thefordprefect

I've been thinking of this too. Surely the best way would be to use an optical mouse - greater accuracy, no contact, very small sense area - could be used on print head. trouble is you really need to know the filament pressure as well as if it is actually moving.

printing test piece at 260°C material ABS clear 3mm 3D Filaprint UM2 unmodified bed temperature 80°C Note that 3 and 4 mm^3/s are transluscent 5 and above just about transparent filament feed 117% with diameter of filament set in UM to 3mm

thanks for the info no response from ultimaker yet so purchased from farnell (min order £20 so bought more stuff1) fitted by first placing thin layer of thermal grease (leftover from cpu heatsink). ensuring one pad left free of grease. pushed sensor onto grease and soldered one end. solder thin wire from other end of sensor to pin of connector. Hopefully his will stop differential thermal expansion from causing further problems. blurred and messy photo:

When printing at 100mm/s long items oriented front to back the print head touches a small printed lump above normal height the plate resonates. This can be fixed by slow printing but 100mm/s usually prints ok The initial oscillation obviosly causes further z axis height differences which the head then touches and this prolongs the oscillation. Eventually long sections of print get wavy. this is a video at 240 frames/sec of the problem (printing at about 100mm/s) www.youtube.com/embed/1GqTaTMnr6Y the finished print looks like this: Is there any simple cure for this other than printing b

Just typed loads in then lost it all so this will be brief: Same error message, tracked down to resistive connection of the thermistor element - white square to right of screw terminals (strange place to measure temperature!) in picture below- resistance changes wildly with multimeter connected to pads of thermistor. Placing a ceramic part on a baseplate with little mechanical compliance cannot be wise unless the thermal expansions are matched. This would be made worse if lead (Pb) free solder is used. better use thin wires to pads from sensor then mount the sensor on the base plate using

UM2 Firstly do not enable cooling fans! Unless well away from the area that is likely to lift. Use 85-90C hot bed do not cool at any print level I had long piece (just fits diagonally) with fans the end lifted and even material delaminated. With no cooling fans managed to print ok. The piece had reasonable contact area so no point with raft skirt is one thin layer and no way will hold down material once it starts to cool (see bed levelling below). If you print a long tall item then put a 2 to 3 layer lily pad at the ends - needed this to print a star the points (little surface contact