Bit of an update:

It took about three evenings to assemble about 500 parts. Some minor niggles with the assembly such as wrong size screws specified in places, square nuts used for assembling the laser cut acrylic frame too wide to fit some of the slots in the frame. The round rails for the x-axis wouldn't fit in the holes in the metal end brackets which had to be opened out with a rat-tail file. Nothing too taxing to correct.

So, with the build complete I installed the Linux version of the Repetier software on my laptop to drive it. Firing up the software it found the printer and connected so I tried manual control to jog all the axes but one of the two z-axis motors didn't work. I tried plugging it into a different driver but still no joy. I then noticed that two of the wires in the lead connecting that motor to the driver were swapped over compared to the other motor leads, cut the leads and cross wired them and the motor the worked!

Tried homing all axes and found that the x-axis motor drove the carriage in the wrong direction, away from the home switch. A quick check on the Geetech forum and it appears that the supplied firmware for the control board has the x-axis direction wrong and you need to modify a setting the firmware. I already have the Arduino IDE installed so I modified the firmware accordingly and uploaded it to the Arduino based control board.

All then seemed OK so I levelled the bed, set the nozzle height using a paper feeler, anddrew up a 25 mm cube and opened the file in Repetier. Sliced it using Slic3r and previewed it. It looked O.K. so I tried to thread some filament into the extruder to print it. B****r it! It wouldn't go in more than halfway to the nozzle.

After calming down, the next day I stripped the extruder and found that the throat piece that guides the filament into the nozzle had a sharp step in its bore about 6 or 7 mm down and the filament was catching on that. I thought there might be a bush missing but eventually decided to just chamfer the step using a 3 mm spotting drill. Reassembled the extruder and found it easy to thread.

So, tried to print my test cube again. Not very successful – despite careful setting of the nozzle height it tried to print the first layer 2 mm above the bed.

Back to the forum and I found that there has been an ongoing problem with the z-axis homing with no real answer. I tried homing the printer again and found that homing it by pressing the home button on the manual interface on Repetier homed it correctly to the switch closing position but homing it from Gcode it went to the switch closed position but lifted by 2 mm before zeroing the z-axis.

After spending some time poring over the firmware files I found a setting that seemed wrong, changed it, recompiled and uploaded the firmware and tried again and it printed correctly.

The result was better than I expected for a first try. The cube measures between 0.15 and 0.22 mm undersize – good enough for now while I play with the various parameters to get the best performance.

Next I'd better make something useful on it for her indoors to justify the time and cost. Although I think the cost was well worth it for the learning experience alone.

Russell;

P.S. If anyone else is tempted to buy one I'll supply details of the firmware mods needed.