gr5

I believe the springs come from wooden clothespins. They should fit perfectly. Something like this:

I had to put a treat under all that to get him to go closer. He is such a nice dog he was afraid to disturb the stretchlets to get at his treat so I had to push a few stretchlets out of the way after I took the pic so he could get it.

STRETCHLETS! Making 500 stretchlets for a big event coming up in 2 weeks.

There's only 2 screws holding the bottom plate underneath the UM2. The screw heads are under the bed. You can lift the bed up when power is off by just forcing it up - lift form the back. About 10 to 20 pounds force. But usually connection problems occur where the cable meets the heated bed. Either where the screws tighten down the wires or where the connector solders to the heated bed.

Wow!! Very Nice! 1) How did you do the orange label on the side? Did you print on some kind of peel-off label? Please link to the product or technology. 2) How did you get those black sliding blocks? Did you steel those from the J-head also? Did you laser cut those blocks somehow?

I added a note to that posting you link to. I think Eldrick has a UMO only so although he's pretty smart and usually gives good advice I think he goofed on that one [oh wait a correction to my correction - evidently volumetric is fine if you add an M200 command]. I had read his comment before and didn't notice the "volumetric" issue and even if I had I'm not sure I would have known that he was wrong at the time. But I have been using reprap mode quite a bit this week for a stretchlet project. I'm hoping to print 500 stretchlets.

*not* volumetric. Some printers evidently move the filament by volume but Marlin expects filament movements in mm, not mm^3.

Did you look at the z switch? Often something falls down into that hole. There is a screw sticking out the bottom of your bed that sticks down into the hole where the z switch is. It's probably stuck. Anyway you can turn of power and test the resistance of the z switch with the switch pushed and not pushed.

It would be good to compare a .4mm e3d nozzle versus UM2 standard nozzle versus the upcoming JET nozzle. The main difference would be in the size of the actual hole (it's supposed to be .4mm) and how flat the tip is and how big the "shoulder" is. A larger shoulder is better at pushing down the outer shell layer when "drawing" the inner shell layer which is helpful on overhangs. Too large of a shoulder and the quality looks horrible.

The single bad layer in the white print is probably due to a tangle in your filament. Next time maybe uncoil more of the filament, or maybe put it on the floor or check that it isn't kind of in a knot by unrolling a few meters and rolling it back up. The blue part looks underextruded inside. Try not to go over the below speeds for *.2mm* layers. For .1mm layers for example you can go twice as fast: 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C

Nothing wrong with autocad.

Could you be removing the SD card too soon? Before everything is written? Or maybe it is a defective SD card? It sounds like you need to inspect the file on the SD card after saving it.

I can see in the walls of your print some underextrusion here and there. The top is hard to tell what the issue is - it looks like you only have 2 top layers so I would thicken that. Please post: print speed, nozzle temp, layer height. For example for .2mm layers you don't want to go faster than these speeds: 20mm/sec at 200C 30mm/sec at 210C 40mm/sec at 225C 50mm/sec at 240C

When you switch to "rep rap" mode several settings in Cura suddenly appear: Nozzle Temp Bed Temp Filament Diameter Retraction distance Retraction speed I suspect the "filament diameter" setting is wrong. It should normally be 2.85. I'm printing on a UM2 as we speak in reprap mode and it works fine for me.

@aviphysics: The UM2 is strange in this way - normally we use cura in "ultigcode" mode which doesn't specify the start sequence anymore - so the homing, priming, warming up is all done in firmware now. Unless you export to a gcode file in "reprap" mode. In that case it is all done using gcodes. Supposedly the advantage is you can slice once for an ABS and PLA part and separate the slicing process from the material used. So on the UM2 you select the material which sets approximately 5 settings (bed temp, nozzle temp, retraction distance, retraction speed, fan speed multiplier (if at 50% then all fan commands do 50% of what gcode asks for)). I don't really think that's much of an advantage as I never print the same part in 2 different materials.

Did the thermocouple fall out? Check that first. There are many things that can cause this so you need to isolate. Measure the voltage coming from the top of the head. The voltage should represent the temperature "directly" like this: 0V=0C 5V=500C 200mv=20C Then heat up the head so that it feels warmer (at least 30C) and measure the voltage again. If the voltage is correct (voltage goes > 300mv) then the problem is in the cabling or underneath the UMO. If the voltage stays at 200mv then the problem is at the circuit board or the thermocouple. This is a first isolation step. If you don't have a voltmeter, find someone who has one and have them show you how to use it (have them do the measurement!).

Bagel Orb - I suggest you just read the code. As a programmer I have learned that reading other people's code may be a little frustrating at first but you may learn some tricks and also you will understand exactly what the plugin does and you can decide if it's useful at all. A very nice feature in Cura would be for it to make more perfect bottom and top surfaces. So "hop on move" for surface layers and "retract on move" for surface layers might be nice (not all layers - just the outer most layers).

Hopefully in cura the clips are shown on your computer dispaly as *right* of center. If not Cura still needs some corrections. Cura shows the build area - not the actual glass. The build area is shifted left because the nozzle is shifted left. The plan was to have dual nozzles where the second nozzle (on the right) would print more to the right. The black plastic print head comes very very close to hitting the black plastic endblocks. That's what usually physically stops travel (although sometimes the fan shroud hits the wall first). The tolerances for travel are very tight. This gives you about 230mm. But you need the head to stop before it hits either endblock because there is a danger that the stepper motor will skip a step. So to get 230mm you need the limit switch "just right". Maybe 1mm from hitting the left end block. If you bend the end stop, now your travel is say 1.5mm from hitting the left end block and now it will hit the right end block that much sooner. You can tell the head to move to position X=230mm but it might not actually reach that position. It might even loose a step on the stepper. More likely the belt will stretch a bit. If you try to print something that uses the full 230mm you will see the problems. If 228mm is plenty of printing space for you then go ahead and bend the limit switch.

Borders warping up is common for overhangs. It has more to do with the fact that PLA shrinks in the first few milliseconds and is laid down like a liquid rubber band. Like snot. and pulls inward which means upward if it is an overhang - especially on the corners. Fan helps a lot. TONS of fan. 200% fan. Extra fans. I don't know anything else that helps. Although printing super slow - 5mm/sec on the next layer up pushes those "warping upwards" on the next pass (they remelt but you have to go very slow - 5mm/sec). I never went for the 5mm/sec solution myself. Instead I support overhangs sometimes with CAD to hold them down.

There are people with the form1 also on 3dhubs. The prices on 3dhubs are quite good and you often get someone local so you can actually go pick up the part and chat with the person about how they like their printer. The UMO has basically identical quality so if there is no one in the area with UM2 consider UMO. Your part will print fine as shown - the biggest issue is the 45 degree overhang underneath the part. The top is fine as UM printers are very good at bridging a gap (when it starts printing that flat ceiling it just bridges across from the center and outer rings). The 45 degree overhang will have some ugliness - bumps and such but it will be minor. If that surface needs to be dimensionally accurate then you will have trouble fitting it in proper position. Personally I would print it as shown. No support added.

You can't use linear bearings in places where the rod is also rotating. So in the 4 blocks you need brass bushings but for the head itself you can use linear bearings. The guys who designed the UMO were pretty damn smart - be careful if you think your idea is much better. But there are certainly things that can be improved upon.

The smell coming from the Ultimaker when printing PLA is actually kind of pleasant. It's subtle - I have to be within 2 feet of the machine usually to smell it. Some people say it's similar to cooked popcorn. The amount of vapors (oils) that get into the air is tiny compared to say frying bacon or a grilled cheese. It's similar to a small candle. Scented candles put out much more smells. If a scented candle drives you crazy and gives you headaches and scares you (carcinogens) then consider venting but not otherwise. ABS and Nylon are a bit worse. I can smell the ABS sometimes (just barely) 20 feet away in an open area. It's still much less than a scented candle but more than just one plain candle. I've been to places where 10 printers are printing at once and you don't normally notice any smell at all. You really have to stick your face right into the machine and concentrate. So if the candles in a church for example don't bother you half way back in the pews I don't think you will notice. I keep referring to candles and fried food because the vapors are created similarly - by heating oils to high temperature. You get the same sort of aerosols from a candle or by making a grilled cheese sandwich as you do from heating PLA.

More about the Olsson block here: post #329: http://umforum.ultimaker.com/index.php?/topic/7689-custom-heater-block-to-fit-e3d-nozzle-on-ultimaker-2/?p=95991

There is a problem: "nozzle can hit clips" yet you are trying to fix it by "centering" the print. Well the print can't be centered unless you center the nozzle in the head. Currently the head should be able to come within 1mm of the left and right blocks. So you can "center" by maybe 1mm at the most. But the more you move the X axis endstop to "center" your prints, the smaller your build volume will be so don't move it much. Since your fan is hitting the left side you should consider either bending it in a bit by pushing hard on the metal fan shroud. Or bending the limit switch out by a tiny amount. As far as the problem "nozzle can hit clips" this is the true issue. Daid may have fixed this in the latest version of Marlin because he fixed it I believe for the Ultimaker2 go and the Ultimaker2 extended. So in other words this might be fixed in latest cura.

There's lots of other unimportant or minor differences. From the perspective of building your own - the electronics is a big deal. You might even want to go beagle-bone instead of ramps. I want to upgrade my UMO (or UM2) to beagle bone controller some day.