Tuesday, July 24, 2007
I've included a GM9 at the right of the pic. It is very like the one Darwin uses on the Mk II extruder though with a different gear ratio. Above and to the left of it is the GM-17 which I plan to use on the Mk 2 AEM extruder that I am presently designing.
I took a few moments and ran the GM-17 at 5 and 9 volts. That thing has HUGE torque. I couldn't stall the drive shaft with my fingers running it at 1.5 volts. I think that it is going to work just fine for pumping HPP and ABS. Dan was right. The mounting holes for the GM-17 are both further apart and at the other end of the gearmotor from the GM-3.
The tiny little pair of motors with brass gearboxes are GM-11a. Those are expensive little mites at $16.80 each. The trick is that they deliver 7.5 oz-in of torque and, I think, will drive the Tommelise xy positioning stage on a diagonal at about 6 mm/sec. As well, these tiny little motors, unlike the ones I am using now, are almost impossible to hear from a few feet away. This is a great idea if a kid decides to print something overnight in his bedroom.
One thing, though. The coupling is slightly smaller than the one we are currently using.
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