gr5

You'll have to build it the hard way - yourself. google marlin. There are at least 2 detailed posts out there that describe how to build it yourself with step by step instructions. There's a lot of steps (e.g. you need the arduino IDE) but it's not too bad. I was able to do the whole thing (including lots of time reading the configuration.h file) in about an hour. The configuration.h file is where you set things like heated bed settings.

You have 2 issues. The holey pattern is typical under extrusion. Not enough plastic is flowing. Not sure why but I would try increasing temp by 10C or slowing down quite a bit as illuminarti said. More visual examples of underextrusion here: http://umforum.ultimaker.com/index.php?/topic/1763-bad-surface-on-printed-parts/?p=12318 Your other problem is very common with large parts and is caused by upper layers contracting and pulling on the bottom layer. There are a ton of fixes for this problem. I notice your infill is 80% which is the opposite of what you want to reduce the upper layers from pulling the bottom up. You probably won't like this advice but this will help greatly and is easy to do: put a layer of blue tape over the glass. Clean the blue tape with isopropyl alcohol (this is critical!). Your curling issue will probably go away. (don't forget to re-level). This will work better than anything else you can do. If that's not enough or if you don't like that idea, you can consider adding vertical holes in your part if that works for it's purpose. Also round the corners of your part - sharp corners lift more easily than rounded corners because all the force is on the tip of the corner. Also use that heated bed if you have one. Heat the glass to 70C and print the first layer at 240C, no fan, 40mm/sec then dial the temp down with cura or ulticontroller after it finishes the first layer of the part (not the bed) (this improves the stickiness).

Sometimes smaller layers come out worse for me. I try to stick with .2mm and tune everything for that. Anyway, my only suggestion is that to fix the top of your owl, in cura, the "bottom/top thickness parameter, under "fill" section should be 2 or 3X the value of your layer height. So if you are doing .075mm layers, make this either .150 (two layers on top of owl head) or .225 (three layers). This will greatly reduce the likely-hood of holes. I'm not sure if your blobs are due to overhang but if so then greatly reducing the speed will help. I can get almost horizontal printing at 20mm/sec. If you have an ulticontroller and are printing at say 70mm/sec then when you get to the chin of the owl dial it down to 40% (50 * 0.40= 20). This might also help with the top of the head. Else if using cura, then go to the tab with speeds and lower the perimeter speed to 40%.

This is classic "under extrusion". You could be slipping in the feeder - maybe you could try tightening the feeder. More likely you can fix this with higher temp. What temp are you printing at? Since this model has no stringing problems (for example if you had 2 vertical posts, you might get stringing between them) you could go up to 240C no problem. But later on other models you will get stringing so maybe just go up by 10C from whatever you are printing at now. Or slow things down a little bit to reduce the pressure in the print head. See this also: http://umforum.ultimaker.com/index.php?/topic/1763-bad-surface-on-printed-parts/?p=12318

I'm sure it was missing a partial step on every layer to be that consistent. I think these servos are driven in 1/8 step increments maybe? Does that make sense? You could have also fixed it by lowering "jerk" and acceleration to ridiculously low values.

If you tell Cura the nozzle is .4mm, then it will print everything .4mm towards the center of the part. If it didn't do this your part would be .4mm too small. But this is usually not enough correction. If you are printing a circle and you are printing fast, I often get a circle smaller than the movement of the print head. It's like you are stretching the plastic around a circle and it pulls in a bit. My outer dimensions also tend to be a bit small but not as bad as the inner dimensions. Anyway I do the same thing as Bill. I print twice. It's wasteful but I don't print the whole part - just the area with the critical dimension. Then I measure accurately and adjust my model. If you tend to have holes of similar sizes or slots or lengths, and if you print at consistent temperature and speed, then you will tend to need a consistent correction factor. Also some people when printing 3mm screw hole print at 3mm knowing it will be too small but then sort of self-tap the screw in there and it comes out great. Also vertical holes and horizontal holes may have different issues but I've never printed a critically dimensioned horizontal hole.

It's subtle. Print something simple and watch the belt the goes around the x-motor. If it's touching the back panel it will twist a different direction every time it switches direction.

I had the exact same problem on my X motor. I head scratched about it for hours until I noticed the X motor belt was twisting due to lightly touching the rear wood panel. I added washers to the existing black plastic spacers for the motor mount (and also mounted the x motor pulley as close to the motor as I could without it touching - maybe .5 mm?) and the slanting problem went away! By the way the slanting is caused by missed steps in the X motor servo.

I have found that overhangs print much better at extra slow speed. 20mm/sec is the slowest I've gone and they look better at that speed than at 50 or 70mm/sec. It might have to do with not enough fan - not sure, but I can see the problem as the filament is being laid down - the filament pulls/shrinks as it is being laid down and doesn't go where it is supposed to but if you slow it down it goes to the right spot - I know some of you are thinking it's a belt issue, but for non-overhangs I can print no problem 5X faster. Anyway I'd be tempted to dial down the ultictonroller to 40% when you get to the overhangs.

What is your print speed? I've seen this before but not this bad - I certainly don't have this problem at 70mm/sec.

Don't just trial and error your thermister. Presumably you bought it from somewhere and there are specs for it? These thermisters come with a formula. You can use the formula to generate your own table if there isn't one in the firmware already. There's a bunch in thermistertables.h. Or if you have an accurate thermometer you could calibrate the thermister yourself at 10C intervals

In configuration.h in the marlin build you want the following commented or not commented as shown: //#define PIDTEMPBED //#define BED_LIMIT_SWITCHING #define MAX_BED_POWER 255 // limits duty cycle to bed; 255=full current If you haven't built your own Marlin yet, well, I recommend it. It's not too hard. You have to install the arduine IDE and you have to download the latest Marlin (which I'm pretty sure has some key bugs fixed that aren't in cura yet). There are instructions if you google about how to build marlin. Very detailed instructions. It ended up not being so hard. To get help on what to comment in and out in configuration.h I read the comments in there and I also used daid's web page and looked at the configuration.h that came out of that.

Look at the knurled bolt, make sure the sharpest part touches the filament. Put some filament inside the feeder. Does the spring compress when you close it? It should. Try turning the large gear by hand. If everything seems fine, heat up the hot end to 200C. Then try turning large gear by hand again. In Cura, the temperature is the first window, and x,y,z,extruder can be controlled in the next tab. But I prefer to use my hand for the turning the extruder/feeder.

Probably be fine but kapton tape can handle the heat no problem (I think it can handle 600C maybe) so you could unwind your twisted pair where it will be touching the heated bed and use kapton tape to keep the two strands from touching. That way if the insulation ever melts it won't mater.

Printing temp is very important. If I use > 220 I get stringing because the plastic is like honey. If < 200 I get under-extrusion. If I'm printing a part with no jumps (like a gear) I will print at 240C and print 2X faster. Or if I don't care if it comes out ugly (strings/blobs). If I'm printing something with e.g. pillars - with a hop on each layer or lots of hops each layer I print colder. Like 210 or 220. Different speeds require different temps. Different colors and manufactures of PLA require different temps. Do an experiment. Set nozzle to 200C. Disengage Feeder and push filament manually with one hand holding feeder in place. Then stop the pressure. How quickly does extruding stop? How fast is the leakage? Repeat at 240C. Huge difference. Now you know what to look for so go back to 180C and repeat at every 10C interval. Do this every time you buy a new filament. Make notes. Try to notice how much pressure is required.

If things aren't sticking well - if even the skirt isn't sticking well, I check leveling again. It's usually because my bed needs re-leveling. I use a slip of paper and I expect to feel the paper stick under each 4 corners. I like 240C for the first layer and then lower the temp to anything from 200 to 220 depending. 240C is just for good sticking the first layer. Also print very slow. If you have ulticontroller set to 50% or tell cura to do first layer at 20 or 30 mm/sec. But usually 40mm/sec is slow enough for smaller stuff (just first layer). Also I like thicker first layer (I think cura defaults to .3 which is great for me). Also have fan off for the first layer. Another cura setting. The skirt is also important for me as I can use it to test stickiness. If the skirt isn't sticking even just in a few spots then I abort the print. Give the skirt 5 seconds to cool and try to lift with thumbnail. it should stick well. Maybe even move your bed enough to mess up your print if you aren't careful. Rubbing alcohol is sold anywhere bandages are sold. Drugstores. In the USA, CVS, Walgreens.

What illuminarti said. I thought he was full of it until I tried his technique the first time. Amazing. Your next problem will getting the damn parts off the bed. Regarding "the coral look" - that sounds like underextrusion. If you are going to be printing that fast (which is a good goal!) you need to at least raise your printing temp to allow that plastic to flow! But you will likely have problems on parts with gaps in it (stringing) if the temp is too high. Other things that help with warping/lifting is rounded corners - makes a huge difference. Or checking that box in Cura that says "add raft". Or get a heated bed but getting a heated bed to just make PLA stick better is a waste of money when isoproply alcohol works better and more cheaply.

Did you use Cura to slice the robot? Did you go through the Cura wizard where you check limit switches (aka end stops)? Did Cura load the marlin firmware into the ultimaker? What version of Cura do you have? Assuming you got through the above just fine... Assuming you don't have an ulticontroller, and assuming you are using Cura connected through usb, click "print". Control the X axis and Y axis. positive values in X should move the print head to the right. POsitive Y values should move the head towards the back. Is the X motor backwards? Maybe the wires were soldered to the X motor backwards if it moves the wrong direction? I believe if you wire the servos backwards they move the opposite direction. There's also a flip bit in Marlin somewhere to flip any of the steppers.

Consider lowering your fan - did you change fan settings recently? Is the fan cooling the tip too much? I print PLA at 240C all the time. I know I'm weird but it works well for me. Don't be afraid to do some test cubes or something at even higher temps. Owen may be onto the actual problem - possibly some blockage. Did you recently start printing faster? Faster speeds might need higher temps. Look at your fan shroud - did it break? Or get ripped open? Is the air suddenly on the tip? Did you recently change fan settings? Maybe your new filament just needs to print at 250C. Or at least 240C. Experiment. Maybe the new filament is larger than 3mm in diameter in spots and gets stuck in the tube (which is not much larger than 3mm and sometimes the filament can't fit through the bowden tube - especially when compressed by the feeder).

This is a great example of where one would want variable thickness layers. I would want to double up my layers for these areas. This is referenced in that "paper" slicemeister posted about earlier in this thread.

I didn't notice that! You need to move that fan soon or it will break on the z screw.

Hmm. Try opening the latch on the extruder so the plastic filament can slide freely. With the hot end at 220C, try shoving the filament through the tube. Does anything leak out the nozzle? You can push pretty hard - say 5 pounds of force - plenty that you need to hold the feeder from flying up off the machine. If that works, pull the feed out of the bowden tube a few inches, close it back up, and turn the big gear by hand - you should see the filament moving slowly. Can you see a pattern in the filament where the knurled bolt is cutting into the fillament? You should. Keep turning the gear until it enters the hot end and filament should come out. You may have to rebuild your feeder - the knurled bolt may not have the best part touching the filament or 20 other possible things not assembled right.

This problem isn't really that big of a deal. Some people had the switches backwards and did a home and were afraid of damage after their x axis did a "total slam" but their ultimaker survived (and they were annoyed but so what - deal with it - UM can handle it - so should you). Maybe the new instructions are wrong and messed up twipwip? Twipwip - what month did you order your ultimaker or when did it arrive (roughly) and is the bottom of your ultimaker backwards like the picture? Or is the printing on the bottom of your ultimaker fixed now (I doubt it). If so I'll fix the instructions. http://wiki.ultimaker.com/File:Endstops.png

I assume you are just making fun, but just in case - I meant an hour to read instructions, install the compiler, download marlin, figure out what the instructions meant (where's the bloody open project and build project commands?), read every variable in configuration.h and all the comments and change a few things, and then build it and download onto ultimaker. The actual compile was trivially quick.

By the way, there are tons of comments about how the kit was fixed, plus tons of more messages about how "nope, not fixed yet" months later. It would be nice to have a specific cutoff - something like: "ultimakers shipped after Feb 27, 2013 have this 'reverse x limit switch' printing fixed".