing code (G28 I think). Default current is 1250ma (1.25 Amps): M907 E1250 Try 1 amp (although your stepper may now start slipping a lot): M907 E1000 Also consider raising your nozzle temp - perhaps to 240C? wamer PLA means more like honey and less like toothpaste which means less force on the filament so less grinding.

I've printed nylon PA6 just fine at 260C on the UM2. With fans off. If I print at 240C I get layer adhesion issues but at 260C PA6 is very very strong. I've printed dozens of parts - most of them less than 70mm across. I did strength tests here (PA6 is very strong): http://umforum.ultimaker.com/index.php?/topic/7575-strength-of-different-filaments/ I got my PA6 from here: http://fbrc8.com/ I think ceramic is a bad material as I think melted plastics will mostly stick to it although you can try coating it with oil. I think machining PEET might be a better idea although doesn't that melt at similar temps? UM is working on an all metal hot end but it could take years for that to be available...

Here is a link to the configuration file for the version of Marlin that is for the heated bed kit: https://github.com/Ultimaker/Marlin/blob/Marlin_UM_HeatedBedUpgrade/Marlin/Configuration.h On line 176 you can clearly see the limit is 150C. I don't think it can really get that hot though without some added insulation or enclosing the print area. I typically print at 110C for ABS. It works well for me but it takes a long time to get from 100C to 110C.

Probably clogged nozzle. For example sometimes the filament gets stuck inside the head when you first load it (never once it starts extruding). It might get stuck on the edge of something in there. Or dust. Or cat hair or other stuff. Also if you let the nozzle sit at 240C or hotter for a long time without extruding the plastic in the nozzle tends to caramelize into brown gunk. You might have to burn it all out but I recommend trying the atomic method first if it's not extruding anymore: http://umforum.ultimaker.com/index.php?/topic/4118-blocked-nozzle/?p=33691

printrbot (I believe - maybe I'm wrong) and Ultimaker are open source. MB is closed source. As other's have said "if you can't open it, it isn't yours". You can open your UM without violating the warranty. And the plans and electronics are all published. Schematics? Published. Layout? Published. Inner layers of the circuit board and everything is published. And the slicer and firmware are open source. That's a big big deal. It's not officially supported to print through USB but it works. Mostly. There is tons of error correction going on so if you print long prints you can get occasional fatal failures where a digit is dropped and Z moves to 1mm instead of 10mm or whatever and wrecks your print. If you play around with different USB cables, different computers, different USB hubs (for a well powered connection) it usually isn't hard to get USB working dependably. Ideally though you should check the logs to see how many failures per second you are getting and not be satisfied until you can print a whole 2 seconds without any checksum errors. Doesn't simplyfy3D let you output to SD card? It's just so much more reliable! And if your computer reboots because of some obscure quicktime upgrade you don't lose your print.

Well at .06mm layer height you are extruding at half the speed as if printing at .1mm layer height so the feeder doesn't have to work so hard. So this sounds like underextrusion still. You could try printing at thicker layer but slower print speed to compensate and get the same volume of plastic. For example if you print layers 2.3 times thicker then try printing 2.3X slower.

Because you aren't afraid to build it, definitely get the UMO+. The quality is now the same. The advantage of the UM2 is that it is quieter (like a guitar or violin, wood makes a great sound board) and most people think it's prettier and it's got those lights. The quality of prints is the same. The build volume is only slightly larger on the UM2. Homing is also nicer on the UM2 but not a big factor either way (on the UMO it makes more of a mess on the nozzle tip when it starts a new print but I just pull it off with my fingers - I know I could burn myself but I haven't yet). More important, dual extrusion is available now for UMO but for UM2 it is "first quarter 2015" meaning, what, March? Plus it will probably be pricey and complicated and may take a while to fill all the orders and might have a few bugs to workout so maybe next summer is more reasonable? I don't know. If you break something on the UMO+ you will already know how to fix it! You won't worry so much about warranties if the fix is simple (and it usually is!). And other nice things - like you can get a different nozzle diameter (wonderful thing) for the UMO for 5 euros (includes shipping). For UM2 it's more like 35 (??) euros plus maybe another 30 euros shipping? I forget the price but you can find it on the website. But for the UM2 you can only get one nozzle hole diameter so then you need a machinist to modify it for you. In other words the parts are a little more compatible with other reprap like printers out there so there's more parts available from alternate suppliers. Lastly I don't know what the lead time is for UM2 but I heard it was down to 2 weeks. So don't let lead time be a strong factor in your decision. I could be wrong! Plus it's in stock for many resellers. There is a reseller in Germany but I forget the name of it. They will tell you if it is in stock and you get customer service from Ultimaker even though you buy through local reseller.

I'm glad you fixed it. The temp sensor is a PT100 which is a standard part. Someone even has links to order one somewhere on this forum. All PT100's have the same temperature curve so you just need one of the right size. The print head on the UM2 also has a tiny PT100 inside it.

read robert's guide: http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide

Can't you share the results *without* the video? Why wouldn't you be able to share the results?

I think Z axis is now in "software endstop" mode after the install. Meaning after homing it will only go to a certain height - something like 205mm? You can test this with pronterface.

@mevander my next thought is that your Z screw is messed up. I mean that has been a coninuing thought. That cylinder looks damn good though - I would expect a repeating vertical patern of horizontal stripes where the layers are too close followed by too far. Your plan of using an indicator is excellent. It doesn't have to be attached to the nozzle. Any part of the frame that can then touch the bed is fine. You want to do similar movements to your test part so if your part was .2mm layers than .2mm movements in Z. Repeat as long as possible. Maybe you should just post the gcode for a box that you've printed with bad top surface. Maybe it's the gcode. This is kind of stupid - but how thick is your top surface again? Maybe you didn't do enough? Did I already ask this? You want about 4-6 layers for a really good top surface so top/bottom thickness=.6 for .1mm layers or 1mm for .2mm layers is plenty. Each layer should get better than the last.

@mevander - that's one beautiful cylinder. I don't think I've yet printed one quite that good. First of all when you say it starts separating around 4mm, well by default the fan comes on slowly and by 5mm it is at 100% fan. The PID controller is supposed to keep the nozzle at the same temp the whole time but stil... Did you try printing the cube at half speed and at 240C? Maybe you should check your nozzle temp using this simple technique in this video:

@mevander - can you send me the gcode for that box you printed that had underextrusion on the top layer?

@mevander - sorry - it gets confusing when 3 people have posted in the last 3 days with similar but quite different issues and I'm too lazy to go back and read all your posts again. I feel like we ruled out underextrusion because you can print the cylinder just fine. That leaves Z axis. You said it was fine but - I think that on the top layer of your cube the Z must be moving too far. Really nothing else makes sense. The top is underextruded. The gcode is fine. You can print the cylinder fine so and your extruder is accurate (within 3%) so the onloy thing left is that the Z axis moved too far on the last few layers. This is a common issue on UMO but not common at all on UM2. I guess I'm kind of stumped. Is your Z screw twisted or bent? How did you do the Z movement test? I guess I would do the following: Get control of your Z axis again with bed and head at room temperature. Move Z axis off the surface of the glass by same amount as your part - or a little less. Then slip a stack of paper under the nozzle. Measure the thickness of 10 sheets of paper with a micrometer and divide by 10. Then move the Z axis by this amount many times and slide one sheet of paper under the nozzle each time. Feel the friction of the paper as it slides in each time. Are the Z movements consistent? Or are they variable? Repeat over a few mm (at least 20 sheets of paper. 30 sheets might be better). I'm expecting the Z to occasionally move 2X as far as intended (and other times maybe 1/2 as far as intended). If this test passes then I want to go back to underextrusion and see a closeup photo of your test cylinder that you say printed fine.

Picture please. From Cura maybe. Click "Gallery" in top left corner of this page, then "upload" button. Then make a new post and click "my media" next to smile icon.

John please specify what country you live in and what machines you own in your profile settings.

I'm pretty sure there's only one version of the schematic for the UM2 at this point. Any changes to the board have been parts only I suspect - the layout likely hasn't changed.

Those holes are partly created by underextrusion which you can fix by printing a little hotter or a little slower (e.g. 50mm/sec .2mm layers 240C should be fine) or you can try tightening the screw on the feeder. My spring is compressed down to 11mm if that helps although I think that isn't helpful as the feeder design has changed a bit I think and it might not be the same spring. ALSO I agree that you have some X/Y error. It's caused by "backlash" also known as "play". Backlash can be caused by loose belts or very high friction. In the case of loose belts, the head never moves as far as the stepper commands it in either X, Y or both. In the case of high friction, the head also never moves as far as commanded because even though the belt is tight the head doesn't move that last .2mm because static friction holds it in place. So push the head around in X and Y. If you push with the side blocks you should be able to push the head with one finger on each side block. X and Y friction should be similar. Put some oil on all 6 of the rods in the gantry system. Any light oil will do. More likely though the problem is the belts are too loose. Start with the X and Y short belts. Push the motors down quite firmly. The longer belts are trickier to tighten. I recommend using the metal part of a clothes pin and using that to tighten the long belts. Google it. More info about the relationship of loose belts to print quality results here (posts #7 and #8 - look at picture in post 7 and read the text connected to that photo - you have to click on the photo first and then the phenomenon is explained better in post #8): http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=14396

Brim is easy to remove afterwards. It's a fantastic feature and I use it on 80% of my prints. It helps parts stick to the surface - especially if they have sharp (square) corners. Make sure you clean your blue tape with isopropyl alcohol. Blue painters tape comes with a waxy substance that keeps the tape from sticking to itself. isopropyl alcohol (just put it on a tissue or cotton and wipe for a few seconds) removes that. Other solvents might also work - not sure. But rubbing alcohol works great. Found anywhere bandages are sold:

For the record - how many polygons did you have when it barely sliced at .1 but not .09? That would be good to know to have an idea of the limit of polygons (very roughly).

The test cylinder MUST be done at 230C as it is meant to run at that temperature. Any other temperature invalidates the test. I've been doing some limited printing with nylon at 260C. My isolator still seems okay (I have the glass filled one). Maybe 10 or 20 hours at 260C total. I also like to keep it cooler (240C or colder) to avoid warping the isolator. A small chance, yes. Mostly the danger is scratching the bottom surface of the nozzle. You want that very smooth and flat. It's easy to file it flat again if you scratch it using emory cloth. So when you insert the needle the first time to it very gently until it's in the hole, then you can scrape the *side* of the needle in a circular motion against the *side* of the hole without being gentle. Also only insert the needle 10mm inside the hole so that you don't scratch the isolator (which is about 30mm from the nozzle tip). You have to do this while the nozzle is at 180C or warmer so that the PLA is soft. I recommend a cold pull immediately after.