gr5

ULTIMAKER 2 SCHEMATIC and layout map - click "raw": https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_%28x1%29/Main%20Board%20V2.1.1.pdf

Measure the distance between waves as accurately as possible (measure many waves and divide by number of waves). Then measure the screw thread pitch as accurately as possible (how far does the Z axis move up or down with one full turn). Are they the exact same distance? probably. Maybe your Z screw is warped/tilted or bowed. What happens is the Z distance is moved farther than average for part of rotation and then less than average for the rest. This means some layers are slightly closer together and they get slightly too much plastic and it squirts out thicker so you get thicker walls. Then the Z axis moves faster than normal and you get thinner walls. It's very subtle on the Z screw but it shows up visible on layer thickness.

You are missing something. Do you have the PEEK part? It's kind of tannish brown. The bowden tube should go all the way to the white teflon part in this photo. Look at the head from the side versus a photograph. Showing a photograph from the side view of the nozzle/heater block/ head would be helpful.

Can you take a video showing the push action and rotate action? The knob should push and you should hear a click sound from the computer (a short beep). The screw holding the knob may be loose. It all comes apart starting with the cover at the bottom - don't try to remove any of the large panels - no need for that. There's assembly instructions in a large PDF somewhere that shows exactly how to put together a UM2.

ARCHE did you heat the nozzle to 150C minimum? Did you use a screwdriver to rotate the steel part? You need some tool that is skinny and fits into the holes. If you can't rotate the round steel nut then take the whole head apart. Remove the top plate - there's 2 screws - careful to squeeze while unscrewing it as there is a strong spring. Then you can remove the white teflon part (use a flat blade screwdriver and pry it out). THEN you can insert a tool ALL THE WAY THROUGH the holes on the top of the isolator nut. Now it's easier to rotate. If you break anything you can get spare parts at 3dsolex.com.

The left side always prints a little better due to the fan being on the left side of the UMO. Or did you mount a second fan?

Again - the only way to do this is with a plugin and use the M83 command to go to extruder relative mode. A plugin can easily subtract the 2 e values and output the difference (relative mode). I don't know why you would want to though.

All ultimakers have Marlin. They are all slightly different versions of Marlin but they all support the same gcodes. The older UMO printers don't support ultigcode mode but there are only 2 important differences. In "ultigcode" the machine retracts and unretracts with G10 and G11. In "ultigcode" mode E values are in cubic mm instead of linear mm. In ultigcode certain parameters are not sent to the printer (but they could be): bed temperature, nozzle temperature. Arduino is the hardware - it's a single chip computer. All Ultimakers use arduinos. It was a good choice 4 years ago but now they should move onto a cell phone based computer. The arduino is not very powerful. Not powerful enough to analyze video for example. Marlin only runs I believe on arduino processors. I could be wrong on that detail but it's probalby 99% arduino out in the real world if not 100%. You can write relative gcode but cura can't. See G91 and G90 in link in my previous post of gcodes. Marlin doesn't support conditionals (if statements) nor loops. The processor can't hold more than a few codes in memory and has no way to go backwards and re-read a file. So for example I have a gcode program that prints bracelets - they take about 6 minutes each. After each bracelet I have some gcodes the move the head back then down and then push the bracelet off the bed and then it starts over to print the next bracelet (there's a plow I add to my print head to keep the nozzle from melting the bracelet while pushing it off the bed). Anyway there's no "start over" gcode (well M41 but not implemented in Marlin). So I cut and pasted my code 50 times to make 50 bradelets, lol. There are no variables either. So you can't write much in gcode. But Cura does support plugins. They are very easy to write and modify even if you don't know python. Start with an existing plugin and look at the code and modify it to suit your needs. All the plugins are open source and python isn't compiled anyway so all the code is visible in anyone else's plugin. Or you can write gcode using excel or just a text editor. Excel is nice because you can put formulas in the cells - like if you want a circle.

Wow. Grounding issues. Unplug your laptop from your charger and anything else connected to house power (like speaker system amplifier - anything) I bet that fixes it. Plugging laptop to a keyboard or mouse is okay but unplug it from anything else like printers, ethernet, and so on. So then figure out which piece of equipment has grounding issues. Probably one of the plugs in your wall power is wired up backwards. You can determine this with a volt meter. Another alternative - plug the laptop, 3dprinter, and everything else that is powered (including ethernate router!) into the same power strip so that none of them has a ground signal that is at full AC power.

So this shaking of the motor can happen if the current is too high or if the current is too low. It can also happen if one of the 4 wires has a bad connection. Have you tried pronterface/printrun? (it's free and an easy gui to use): http://koti.kapsi.fi/~kliment/printrun/ After copying in pronterface, there is no installation - just run it. It is a nice gui to control your printer. connect a USB from your computer to your printer. Connect to the printer and then control the extruder. The extruder is not supposed to move unless the nozzle is hot so first you want to enable cold extrusions. You can do this by sending a gcode from pronterface: M302 When you power cycle the machine it will restore to normal operation. Use pronterface to try to debug the issue - I bet the extruder cable is damaged or pinched or one of the wires in one of the connectors is bad (at either end). Jiggle the wires while the extruder is turning. e.g. in pronterface tell the extruder to move very far: G1 E1000 (move 1 meter)

UMO tends to have more regular (perfect? consistent?) underextrusion than UM2.

I think you can change this on the control panel. If not you can certainly change this with gcodes - no need to recompile Marlin. http://reprap.org/wiki/G-code Look at: M92 Z160 M500

Yes. 275C. There is a setting in the marlin (marlin is the firmware in the UM2) called "HEATER_0_MAXTEMP" in Configuration.h. For UM2 printers it is usually 275C. The max temp you can set with the control knob on the printer is always 15C lower than MAXTEMP. If you go over MAXTEMP you get an error and nothing works until you power cycle. The UM2+ is a very new machine and evidently Ultimaker didn't adjust the PID settings (or the temp range where PID is enabled) in the firmware. This is unfortunate. The UM2+ has a 35W heater but the older machines have 20-25W heaters (nominally 25W). Hopefully someone will make improvements to either the PID values or maybe also the temp range where PID is enabled (I think it's within 20C of target temp?). A good "D" value should have prevented this I would think. Or maybe this will require custom code just for the 35W heaters. You could consider calibrating your PID values. There are instructions on forum if you use google to look for the details. Or just never start out at 260C (go to 250C first, then once it settles jump up to 260C).

In ultigcode mode the E values are *cubic* mm. This is so you can have 1 gcode file work with either 1.75mm filament or 2.85mm filament or 2.95mm filament and not have to reslice. In regular "rep rap" mode the E values are in mm. If your printer has Marlin you should know it has 2 modes: relative and absolute. If the extruder is in relative mode then the below 2 statements move the extruder 2mm. In absolute mode they move the extruder to the 1mm position (possibly moving backwards). G1 E1 G1 E1 I don't know if Cura supports "relative" mode extrusion but your printer should certainly support absolute mode. There is a gcode to switch between these 2 modes. More info on Marlin gcodes (and a few other firmwares such as sprinter) here: http://reprap.org/wiki/G-code I'm 80% sure cura can't output relative moves but one could easily write a plugin to do this. regarding steps/mm - this value is simply sent out as a gcode command at the start of the gcode file. Hovering over Cura parameters always tells you more details. There is a gcode to set steps/mm. This tells marlin (or other firmware) how many times to pulse a stepper motor to move 1mm. What kind of printer do you have and what kind of firmware is on the printer?

yes I've been in that situation. I've broken a few. I sell them for a reasonable price here: gr5.org/store/ The guy who wrote this guide only broke one temp sensor out of a 100 replacements. He also mentions the awl. he's more patient than I am. I was able to get a particularly difficult one out with a needle - getting it out just far enough to grab with the pliers. I have also drilled it out from the other end - you can feel a tiny tiny movement when you break through. It is subtle but also kind of obvious. Trust your feeling and don't drill any extra. Push out with paper clip. Oh. The guide - just read about how to get the sensor out: http://support.3dverkstan.se/article/62-installing-the-olsson-block-kit

You are underextruding on the top infill by quite a bit. The top few layers should be "solid" infill but you have 30% to 50% underextrusion. Usually this is caused by printing too fast or too cold. Is your infill speed different from the normal speed? I recommend you set all those optional speeds to zero so they default to the printing speed (infill speed, inner shell speed). 210C, 50mm/sec, .2mm layer height is too much. Try either 30mm/sec or increase temp to 240C (more below). but 210C and 30mm will give better quality than 50mm/sec at 240C. Also you may have shell messed up - it MUST be a multiple of nozzle size or it does weird things and you can get this problem shown. So if nozzle is .4mm shell should be .8mm I think in this case. If shell is .9mm then that would explain your issue. Here are my recommended top speeds for .2mm layers (twice as fast for .1mm layers): 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C The printer can do double these speeds but with huge difficulty and usually with a loss in part quality due to underextrusion. Different colors print best at quite different temperatures and due to imperfect temp sensors, some printers print 10C cool so use these values as an initial starting guideline and if you are still underextruding try raising the temp. But don't go over 240C with PLA.

A lot of people had this issue recently. They had to clean and sometimes take apart, clean and reassemble their Z stages. For almost everyone it was not so much the Z screw but the two Z shafts and bearings. All those little ball bearings get all jammed up. It turns out there should be no oil used - so take out the 2 vertical shafts (easily done from below) and remove the 2 bearings and clean everything and put it back together. Some people just put a 1kg weight on their bed and that was enough. WD40 is great at cleaning ball bearings. No oil should be needed with ball bearings as they don't slip - they roll.

If you do it for every filament - true. But takes me about 30 minutes to get 5 extra accurate speed/temp points for that graph. You can see the gaps between the infill lines if it is underextruding. Or you can hear the feeder skip back. So you just tweak the feedrate by 5% (5mm/sec) at a time until you find the max speed it can handle at a given temp. Then move on. For a 30mm cube I print out maybe the bottom 1/4 and then I'm done.

TFT is the name that Carl at 3dsolex made up to make it obscure what the material truly is. I don't know what it is other than it's some kind of teflon. It is *not* glass impregnated teflon. UM tried that and it made only a small improvement I suspect. No need to take the head apart to check the wattage - the markings are way off anyway. Instead measure the resistance - remove the wires from the block underneath the machine and measure with a multimeter and then wattage = 24 X 24 / resistance. The actual wattage is slightly lower (within about 1W I think) at temperature (200-260C).

DO NOT TAKE THE 6 PANELS APART. Dont' take even one panel off. You can fix anything without taking these apart. Instead remove the rear left metal cover. It is held on by 2 screws (or one screw on older models) and only takes a minute to remove. Then you have access to the feeder motor and can position it with one hand while screwing the screws in with the other hand.

This is very interesting @vinh. Do you have an infrared temperature sensor? I'd love to know what temperature you heated the pla to. I'm guessing around 52C. When you say "the filament becomes very flexible out of the oven", does it stay more flexible for an hour or does the effect only last for a minute? Does it have to be still warm to be flexible?

No. Sorry. But it's easy to characterize a filament. Print a cube with NO SHELL and 100% diagonal infill. Slice it at 100mm/sec so that 100%=100mm/sec and 300%=300mm/sec. Slice it at your most common layer height e.g. .1mm. Start printing. Adjust temp and speed and look carefully at gaps between each line - if there's a gap you are printing too fast (minor underextrusion). Keep notes. Within an hour you have a nice table of temperature versus speed. Print at half the max speeds. or at least significantly slower. Kind of like this:

I always use 100% flow so I think it's a little strange that you have to mess with that. I've messed with it many times but 100% works great for me. Anyway - I don't recommend you do anything different - just letting you know. You can get mad at me or your printer all you want - I'll be fine and it won't affect my responses in any bad way. It sounds like your main issue was with the ptfe coupler which is interesting. I sell the 3dsolex one - it's called TFT and is higher temp (255C) than the one that came with Um2. I think um2 has learned some tricks form 3dsolex - more than just the olsson block but also I think they may be shipping higher temp teflon soon (might be a few more months). I think overall in addition to having a bad teflon part you were just pushing the printer too close to the limit. I know you said you printed at slower speeds but I'm concentrating on your grinding problem and it's confusing if possibly one of your 2 issues went away with the lower speeds but not the other so you ignored that. Anyway... lets concentrate on heater error. Some of the heaters that come with um2 - although they are supposed to be 25W some of them are as low as 18W. I sell 35W and 40W heaters if you want to get one of mine. Or you can remove the heater error from the firmware. Also you may have a bad version of the firmware - here is a history of heater error - it's easy to check your firmware version on the front panel of the printer: heater error (as opposed to error stopped - temp sensor) You get an error if the heater can't move a certain amount in a certain time while driving full power (when it is close to goal temp it typically runs well below full power): Firmware Version 14.09 - does not have the feature 14.12 oct 16, 2014 - feature introduced. 20C in 20 Seconds 14.12.1 dec 15, 2014 - from 20C to 10C (still in 20 seconds) 15.01 jan 14, 2015 - from 20 secs to 30 secs (now 10C in 30 seconds) It turns out when daid introduced this feature into marlin his printer had a larger wattage heater than the standard um2. So if you have version 14.12.* you should upgrade firmware. If you don't have 14.12.* I recommend you buy one of my heaters at gr5.org/store/

You got a crappy block from Ultimaker I suspect. You need to tap the threads of the olsson block so that the steel coupler screws on all the way without any force. I'll do it for free if you pay for postage ($2.60 each way). I can send you a mailer and you can drop it in your mail box. Contact me at thegr5store _at_ gmail.com. I know this was a problem because I can see that your teflon part is touching the steel coupler in the photo above and it shouldn't be. It's easy to destroy either of the 2 parts when screwing them together so don't use more than fingers only for tightening the threads. I also sell steel couplers that fit the block a little better - what happened is not so much that the olsson block you got was "bad" but that your steel coupler isn't fitting as well as when it was new and the tolerances are all too tight. I make sure everything is ever so slightly looser when I ship olsson blocks. I test every block I ship.

Since you have three unrelated problems (third issue being bottom layer skip backs) but think of them as the same problem and since the treatment for one problem doesn't fix the other 2 - I thought you should revisit the tension issue for the grinding issue and revisit speed/temp for the skip backs on layers other than the first layer. A photo of the pattern in the filament (like the one I posted) would help convince me that is not your issue. There you go again - retractions is unrelated to back stepping. It's related to grinding. The sooner you think of this as 3 separate issues, the sooner you can fix one or all of them. Although I agree that retractions is probably unrelated in your case - at least for these large interlocking parts.