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Also be aware that if you set your speed over 100% and some of the layers hit the "5 sec minimum layer time" or whatever your layer time is, then you will be overriding this minimum layer time. For example if you had it set for 5 seconds and you print at 200% then the quickest layers will be printed closer to 2.5 seconds and they might not have time to cool before the next layer is printed.

A little background on speed. The speed is called the "feed rate" which is not a 3d printing term but a generic CNC gcode term. The feedrate gcode is controlled with the letter "F". The limiting speed on the UM is mostly X and Y. Most moves do not include a Z component. So on normal extruding moves (not bottom layer, not limited by minimum layer time), the feedrate is set to whatever mm/sec you set in Cura. Once set, Cura doesn't mention feedrate in the gcode until it changes. When you do a Z move, the feedrate is specified because 100mm/sec in Z is too fast (on the UM1 anyway) and if you do extrude-only moves such as retraction, the feedrate is specified (but not ulti gcode mode) also because 100mm/sec in E axis (extruder) is much too fast. Now on the controller for UM1 and UM2, if you change the "speed" you are multiplying by a percentage. So by default is 100%. If your feedrate in Cura was say 60mm/sec then speed=100 is 60mm/sec. If you increase feedrate to 200% you will be printing at 120mm/sec. 10% will be 6mm/sec. If your non extruding moves were 150mm/sec and feedrate is 200% then the non-extruding moves will be at 300mm/sec. However... There is a max speed and max acceleration for all 4 axes. For example, typical XY max speed is 300mm/sec. If setting "speed" or FR (feedrate) to 200% goes over these max values then it will only increase up to the max speed. Changing the FR to 200% does not affect the max speeds or the accelerations. So printing at 200% will never print twice as fast. If you were printing slow enough then it will be almost twice as fast but never quite. Also Marlin continues to be very careful to never violate jerk or acceleration settings and always move in a straight line (linearly). So if the extruder only needs to move 1mm and the X axis is moving 200mm, the limiting speed for the extruder will be set by the acceleration, max speed, etc of the X axis. Changing flow in effect changes the steps/mm of the extruder (without violating the existing max speed of the extruder). Basically Marlin implements all this just the way one would want it to work.

It's in the painting section. Painters use it especially on corners and edges to keep paint off of something. The blue tape is what most people use. Green (frog tape) works okay also I have heard. I also hear white masking tape works but that has a different kind of glue that might be more difficult to clean off the glass. Get as wide as you can. I use 75mm wide. Illuminarti found some 150mm wide! Wide is good for 2 reasons: 1) If lifting on a tiny surface, you want as wide as possible tape as possible to hold down. Skinny tape lifts too easily. 2) It takes less time to apply the tape carefully (getting the edge of one tape perfect with the edge of the next tape). MOST IMPORTANT, clean the blue tape with isopropyl alcohol before printing on it. This removes waxy surface. This alcohol can be found wherever bandages are sold:

I just read it. Nice. Although people can make 2 perpendicular lines using a square. Anyway - thanks for doing this!

Okay I just looked at your picture, nico and calibrated it using both the nozzle outer diameter of 6mm and opening of 8mm. I get that your nozzle hole is smaller than mine by 30% to 60% area. Doing identical comparison, metal to metal, I get that my hole diameter is .49mm and yours .38mm (that's where the edge curves inward into the hole). Comparing the blue filament in my hole - blue edge to edge - comparing that to your nozzle hold metal to metal I get that my hole diameter is .43mm. Either way my nozzle hole seems larger than yours by a significant amount (at least 30%). This technique of course could use some accuracy improvement! It's hard to say exactly where the edge of the hole is. I tried the same technique for both photos, but differences in lighting can change where it looks like the edge is. That photo that showed light coming through the nozzle hole would be the most accurate if one could photograph a ruler at the exact same distance (preferably in the same photo!). I measured 4 different directions (horizontal, vertical and 2 diagonals). If I use the SMALLEST of my 4 "metal to metal" measurements of my nozzle hole, and the LARGEST of the 4 "metal to metal" openings of your nozzle hole I still get .46mm for my nozzle versus .40mm for your nozzle. Which in area is still 30% difference.

Absolutely not. You are confusing UM with Makerbot. They are just a very small company and are very busy. This is something they are looking into seriously. Part of the problem is that it's not clear what the problem is or if there is a problem. I know they are redesigning the extruder but in the end they might decide the current design is better (I doubt it). UM is the kind of company that would offer free extruder upgrades to all owners of the UM2 even though they have no legal obligation to do so. But only if they find there is a serious problem with it. It may be the solution has nothing to do with the extruder. I have 5 good theories for what Nicolinux's problem is. Also it's not clear if 1% of the people out there have extrusion problems or 60%.

It's pretty easy to disassemble - only 4 screws - but then the motor wants to fall so I guess there is a 5th screw to remove the motor cover access. The spring is too strong so everyone uses the loosest setting. I think UM will come out with a weaker spring so there is more control but right now the loosest setting for the extruder is about right. The coolest thing about the UM2 extruder is that the firmware (and gcodes) can control the current. So you can set the current to a threshold below where the extruder grinds the filament. So what happens is if you have too high a pressure, the extruder skips steps backwards instead of grinding the filament. On the downside - it's weaker than the UM extruder. And some people are blaming it for underextrusion issues (completely convinced!) but to me it's not clear where these people's underextrusion issues are coming from so the jury is still out. Also it is made of ABS and gets worn slowly over weeks of use and very tiny pieces of ABS can get into the nozzle which can also cause problems. Maybe. No one knows.

You need to post a video I think.

I disagree! that photo is better than mine. Please: 1) Turn UM2 off, put it on it's "back". 2) Slide nozzle to the top (the front). 3) Tape a caliper to the print head so it is as close as possible to the nozzle. 4) Photograph the same thing but with both ruler and nozzle in the same photo.

Well it's designed to be printed on blue tape and you need to clean the blue tape first with isopropyl alcohol. The blue tape comes with the UM2 but you will have to re-level Having said that you could experiment with other surfaces. Here are some notes. You don't want it *too* sticky: http://umforum.ultimaker.com/index.php?/topic/3404-printing-on-glass/ I would love a copy of the official "looping forever - push off with fan duct" version as I will be showing off a UM original and a UM 2 at a science expo in a few months and want to print bracelets continuously during the expo.

You misunderstand. As long as you use the version here: https://www.youmagine.com/designs/official-ultimaker-robot#!design-flag then you can sell it as long as you tell people where you got the original file for it. Just don't use the version from thingiverse. Siert is also a founder of Ultimaker.

I think you should try kisslicer. It's free - it has a nice GUI - it's not too bad. Just make sure you set *ALL* the nozzle widths and line widths everywhere to .4mm. I'm pretty sure you can print the bottom 1/6 with more infill. I'm not certain. Oh - netfabb should be able to do that also. In cura you could slice it twice - slice it each way, then simply cut and paste. The layer numbers are right there in the gcode comments - there's no reason you can't simply cut and paste - no other editing needed - oh wait you need to reset the extrusion in between where the files are sliced together with a G92 - see this: http://reprap.org/wiki/G-code#G92:_Set_Position Something like G92 E853.17234 Which tells the UM that the extruder (e axis) is currently at position 853.17234. - George

No matter how simple you think your explanation is, we need to see it visually. So please post a picture. It sounds like your slicer got confused where it got thin. Cura really is a pretty good slicer and most people here can help you with any settings that aren't working for you. Cell phones take fantastic photos these days and most can get very close for some good macro photography. Waiting for head to hit 30C is not what robert meant. He meant wait for the *bed* to hit 30C.

Ultimaker will be selling one... soon. Not sure when. Some time in 2014 I suspect.

Roald - you need to invest in a multimeter so you can measure the voltage across the coil and then if that looks good so you can measure the resistance across the contacts. Without a multimeter this is going to be tough to diagnose.

Shurik - you forgot to mention this. From your post:

Strange. Well add a drop of light petroleum oil to the axis and push it back and forth over the oil. See if that helps. I think the linear bearing isn't a typical "linear bearing" in that it needs to allow the shaft to rotate also. So it is simply a copper sleeve (I think - maybe - not sure). If you loosen the 4 screws on top several turns you can probably slide the bearing out and slide it along by itself. Maybe it's being twisted because maybe your UM2 is crooked (was dropped during shipment) and the two rods going through the head aren't square anymore. But that would affect the X also. More likely something with the belts? All the rods can be (and should occasionally be) oiled. But not the Z screw - that should have grease only. Any light petroleum oil is fine preferably with no additives (WD40 has additives).

In other words, maybe JHinkle should do this. UM is open source - people can download the plans and make it and UM gets zero money. This is a nice thing to the community. In return the community (me?) helps out and contributes in return. Some of the designs basically came from the community and not UM (for example the current extruder design on UM Original). Makerbot on the other hand is just out to make money (just my opinion of course) and so I would expect it's harder to get people to help out for free. Because UM is so nice, and because you will be helping other people - maybe you could post it on their wiki?

From the video it looks like you have 2 issues: 1) Levelling was slightly low so it's not sticking to the blue tape and instead sticking to the print head. 2) Axes are slipping. #1 you can fix by just loosening the 4 screws a 1/4 turn. #2 is trickier. You could mark all 12 pulleys and rods with a sharpie to see which are slipping. Or you could just tighten the hell out of them. Or do both. You should tighten the set screws so much that the steel shaft of the screwdriver is twisting. Alternatively you can replace the black set screws with the shiny ones that came seperate. The shiny ones have a sharper point and work better although I'm still using the black ones just fine. Make sure you get all 6 on each axis - the two hardest to get to on the short belt are the most likely to be slipping. Also add a drop of light oil to the 6 rods and also the 2 vertical Z rods and make sure you greased the Z screw with the green stuff. Light oil should be mineral oil with as few additives as possible (WD40 has some cleaning additives that should be avoided but it's probably okay). More on how I level: leveling here is defined as setting the Z height and also leveling. It's one procedure that does both at once. Optionally heat up the nozzle to 180C because a cold nozzle shrinks and you will be setting the bed to the wrong height. Make sure tip of nozzle doesn't have any plastic on it or you may level to the wrong height. I usually prefer to level with a cold nozzle but if you want extra accuracy then use hot nozzle. If you have a heated bed that should also be warm for the same reason. Home the z axis only. If you must home all 3 then you need to disable the steppers once it's done so you can move the print head by hand. Move the head as close as possible to each of the 4 screws in turn. Once at a screw tighten the screw and then slip a piece of paper between the nozzle and the print bed. Make sure the paper slides very freeley. Then loosen the screw until the paper gets slightly stuck. You want the paper to easily be able to slide in and out under the nozzle with one hand pushing the paper. If the paper gets stuck it's probably too tight under there. While levelling try rocking the bed across both opposite diagonals to see if one of the screws isn't touching the bed and to see if the bed is "hung up" or stuck on the threads of a screw instead of on the screw head. Repeat this procedure for the other 3 screws. Then go back to the first screw and repeat on all 4 screws again. Then repeat on all 4 screws again. Then again. It may take you 20 minutes to do this the first time but the second time you do this it should take much less time because you are both better at it, faster at it, and because there isn't much to adjust the second time. Note that the act of putting the screwdriver in the head can apply weight to the bed and change the height. You have to be careful to put as little weight as possible when testing with the paper. If you leveled with a cold nozzle you are done. If you leveled with a hot nozzle you should then loosen the 4 screws 1/8 of a turn to compensate for the thickness of the paper. Once done leveling rotate the z screw by hand to keep the nozzle off your bed. This makes it less likely to damage your bed surface and gives the nozzle room to leak. On a new ultimaker repeat this procedure before every print (at least every hour) because the print bed can move/droop like a new guitar string. After many months the droop slows down.

Also try pushing the head around with the power off. See if there is more resistance or noise in the Y direction.

UM Original or UM2? Can you post a video? I think you have to post it somewhere else and link to it maybe. Or gry clicking "gallery" in top left corner of this page and see if you can upload it there and then make a post and click "my media" next to smiley face.

Okay - new theory: Your nozzle diameter is smaller than mine. I just measured it with a camera as you can see. I used photoshop which measures sub pixels nicely at any angle. I measured 10mm for calibration and then measured the nozzle diameter vertically, horizontally, and both diagonals and averaged the 4 measurements. If I measure to the edge of the light blue I get: 0.43mm If I measure to where it looks like the metal starts I get 0.49mm. I started with a cold nozzle with a little filament hanging down and broke off the filament flush with my fingernail.

Yay!! I just read all these notes at once progressing through your 8 hours in my 2 minutes. At each step I thought the same thoughts as other people and then you replied with why their advice was wrong and I saw that you were right but eventually you got to the root problem (the print head). I think that most people were just lucky and their print head was square when assembled. It's been so long since I assembled mine I really don't remember having squaring issues.

Once in translate mode, don't scale the part. Only rotate it. The rotation handles are different. And then (again help in illuminarti's article) there are tick marks - if you hover over those you can rotat exactly 90.0 degrees instead of 89.7 or whatever.

Yes - I can barely print that fast. Without severe underextrusion. But that's right at the limit so quality is better at slower speeds. - George