carl_m1968 wrote:grob wrote:Are you sure the screw is that small? I'm pretty sure the extruder gear and pulleys on my solidoodle are M3's (which incidentally use a 1.5mm hex key).
(see here, note dimension 'j')
..image..
I have the same machine just the metal version. They are a 2mm screw and require a 1.5mm hex key. I just measured mine since I was moving my defective extruders nozzle up for know.
Not to doubt your measurements, but if you're right then you have a completely unique set screw, which seems like a terrible waste of time and money on the part of CTC.
1.5mm hex just doesn't fit onto a 2mm set screw (the hex corner-to-corner is larger than the thread's minor diameter). Please check both those numbers? I really don't want to see the OP get sent off to special order a freaky microscopic set screw when they could have bought something in a hobby shop... 
SD3. Mk2b + glass, heated enclosure, GT2 belts, direct drive y shaft, linear bearings, bowden-feed E3D v5 w/ 0.9° stepper
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