gr5

RED ARROWS Okay. Now first of all, please post pictures on this forum. Will your picture links still work a few years from now? Probably not. To post pictures go to link on top left of this page and click "gallery" then blue upload button. AFter uploading pictures, make a post and click "my media" next to smile icon. Here is the picture you refer to with the red arrows. Some of those arrows point to "stringing" caused by a tiny drop of filament on the nozzle pulling off when it touches the infill on non-extruding moves. This is normal and not a problem as it is hidden *inside* the object. Now you also have a problem with the "tops" of certain parts of the face - these spots are not getting enough time to cool so the hot nozzle is basically mixing hot pla in a soup which doesn't have time to cool. There are many solutions to this - for sure make sure your side fans are at 100% by the time it gets here. You are still new and I have already posted tons of advice on this so I'm just going to suggest one thing - check "cool head lift" and minimum layer time to maybe 5 seconds. Alternatively you could print two of these objects at the same time but then you might have external strings. Or you could print this part vertically instead of laying flat. The Z axis has much better resolution than the X/Y axes which are limited to the .2mm radius of the .4mm diameter nozzle. Above you posted an image of your settings but there are 3 pages of settings - not two. Go to "expert settings" to see the rest. Next time maybe publish all 3. I've never gone below .1mm. I don't really see the point when the nozzle diameter is .4mm. If you change your nozzle to .2mm - well maybe then it makes more sense to go to Z steps smaller than .1mm.

Brim and levelling Yes, regular photocopier paper. Marlin assumes that you are levelling .1mm off the glass which is typical photocopy paper. This looks bad. This does *not* look like underextrustion (although it is possible). This looks like bad levelling. Whatever you have been doing - just go a little bit closer (tighter on the paper). Just a little! This one is about perfect brim: There are many other pictures where brim is squished too thin or to spaghetti like on the same topic here: Posts #6-too thin, #11-too spaghetti and #20-good (the ones with the blue cubes): http://umforum.ultimaker.com/index.php?/topic/4210-getting-started-settings-tips-to-nice-prints/?p=34779

I suspect the PCB is fine and it's something somewhere else but who knows. It could be simply a bad solder connection somewhere I suppose. Or a blown diode or transistor. I suspect wiring even though you say you replaced it. Yes you can use the LED signal - the circuitry for the LEDs is identical to the fan. In both cases it puts out a pulsed 24V signal. Check out the bottom left corner of page 8 of the pdf here which shows the schematic (click raw): https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_%28x1%29/Main%20Board%20V2.1.1.pdf

Oops - yeah it is 19V. You definitely don't need a flyback diode. You should purchase a fan that can handle 19V. I guess that 12V fan you bought can't handle it. Yes. I'm sure you don't have any shorts yet. The only short was probably from the new fan which didn't take the 19V very well.

You should be able to go several spools of PLA between cleanings. Are you printing in a very dusty environment? If dust gets in the pla it ends up going through the bowden and gets stuck in the nozzle. You can test the feeder and the nozzle seperately if you want. The feeder should be able to pull around 5kg (similar for both UM original and UM2). Here are some hints on how to do a pull test so you can decide if the feeder is the problem: http://umforum.ultimaker.com/index.php?/topic/4222-pulling-force-of-um-extruder/?p=34887 Please post a photo of your feeder and also of your print head. There are so many things that are easy to screw up.

Not surprising. You should really get a multimeter. Did you check the wiring underneath the UM2? Under the cover? Did you do the method of turning the fans on that I posted a few posts ago?

Wallan you seem to be doing some great experiments. I would love to see what happens if you take the gcode from either of the most recent photos and load it into repetier host. It is a VERY easy program to use and it is free. Once you run it just drag and drop your gcode file onto it and see if the bumps are visible. http://www.repetier.com/download/

I have also noticed that speed can affect bumps (photo of pumpkin in post #12): http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=24010 I don't know what causes this but I think it is because when you speed up and slow down, the extruder has a lag. A delay. With the lower speeds, the head moves at a more constant velocity (less slowing down) so you get more even flow from the extruder. This problem doesn't seem to occur on simple parts like a sphere or a cube, but on something more complicated like a pumpking or a human body it does happen.

Okay - now you want to talk about two issues? :eek: :-P 1) Your bottom layer is very very underextruded. Maybe it is simply because your levelling is off. I think you need to redo the levelling procedure - you don't need to adjust the 3 screws at all - after you do the 1mm thing at all 3 spots put the paper in the back under the nozzle and spin the knob until it is just barely tight. Alternatively you could unscrew the 3 levelling screws by a half turn each. I recommend you do the procedure - it's very fast if you don't touch the screws. Alternatively something could be wrong with your extruder system. The layer height of less than .1mm with a speed of 35mm/sec and temp of 210 is very easily achieved. But the *first* layer is not so easy - you are printing at twice that thickness (or more) at .2mm. Now .2mm is a reasonable first layer thickness but 210C is pretty cold for that speed of 30mm/sec and my printer can handle that easy but some printers can't. Try setting the temp to 230C for the bottom layer and then lowering it to 210C for the rest. Also you might want to move your filament onto the floor as the angle that the filament comes into the feeder can cause quite a bit of friction. Could you please take a photo of the feeder on the back of your machine? 2) As far as lifting corners. If you are printing something small like in your photo, then you should only need to do 3 things: brim, heated bed (60C is enough), glue If you want to print something more than 10mm long then consider going 70C (75C is too much don't go over 70C) which will keep the bottom few layers of PLA above the "glass" temp. As far as what glue - the gluestick that comes with the machine is great. Or use a wood glue/water solution. More details about getting the part to stick to glass here: http://umforum.ultimaker.com/index.php?/topic/3404-printing-on-glass/

NO DIODE NEEDED! I just looked at the BD679 part and it has a flyback diode built into it. So no need for this. I should have guessed this in the first place! The people who designed this board (rep rap people originally?) knew what they were doing. The switch for the nozzle heater also has a flyback diode but in that case it's a separate part. That's what got my thinking about the fan.

It's actually 12V, not 19V. I just checked the schematic one more time. The voltage is lowered from 19V to 12V at IC1. The 12V signal is called vcc/2 for some reason. Why don't they just call it 12V? Anyway that is the signal that goes to the fan. The other side of the fan goes to the darlington transistor which grounds the fan when you want to turn it on. The flyback diode is a great idea. I'm thinking maybe there is already one built into the first fan. You certainly don't need two flyback diodes as one will take care of both fans. You could put the flyback diode on either fan or on anywhere in the fan circuit. This post has too many errors. It's 19V and there is already a flyback diode as mentioned in the next post.

I always assemble and disassemble at 180C. It means I have to use tools instead of my fingers but that always works best for me.

Yes, true! But there is another problem with 1.75mm filament that causes other problems. But, um, I completely forget what that was.

Good to know, thanks.

gcodes for Marlin (and a few other firmwares) great reference: http://reprap.org/wiki/G-code scroll way down to the gcodes on this page: https://github.com/ErikZalm/Marlin/

The gcode is quite readable with a little practice. A few settings are sometimes included in comments at the top. Pay particular attention to "Z" so search the file for "Z" and then also look for feedrates or "F" commands. These are 60X larger because they are in mm/minute, not mm/sec. So F1800 means 30mm/sec. F6000 is 100mm/sec. Also look at temperatures. Also look at temperatures of both bed and nozzle. They might not be mentioned at all in the gcode. By default Cura creates "ultigcode" mode files for UM2 which lets the UM2 decide. But the coffin cube may have been sliced in normal "reprap" mode which specifies bed temperature and nozzle temperature. To get a perfect bottom it helps to print hotter, and to have the heated bed at a higher temp. 60C should be plenty warm - I would print the first layer nice and hot at 230 or even 240C and print it extra slow - 30mm/sec maximum. This allows the filament to flow into cracks better and get a smooth bottom. Also you want your levelling high enough such that the bottom layer is squished flat a bit but not so high that the extruder skips backwards. Levelling has to be more prefect than normal for a perfect bottom layer. Also disable combing maybe as that can cause the head to make a diagonal pass through your perfect bottom layer and make a line in it during the travel move - instead it's better to have it retract. Although for the coffin cube there probably isn't much of this kind of movement. I usually leave combing on.

Mine doesn't move. It is supposed to move but it doesn't. I decided this was better.

@johnnyB, please grab the latest eagle software - it's free so next time you will have this at your fingertips... Where to get circuit diagram: ULTIMAKER1 The circuit diagram, and board layout are here: http://reprap.org/wi...er's_v1.5.7_PCB There is a zip file at the top. It contains the "brd" file which is the layout. Also the "sch" file which is the schematic. Both files can be opened by eagle software which is free: http://www.cadsoftus...download-eagle/ ULTIMAKER 2 SCHEMATIC https://github.com/U...aker/Ultimaker2

That is a darlington transistor. It is already operating near it's limit. When the transistor is fully on it is quite happy as all the energy is going to the fan. When it is off there is definitely no problem either. But when it is switching between on state to off state, if the fan is inductive, it can generate thousands of volts potentially which can blow up the transistor. It's the same circuit for making sparks for a spark plug in a car. There should maybe be a flyback diode. However from your failure mode I think the fan failed first and that caused the failure to the transistors. Q4 breaks quite commonly and it has two fault states - always on, or always off. You might also want to know that the Marlin firmware has two different pulse modes for this fan: fast and slow. Slow mode supposedly is less likely to damage Q4 but fast mode is less likely to interfere with the temp sensor or something like that. You have to choose which mode when you compile and create a version of marlin. I think the versions that come with Cura are 'slow" mode.

You will get sharper/better results when the fan is at 100% yet the default settings I believe don't have the fan come on until 5mm above the bed. Also you will get sharper/clearer results at slower printing speeds such as 30mm/sec. I recommend you put all the different combinations to test on a single test piece and print them all at the same time.

Also as you use up the filament the curvature is stronger as you get towards the center of the spool. The stronger curvature can be very significant in the resistance both in the clear bowden tube and also the white teflon seperator (you can see part of the white piece touching the spring in the head). Also small black pieces of ABS plastic gets ground off the black feeder on the back of the machine and these tiny pieces of plastic can get stuck in the inside of the nozzle. If the ABS is the only problem the fix should be to remove the nozzle and melt/burn out any plastic then soak in acetone (which dissolves ABS but not PLA).

Are you using normal filament or something extra soft? It really shouldn't be chewing up your filament. Maybe you are printing slightly too fast and/or cold? What is your: 1) layer height 2) print speed 3) print temperature? If you go too cold and too fast it will underextrude and either the feeder will slip or it will chew up the filament.

The feeder spring should probably be set to the lightest tension which means you need the white square all the way up as shown in this picture: Here is what the inside looks like:

Yes. Sort of. In machine settings, set the ymin value larger than ymax. If it's only 1mm larger it will be tricky as you need to get the parts closer than that distance between them. So make it 5 or 10mm larger and postition parts so close that they move each other around. This will force it to print rear to front. But it will give you 5 to 10mm less space between parts.

What height did you use in tweakAtZ? Maybe you set it to a value taller than your print?