gr5

The rear fan should be on whenever the heater is on. It is independently controlled from the 2 side fans. Seriously though - check the wires. Something probably just fell off in shipping. Look on the head first. But the bottom cover isn't a big deal to remove.

It's a robot army! Something is still a bit off with your cooling but this is much better. Next step: eliminate stringing: http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/ When I tried to print the perfect robot I used the "cut off object bottom" feature and printed only the robot head to save time. I printed 5 heads until I got it perfect. To get rid of stringing, lower the temp - maybe more than you have so far (try 180C) - and increase minimum layer time a little - maybe to 10 seconds. And keep it under 50mm/sec like you have been. If you can eliminate that stringing I will tell you the final secret to get the antennas perfect. It should help the arms too. By the way: How is your play/backlash? If you grab the nozzle (while cold!) and push it around, is it loose at all versus the rest of the head? Are the bearings loose? Are the belts loose?

consider taking a piece of sheet metal and drilling a 3mm hole in it. Then passing the entire reel of filament through the hole just to make sure there are no more bad spots.

It's a lot of work! The latest firmware has typically 3 changes done to it every week. So it really should be tested thoroughly. With maybe a dozen different prints and settings and such. There isn't a lot in the latest firmware that is necessary. Plus Marlin fixed a bug related to retraction speed which can cause major problems for people if they don't have max E set to 25mm/sec or so. Also Daid has his own tree. And he has the UM2 version of Marlin... I suggest you get your own. This works great. I'm using the version here which is probably only a month old (I think Daid's is a year old now): Just make yours here: http://marlinbuilder.robotfuzz.com/ It works great! And after getting the hex file you can use cura to upload it. If you don't like it you can go back to the Cura built-in version.

Definitely fans should be working after the first layer is done. This is usually controlled in Cura although you might have a loose wire. In Cura, go to "switch to full settings", then "advanced" tab and make sure "enable cooling fan" is checked. Also in expert settings make sure fan speed min and max is 100% and "fan on layer nubmer" should be 1. If this is all true then something is wrong with your UM2. I would take the (larger) bottom cover off and trace the cable. It may have come loose in shipping.

FYI - I rarely do this. I just thought maybe some oils from your fingers got on there. Keep in mind that kapton tape at 25C is not very sticky for PLA. There is a threshold where heated bed at 60C is no better than 25C but by the time you hit 70C it is very sticky and works great. Once the first layer is done you can even lower the temp back to 60C and it continues to stick very very well. Lower it too much however and the part might pop off due to the aluminum shrinking.

I'm really surprised that Daid's duct isn't as good as the original. Are you sure that was it? Or did you change some other things at the same time?

It would be relatively easy for me to double the wattage of my heater. But I don't use it very often so it's fine. I thought of that but then it will cool down slower also! And it won't heat up "the chamber" as much. I occasionally tape clear plastic on the 3 sides with a box on top to get a warmer chamber when using the bed.

There are some gcodes in cura on the start/end gcode tab. The "end" codes should include a Z+0.5 to move the head up away from your part, and an X,Y -20 and then a X,y to position 0 (home position). All of that should move the head up and away. I don't understand why those would make it onto the SD card but not into the file that the cura "print window" uses. It should be the same file and the same gcodes. Probably the "move away" has been removed from the gcode and is now run in Marlin after the gcode file is done. So you could put it back in by selecting "reprap" or whatever Daid just said (Daid wrote cura). Anyway I would stay away from usb printing. It's very flaky. Many people have seen it crash 8 hours into a 20 hour print. Plus there are screen savers, power savers on your computer, (windows update nailed me once!). Better to use the SD card. Also the serial path is slower and sometimes if you have thousands of tiny line segments, the USB can't keep up. For example when printing the "yoda" model or anything scanned.

My bed is very thick aluminum (too thick - takes 20 minutes to heat to 70C). I have one layer of kapton on top and then a layer of blue tape. I never thought about that - that the aluminum can suck down the heat a bit. Thanks for mentioning it as I will keep it in mind in the future. And again - that white robot was printed at room temp so the aluminum was around 70F (21C). Something seems a little strange. I'm wondering if your temp is a little high. Or maybe it's just the filament - I haven't used UM gray in a long time and I'm not sure if it prints better cooler. Is there a way you can calibrate the temperature of your aluminum print head? Maybe test at what temperature it boils water? If it boils water at 80C or 90C that would explain everything. Remember that Marlin will shut down the extruder at 170C so if you go lower than 180C be very careful it doesn't over shoot and go below 170C. That white robot was printed with "white unspooled" PLA from printbl.com at 190C, 20mm/sec, .1mm layers. But I've printed "almost as good" at 70mm/sec 210C .2mm layers. Or at least no issues with the arm rings. Also I have a stock UM fan and fan shroud. Fan at 100%. Hmm. 20mm/sec fan at 100% is going to be a hell of a lot of more cooling than normal. I rarely print at 20mm/sec. I'm usually not that patient and not picky about quality (usually).

I would put it near a wall (window okay) on a table which doesn't have to be much deeper than the UM2 - about 2 feet deep is enough. You want lots of room to the side of the UM2 and you want easy access to both the front and back. So putting it near the corner of a table where you can go around the table side and access the back would be good. But this isn't mandatory - you can rotate the UM2 instead. So I would put it on a surface that is okay to scratch. If you will be printing PLA it can be in any room except maybe the bedroom. It is quieter than a dishwasher, or maybe similar. But if you are printing ABS it will smell bad. Put it in a room with a window and away from kitchen and bedroom if possible. Near a computer is good as you will be transferring files back and forth with the flash memory card. Don't put it in a dusty environment like an unfinished garage or basement. The dust will stick to the PLA and cause clogs which will drive you to pull out all your hair. Keep it away from wood working equipment that creates wood dust. Mine is in a "play" room off the kitchen.

A strange idiom, "half decent". It means: pleasantly good. But not amazingly perfect.

Lol. Someone already posted on the forum yesterday who received one. So the van was successful. I was thinking if there are maybe 40 UM2's in that van then that van is worth less than its cargo.

It's confusing. So there should be a line or arrow or something on the bowden. What you do is read the menus carefully - first you say load filament or something and it feeds slow. Then when it hits the line on the bowden on the back of the machine you push the button again and it feeds very fast until an inch before the nozzle, then it feeds real slow again with low current and when filament starts coming out you hit the button a third time and it stops. Something like that.

Same thing happened to me. I fixed it with kapton tape. I see you already have the yellow kapton tape so it should be easy to cut a piece and place it over the melted part and fold it back on itself. Now it can touch the aluminum block if I want and no trouble although I also rotated the aluminum block so it doesn't touch the duct anymore. fyi kapton tape can handle something ridiculous - I think maybe 600C?

Sorry man. Next time it pops off try the sandpaper trick.

UM claims the UM2 is "more reliable" which is very believable as their electronics should be more reliable (and more). The Z height movement should be more stable and consistent allowing smaller stepping but the UM1 has amazing Z stepping ability. I think you are going to have to wait for an answer until after many people have done many tests. The quality of a stock UM1 is very high and personally I feel the biggest improvement in quality (fine details) would be with a smaller nozzle size which you can only do on the UM1 right now. Having said that, the UM2 is better in many ways even if resulting print quality is not much better.

Huge improvement!! Don't use the heated bed? lol. I have one but didn't use it for that nice quality UM robot you mentioned. I just printed on blue tape (on top of kapton just like yours). Didn't even clean it with alcohol because I don't have much of a problem with this particular shape and size (small and contact with bed is larger (or at least no smaller) than the rest of the print). And the one from Erik also was not printed on a heated bed. Well you could up the layer cool time from 7 seconds to 10 seconds although 5 is plenty for me. I think you are at least partly right about the softness. Could it be moving it due to warping? How is your fan duct different from the standard one anyway? The one you linked to should be identical to the stock one in shape. I still use my stock fan shroud. Well the UM2 has a fan on each side. Maybe you should go with that if you plan to use a HB.

I didn't post earlier because I thought it was clear but what happened (obviously I think) is that the heater block got so hot it melted/softened the PEEK part (that brownish part) which shouldn't happen until way over 250C. Probably around 300C. The only way this can happen is if the thermocouple is still reading a valid-looking temperature, but the wrong temperature (reading low) which means the heater will keep heating to try to get the aluminum block up to temperature but it never gets there according to the thermocouple. So it's very important to figure out why the thermocouple is reading the wrong value and to calibrate it several times and test it before printing. For example a quick test is to set the temp to 95C and make sure no water boils on the aluminum block. The fault could be in the thermocouple or the board that translates the thermocouple into a voltage or in any of the cabling. Or even possibly in the board under the UM.

https://github.com/Ultimaker/UltimakerOriginal/tree/master/1114_Build_Platform_Acryllic The pdf doesn't have hole dimensions and I wouldn't trust reading the dimensions off the image. But the STEP file will have all that. I didn't bother adding slotted holes - insted I just blind drilled from the bottom and took the existing screws out of the bed and put them in pointing up from the bottom. It works pretty well.

It looks like the bottom of your part is a "shell". Maybe you could just send Daid the bottom 1mm of the part somehow. The bizarre thing is the skirt seems to be both inside and outside the part!

Here are some UMs being shipped - I presume this was taken yesterday. According to the photo EXIF data it was taken yesterday (Monday) in Europe at 4:30pm. I guess they had to ask for another truck! http://ultimaker.ipbhost.com/uploads/gallery/album_7/gallery_423_7_141670.jpg

I looked at your settings again and they appear to be what I would recommend for a high quality print (other than that 1.3). Another possibility is loose belts. My belts are looser than the ones I saw on all the UMs at MakerFaire, but obviously not "too loose" as my printer prints quite well. Have you watched and listened to this video?: www.youtube.com/watch?v=grHmmmSoOfc I tightened my belts the suggested way - by loosening those nuts shown in the video. It only tightens slightly but it was enough. The short belts may be more likely to be a problem and also easier to fix. Please only change one thing at a time so we know if it was the 1.3 issue or something else (for future people who have similar issues).

Try adding brim and also clean the kapton tape before printing.

Possibly the 1.3 wall (aka shell) thickness could be the problem. You should set this to 1.2. This should always be an integral multiple of your nozzle diameter. So what Cura is probably doing is doing the 2 inner wall passes at .4mm each and then a .5mm outer pass which means it isn't touching the inner walls very well and is overextruding by 25% (.5/.4) to make up the full .5mm with a .4mm nozzle. This causes drooping. The "good" side probably got a little more cooling - or perhaps the fan air didn't push down on the filament strings as hard? I could be wrong about this but this might explain it all. Also are you sure this is gray PLA from UM? It looks very blue in the pictures :smile: