gr5

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".

Well I got my kit just 4 months ago today and the wood was still printed wrong. However, the nice thing about the current instructions is that if you fix the printing on the wood, the instruction corrections will still be correct. Have you taken a look at a recent laser-cut "bottom" piece to see if it's fixed? You can check it against the picture here: http://wiki.ultimaker.com/File:Endstops.png

You issues look more like you are printing too hot than too cold. I see no regions of under-extrusion. If I tried to print at 210C you would see lots of under-extrusion but I guess my thermocouple is off or something (maybe too much air from the fan hitting my tip). Anyway, here are some samples of too low and too high temp (not my pic but it's very helpful): http://umforum.ultimaker.com/index.php?/topic/1763-bad-surface-on-printed-parts/?p=12318

Nice! Someone who actually knows how to use the MAC! This is why I don't use Macs - I know details like this for the PC but don't want to spend 5 years learning every little feature of the Mac's os.

If you are a competent and experienced c coder - definitely look over the firmware. It's well written code for the most part and easy to read (the parts I've looked at). Also don't be discouraged by all the steps to build your own Marlin. I was nervous it was going to be very complicated but google told me everything I needed to know and I think it took less than an hour. I found not one, but a few places that gave me step by step instructions for installing the compiler, getting the source, editing the config files and getting my own custom Marlin build. This was necessary anyway at the time because at least then (early january when I added my heated bed) Daid's page didn't work right for heated beds. Daids marlin builder page was *very* helpful in createing a configuration.h file - I was able to diff Daid's versus the default to see what I might want to mess with: http://daid.eu/~daid/marlin_build/

The instructions were finally corrected (by me) just a week ago (I took this picture last November): http://wiki.ultimaker.com/File:Endstops.png

The thing that makes this print the most difficult is just all the skips: Where the extruder is expected to stop down to zero and then instantly go back up to extruding again. What happens is you often get stringing where it is extruding when it isn't supposed to be (the extruder doesn't stop fast enough) or you get under extrusion during printing the skin, or you get over extrusion when the head slows down. These can cause the walls to be thicker or thinner at different layers. XY belt play can also cause layers to shift so I thought possibly that should be elminated since you mentioned it. But if it's extruder issues... Some people try to fix this by having the extruder reverse directoin by 2mm or even 4mm. This is called "retraction" it can help, but sometimes it just makes things worse because the head pauses during the retraction. Another thing that helps is to have very fast travel speed and very slow print speed so there just isn't much time to make thick strings. Say 50mm/sec for print and 250mm/sec for travel. Another thing that helps is to have a lower print temperature. This is so the plastic is more like paste than like honey. That also makes it so that the extruding stops faster when it needs to stop and starts faster when it needs to start back up. The fan can also make a difference - possibly if you turn the fan off you can go to a lower printing temp. If you go too low with the temp, then the pressure gets too high and you can get underextrusion (not enough plastic all over) which looks kind of like lots of holes everywhere evenlyish spaced.

Well if the belts seem even slightly loose to you maybe you should tighten and loose belts would definitely cause what you call "shifting": http://www.thingiverse.com/thing:24336 http://www.thingiverse.com/thing:10082 http://www.thingiverse.com/thing:16449 Or read the ultimaker assembly instructions - somewhere in there is a great video showing how tight the belts should be and how to tighten them without needing any parts (there's a screw you can adjust). Also tighten all the X,Y pulley screws (10 of them?). Make them verry tight - you-should-be-nervous-you-might-break-something tight, but not so tight that you break something, lol. Another thing to try is printing even slower. I dont' think it's the slicer.

I found the usb cable to be unreliable and only print using ulticontroller and SD card option now. However if you don't want to buy a UC then try to limit noise maybe? No AC fan's or microwaves ovens or hair dryers in the house while printing? It often crashes right at the start or end of the print job (have to reconnect with cura when it crashes). Maybe something is causing a voltage spike then (turning on or off the heater causes noise spike?) so it makes sense to me this would happen part way through the print job but right at the end of a part (or start of the next).

I think it would be great (and probably easyish) to have the "bottom" layer optional. This would help greatly with parts that don't need to look good on the bottom and that are large (have warping issues). With no bottom, the bottom layer would be able to compress a little when the upper layers are cooling and would be less likely to lift and also less likely to warp (almost the same thing). Examples would be a "bust" where it is meant to sit on a flat surface and you don't see the bottom layer without picking it up. The infill would be visible from the bottom and would be a nice conversation starter on how 3d printers work. Or architectural models or anything that is meant to sit on a flat surface. This should only affect the "bottom most" layer and not layers that are higher up in the model (for example the underside of a chin on a face).

Oh! I get it -- I could easily use openScad to remove circular or square regions giving the bottom lots of large holes. This would greatly reduce the warping.

Wow - this is a new one for me. Hopefully someone has seen this and knows exactly what it is. Did you play with the z screw? Turn it by hand. See if you feel anything at the 10mm point. Look at the bed as you move it up and down past 10mm. Does it bump anything? Check all around the edges - see if something is interfering with travel. Could it be fan related? Does the fan come on at layer 50 or something? Please post your Cura ini file if you use Cura or all settings for any other slicer. Most people when asked for settings post 4 or 5 things. Please post everything as it could be something you wouldn't have thought of (like the fan or a plugin). Is this ABS or PLA?

What is your print speed and what is your travel speed? If they are far enough apart (say 50mm/sec and 250mm/sec) then maybe you can skip the retraction altogether? And suffer an occasional string? Also try maybe lowering the temp? Lowering the temp should increase viscosity so that when you "stop" extruding it leaks less (toothpaste is easier to control than honey).

>ust leave a couple of webs in there so it is kinda Lego-esque on the bottom. Oh cool. How can I slice a part so the bottom is open? Does Cura do this? If not, what slicer does? I want it to have a top and sides and infill (maybe 15%) but no bottom. I know there is an option for no top, but no bottom?

I don't know other operating systems quite so well, but if either of these things happen in windows you can press Alt+space which opens up a context menu for the window. then press "M" for move and then use the keyboard arrow keys (press any key once) and the window will be brought back on screen. This works for Cura, this works for pretty much any window that is moveable. You don't have to plug another monitor in to find that missing window.

It would help a ton if you could round the corners of the base - reduce curling/lifting. Also if you use blue painter tape on your bed, put down fresh tape and wipe with isopropyl alcohol (aka rubbing alcohol) before you print as this will help the print stick to the bed immensely. In fact if you don't do both (isopropyl wipe and rounded corners) I doubt you can print this. Alternatively you can add a single layer flat circular thing at the bottom of each corner. One layer thick - shaped like a quarter or bigger. Having a sharp corner puts all the force at a single point and makes it more likely to lift. Having a curved corner makes it strong. Then cut off that thin piece after printing and sand it down. The support needed for the roofs is ridiculous. That will take a very long time and waste a lot of plastic. I like the idea of printing this as at least 3 seperate parts with the roofs upsidedown to reduce the time and waste. Or even better, print the roofs seperate - call it a feature. "I made the roofs removable at no extra cost!". That way they can be printed rightside up and the yuky support will be hidden under the roofs instead of visible on top.

I have a set of very small files. They are useful for many purposes including cleaning up some parts after printing. I used one of these to file flats on the 3 motor shafts and I think the Z screw maybe but nothing else. The 8 gears with the long belts - you can't file flats on these because you will have to adjust them *after* assembly. Or maybe someone knows how to do it but I certainly don't. Just tighten these extra tight once you have things square (perpendicular). As far as other cusomizations or modifications - well there are several. I had to adjust the positions of washers for the extruder (and manufacture my own extra washer). I had to cut some bolts for the fan cover. I can't remember what else. This is a kit. UM tries to do a good job on the kit but there are mistakes, issues, things that don't quite fit - oh yes, I had to do tons of filing of the plywood to get everything to fit. The bed was probably the worst. Anyway, since you can't file the 8 pulleys flat then there is no definite need to file flat the rest either. I just removed about a half a millimeter of material. It's easier than you may think but optional.

>Like if I have the initial layer thickness set to .15mm, does that mean >the machine is expecting the Z-home to be .15mm off the bed, or does >it move the nozzle .15mm above Z-home? If your initial height is .15, Cura will home your machine - call that zero and then move z up by .15 when printing the first layer. Whatever the initial layer height is set to (.3 default?) it sets the z to that height when it starts printing.

Keep in mind that the above picture applies to a given flow rate of plastic through the head. If you print faster or slower than jake did (he made the picture, not me) or if your layers are thicker or thinner, this will change the amount of plastic flowing through the print head and will affect the temperature. You need higher nozzle temps at higher flow rates for the plastic to come out at the same temp. Also different dye colors and different manufacturers of PLA have different viscosities at a given temperature.

Other ideas: Turn off fan for layer 1 print layer 1 extra thick (.3 mm) print layer 1 extra slow 20mm/sec heat the blue tape with a hair dryer just before printing so it is closer to 37C (body temperature) - of course 70C would be ideal. set nozzle temp higher by 20C for first layer then lower using ulticontroller or Cura gui All of these help.

This is an extremely common problem. If you are using PLA you shouldn't need a heated bed to keep it sticking but a heated bed is one (expensive compared to others) solution. My favorite solution is to use blue painters tape on the bed and to wipe the tape with isopropyl alcohol (aka rubbing alcohol - found at any drug store). In fact you may have a new problem - removing parts from the bed Also you could round the corners of your box. Or add a single layer of material beyond the edge of your box with a large round radius on each corner. Or you can use the Cura option to print a "raft". If you have pointy cornered box, all the lifting force is strongest at one tiny point at the corner of the box - once that lifts, it keeps going. However if you have rounded corners the force is distributed across the curve of the corner. But again, you shouldn't have to do any of this if you use blue painters tape (came with ultimaker - available wherever you buy house paint) and clean it with isopropyl alcohol. I think the alcohol removes the glue residue from the layer above when the tape was still in the role.

I'm more worried about your heated block. I think you might want to rotate it 90 degrees before you power it up. If it is touching the fan shroud, it will melt the plastic of the fan shroud and allow cold air to touch the tip of the extruder which will cool the tip too much and mess up your prints.