gr5

You might want to print it in this orientation. This will give you much better quality at the tops of every tooth - but the red areas (overhangs) will be worse quality (bumpy). Note the parameter circled in green to help it sit flat on the glass:

I downloaded your model (4-fixed) and sliced with Cura and it looks good. The digital model is excellent quality. There is a bug where sometimes the printer stops early. This is fixed in the latest firmware. Install the cura and then install the firmware from Cura. The red circles are showing areas that are pretty good and I'm not sure what the problem is. The final tooth printed (#23?) has a little spot that can be improved with "cool head lift" but only slightly and this won't affect the other teeth. I don't think you can get much better than this. Also when the tooth gets thinner than .4mm the nozzle can't print any thinner than that so it stops printing the top most layer sometimes as it is thinner than .4mm. You can see this in Cura before you start a print. You could by a UM Original and a smaller nozzle (say .25mm) but of course this means it would also take longer to print. I think you know the answer. With no infill (I dont' think you need infill at all) and no infill bottom and .8mm shell at .2mm layers at 50mm/sec Cura says: 48 minutes to print. With .1mm layers at 30mm/sec (better quality) Cura says: 93 minutes to print If you remove the bottom half of the model (Quality - Cut off object bottom: 10mm) .1mm layers 30mm/sec Cura says: 57 minutes to print I guess in theory it's possible. You would need someone to check the printer every hour to make sure the printer didn't fail, mark each print, and start the next one. Maybe after a week you could get good enough to print 4 at a time over night? You could even program it to let the suface cool for 5 minutes, then knock the part off the platform and then reheat and then start the next one. That way you could print all night long and all day long.

The feeder pulley might be tricky but the rest are straight forward: tighten them so much that the hex driver twists significantly.

After you hit save or whatever there is a non-obvious step where you have to select PLA again. Not only that, but it is kind of buggy in the original firmware so you might want the latest firmware which comes with the latest Cura. With older firmware, after saving PLA settings you have to change the LED settings and then maybe power cycle? It took my about 10 tries. With the newer firmware you just have to know about the last step where you select PLA.

1) I don't know why PLA gets brittle. Mine has been fine - all colors, all brands. I think it gets too dry maybe? I haven't heard any good explanations. I recommend you somehow mount the spool on the floor. Maybe make something with knex? 2) Very strange. This would make complete sense if your rear fan is broken. There is a 3rd fan on the print head at the back. Look carefully. Does it spin? It should start up when you power on the machine - even before the lights come on. 3) Is it too small? Do you have calipers to measure exactly? I would measure very accurately the "error" and increase the model by that amount. Or you can just try 3% as that usually works - maybe change the scale in CURA to 1.03 (3% larger). Or you can scale in only X and Y if those are the problem dimensions. If it is more complicated maybe you have to post a picture?

Extra layer? You mean the skirt? I think you need to post a picture maybe. Click "gallery" in the top left corner of this page, then click blue "upload" button. After uploading start a new post and click "my media" next to smile icon.

Can you post the first few dozen lines of gcode from both slicers please? Up until it starts extruding on the first layer. What is your nozzle hole diameter?

Uneven does not necessarily mean left/right uneven. It could be up/down uneven due to upper layers being warmer other issues. I don't have anything specific in mind. I don't know if Robert had anything specific.

Wow - you answered all of your own questions perfectly! I noticed Cura put a brim on the inside *and* the outside. I think that's fixed in the latest Cura.

There is a sudden improvement in ability to stick to the glass around 40C and above that threshold there is no difference. Use 50C to be safe. Raw data from experiments are here: http://umforum.ultimaker.com/index.php?/topic/3404-printing-on-glass/ For very large parts there is another threshold (glass temp) to avoid lifting/curling if you can't avoid it for any other method. This threshold is around 75C but it is better to improve stickiness than to keep the bottom layers above the glass temp as it will be very soft and easily damaged and printing overhangs will come out bad on the bottom 10mm of the part because they never fully cool.

Make sure you always check your sliced model in "layer view". You can save yourself lots of trouble - you don't want to find out you have something wrong with your model (from the slicer's view) when you get 10 hours into your print!

1) Again, please post the STL somewhere. For example youmagine.com. 2) Did you check the model in XRAY mode? If you see any red then that is a problem area for your model.

Can you photograph your result? I may have made mine worse also! :eek:

Please post a picture of what you talk about. I think this "rim" can only be printed if it is facing upwards. Is this like a coin? Maybe cut it in half and print it on edge?

That loud noise is sometimes called the "death rattle" but usually it is harmless although in your case I think the belt slipped a tooth. Not serious but you have to equalize tension.

If the model is organic you might want to use blender (free). If the model is mechanical you might want to try google sketchup (also free). Both of these will import and edit STL files. Learning more than one CAD system sucks. It takes hundreds of hours using one to get to a level where I can do things at a reasonable speed.

You broke Q4. The darlington transistor. It is easy to replace if you have beginner soldering skills. This large 3-pin part is located very close to the fan plug. It is not an expensive part.

But not *too* tight.

Ah - well there is a 4th source for error! You probably have "play" or "backlash". More information here (posts 7,8): http://umforum.ultimaker.com/index.php?/topic/1872-some-calibration-photographs/?p=14474 You probably need to tighten your Y axis short belt - loosen the motor mounts, slide it down tight, retighten motor mounts. Although play can also be caused by very high friction which you would notice being different for X versus Y when pushing the head around with power off. Friction most often caused by end caps on the 4 rods.

I recommend you use the cura setting "cut off object bottom" under quality and do a few tests where the "top" of your part is now only 1mm off the bed.

78.74 steps/mm means if you ask the X or Y axis to move 1mm the controller sends 78.74 steps to the servo. This seems very straightforward to me. I don't know how to make it clearer. If you want to increase the scale (print bigger) on an axis by 3% then you want to increase the steps by 3%. But I don't recommend this. The steps/mm is worked out pretty carefully based on diameters of pulleys and if you mess with it, the software endstops might not work if you print something at the full 205mm size. The shrinkage you see is caused by several effects. I'd have to see the part to know exactly what the problem is. But PLA shrinking by 3% sounds about right. .25/10mm (your x axis) is 2.5% shrinkage. .45/10 is 3% shrinkage. It sounds like you have identical shrinkage on both axes. So alternatively you could scale up all parts by 2.5 to 3% every time you load a part in Cura. But in practice I think you will find that there are many other factors that change the dimensions of parts. For example vertical holes through a part are always smaller due to 3 factors: PLA shrinkage, the pulling effect as it lays down a "string" of PLA around the outside circle pulls it inward and the fact that circles are done in CAD with a polygons and these are inscribed *inside* the circle. So less than 10 sided polygons noticably shrink the hole diameter. The best solution is to always print a part twice - or print small test sections, then increase the sizes in your CAD to compensate. Unfortunately different brands and colors of plastic will need different compensations and the way you print (temperature, fan settings, speed) will also change these so it's not something that you can share with other people.

Do you have solid infill bottom and top checked? Also you should double check in layer view near the areas that are red in xray view. Xray view sends an imaginary beam of light through your model and if it hits an even qty of walls it colors the model blue or white or light blue and an odd number of walls is a red or dark red color. An odd number of walls implies either an extra wall inside the part, or a hole in a part (where "walls" can be defined as ceilings and floors as well).

You might possibly want to tilt your UM2 on it's side and see if that square nut comes out and save it until you need it. I don't know much about this part of the UM2 so I don't even know if it *can* fall out.

No image attached. Click "gallery" in the top left of this page, then the blue "upload" button. Then after uploading, make a new post and click on "my media" by the smile face.

The Z screw grease is in a very small, clear plastic tube. The grease is green so the tube is green. It should be in the same bag as a screwdriver, a roll of blue tape, and I forget what else. You probably won't need it for a year or so. The grease is *only* for the Z screw. Don't use it anywhere else.