gr5

3% error is tiny. Not noticable in the final part. Did you do this test? I forget: http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

Oh - and all my nozzles are very dirty but I have never *noticed* the fur with PLA before. I pay more attention now so we will see.

I got some fur with some nylon I was printing. I was printing at 260C. I wonder if the fur is more common at higher tempertures? Normally I print PLA at 200C to 220C.

This theory has merit but I should say I've printed 3 hour prints entirely at 190C and entirely at 240C and didn't have problems. However at 190C I was printing slow and at 240C I was printing fast (75-150mm/sec).

I had that curling issue once. Only once. It ended up being a partial blockage near the tip of the nozzle. I fixed it by taking a metal needle (I used a hypodermic needle but acupuncture needles work well also) and sticking it up into the nozzle hole from below and scriping around a bit to clean the surface. Took about 10 seconds. Be careful not to put holes in your isolator (don't stick the needle in very far).

To reduce the qty of polygons follow the directions here (meshlab is free): http://www.shapeways.com/tutorials/polygon_reduction_with_meshlab

Does your printrbot have a heated bed? What is your bed like? aluminum? acrylic? glass? Are you printing PLA or ABS?

It's probably just not displaying the top - I'm guessing it still creates the gcode. You can test this by opening the gcode file in repetier host which has a better "layer view" than cura does and it's free. I've never used raft feature by the way. It's kind of an old technology that isn't needed so much anymore as there are now other techniques.

What? You were eating a hat? I don't remember anyone eating a hat - sorry. But you probably saw me there. I was at the booth about 50% of the time. Bald guy with moustache. Oh gosh - do you have the ultimaker heated bed upgrade? If you do and installed the firmware for that then your thermistor UBIS would probalby stop working. I guess you really need to determine what kind of temp sensor you have in the UBIS - is it the UM original sensor (thermocouple) or is it a thermistor?

What Zoev89 says makes good sense. Probably broke the ADC pin on the arduino. A 100K thermistor should be about 100k at room temperature (actually officially it would be at 25C). A 10k thermistor should be about 10K at room temperature. You could test the thermistor. Then you can put the 4.7k resistor back in and see if the voltage there makes sense (read about resistor dividers on wikipedia). Then if that voltage is correct and Marlin still thinks it is at the wrong temp then it's the arduino that is broken. Fortunately they are VERY inexpensive. Maybe $20 including shipping.

Unlike thermistors, all PT100 sensors have the exact same temperature to resistance curve. Which means you can use any pt100 sensor that will fit. With thermistors, there are hundreds of different kinds of 100K thermistors. All of them are 100K at 25C but are varying resistances at 100C depending on the "beta" value.

On the front of the UM2 the max you can set it to is 35mm/sec so that's a decent/reasonable value. In reality I suspect it can go much faster but haven't tested it out yet and don't know anyone who has.

You should ask the UBIS experts. I don't know what's in a UBIS hot end. Does it have the same thermocouple as on the UMO? The one on the UMO goes through a board on the print head that converts the temp into a voltage from 0V to 5V representing temps from 0C to 500C linearly.

To remove the sensor someone said to put a small wood screw in there that is the right diameter to get a good grip then pull it out with pliers. The sensor is repairable. Split it down the side with dremel, locate the tiny temp sensor (it's very very very small - like grain of sand) and attach it to fresh wires and pack it back in there with maybe kapton tape. Beware normal solder melts well below 230C so you need solder that is mostly lead. Check melting temp of the solder before using it. Good article on melting points of different types of solder in wikipedia. Kapton tape can handle 300C no problem.

What kind of printer is this? Do you have UMO board? UM2 board? Ramps board? Were you fiddling with wires on controller board or on head?

When I get new materials (some day) I will test them. I'd love to do PET. Very disappointing in the protopasta. I have put PLA on something outdoors in the sun and it has lasted 15 months now (over a year) so it's not the sunlight - it's the temperature.

Welcome. I suggest you start here: http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide And then post a picture of one particular problem you've been having. Preferably one issue per posting.

The skinny wires go to the temp sensor (you can see the traces on the board going over to the tiny temp sensor part) and the thick wires go to the heater (you can see those traces also - they cover the whole board). Both objects are pure resistors and can be wired up either way (no polarity - it works backwards and forwards).

@twistx my heart goes out to you! You've tried so many fixes! In some of your posts I think there is a tiny drop of sand in your nozzle but you've cleaned it out so many times! Please update your lcoation. If you are in North America you can get a replacement isolator within a day or two. But much slower in other countries. UM has a USA factory now. I'm hoping the problem is your isolator. The new one came out roughly March 2014. A lot of recent printers have a faulty temp sensor that works fine at 20C and 100C but not at 220C. I created this short video to help you test your temp sensor without needing any equipment:

Cold pull is very simple. Heat head to 180C or warmer and push in the PLA until a little is coming out the nozzle. Then let it cool to 90C (130C for ABS). Then pull hard back at the feeder. Maybe 10kg of force. If you need more force it's too cold. If you need less than 1KG force it was too hot. Here are 4 successive cold pulls - the first one was slightly too warm but good enough:

My fine is basically silent. Someone else came over to my house and didn't believe me when I said it was on. He had to touch it. He has an UM2 and his is louder. If I turn off everything in the house (televisions, fans, dishwasher) and no cars are driving by outside and if I close all the windows (noisy birds and insects!) I can hear it from about 3 feet away. Any farther and the blood going through my ears drowns out the noise. So... If you can hear the fan at all then I consider it defective. We are talking about the "third fan". Behind the print head. I recommend buying another one. Or remove the decal and add a drop of oil (I've done this to other fans but don't know if this trick works with this fan).

Many many people have underextrusion just like this. It is amazing how many things people try that actually fix the problem. I wish I could say there is only one problem and one fix. Just today someone put the filament on the floor and that fixed all their problems! Because the filament entered the extruder straight. That's my fix by the way. The most common problem for new printers is the temperature sensor seems to be off such that the print head is too cold. For older printers like yours the most common problem seems to be the isolator. Fortunately 90% of the printers out there are fine. Clogged nozzles are also common. You can remove the nozzle and put the entire thing in a flame to carbonize anything left in there.

If you don't care how pretty the parts are you can print them quite fast. The best method whether you print fast or slow is to print it once and then measure all the errors and then adjust your CAD model by those amounts. For example all your vertical holes will be around .5mm too small in diameter but your outside surfaces will be only shrunk by around .3%. Horizontal holes will be almost perfect. Bottom layers might exhibit swelling inwards or outwards depending on heat bed temperature and height from heated bed and fan speed for a given layer. All of these can be compensated for in CAD such that you get a perfect part. Usually if a part has 50 dimensions only 5 or so are critical for fitting with other parts. However if you change your print speed, bed temp, fan speeds, nozzle temp the part might change a little bit. Even if you change printers. This may sound like a pain in the neck but usually I only have to print a few layers to get a measurement as the Z dimensions are always the most accurate.

I think it's going clockwise around the cylindrical part some times and counter clockwise other times. Combine that with high print speed changes where the nozzle pressures vary greatly and you get this pattern. You might be able to reduce this if you reduce the polygon count around the cylinder. Marlin can only look 20 or so line segments ahead and if you have 20 line segments in that cylindrical portion it has to slow down a lot (be ready to stop because it doesn't know what's coming up and there might be a sharp corner coming up and not just this smooth curve). You can almost surely fix this by printing at the jerk value which is 20mm/sec. That way the printer will not speed up or slow down at these spots. Or you can get it close enough at 35mm/sec to greatly reduce this. 1) What speed where you printing at? 2) How many line segments are in each of those curved areas? (try to keep it under 10 line segments) In other words, for a given slice, how many polygons does the printer head pass across? What CAD software did you use? Some of these have settings when you save the STL (e.g. solidworks or DSM), other's have settings when you create the Curve (e.g. sketchup).

Regarding makerbots - everyone who I've talked to and has one and also a UM (I've met maybe 20 people who have both) hate the makerbot compared to the UM. They say the quality is much worse and it keeps breaking and currently doesn't work at all but their UM is working great. 100% of the people who have both have told me this. Of course someone will now probably post below saying their makerbot is better and works fine, lol. Also I am told that their customer support is completely backed up for months now. I totally agree with your perception about people buying UMO versus UM2 and makerbot. Part of the problem is the phrase "3D printing" which people and the press make it sound as simple as 2D printing. It should be called "additive manufacturing". 3D printing is just as difficult and complicated as using a milling machine yet my neighbors are much more scared of getting started on buying a milling machine. Isolator UM has improved the teflon isolator so that it will last longer and they are working on an all metal head I believe. Unfortunately that might be the UM3. Atomic Method (aka cold pull) I now do this on EVERY filament change. In fact I don't use the menu to change filament anymore. At the end of every print I set the temp to 90C and push the filament in a bit while cooling (unless I know for sure I'm printing again with the same color) and when it gets to 90C I pull the filament out the back. After it is almost to the feeder I let it cool another 20 seconds then pull fast and hard so a piece doesn't break off in the feeder. I then cut off the tip of the filament (two cuts at different angle to make a point) before storing the filament. When I change colors I no longer have to wait to get all the old plastic out.