I assembled it and connected to a stepper driver.  While it was running I attempted to prevent rotation by holding a pair of 40 tooth pulleys with my hands.  I couldn't stop it.  This thing will be able to lift a decent amount of weight.  

I was thinking of building a structure to test it, but after looking at options, decided the easiest thing to do would be to pull the Rino out of UMMD and replace it with this gearbox.  When it finishes printing (rev 3, now), I'll install it in UMMD and run some tests.  UMMD currently uses HTD-3M belts - I'll be replacing them with GT2.

Planned tests include lifting capacity, precision and accuracy tests to be made by bolting a gauge to the printer's frame and letting the bed bump the probe.  I'll also run some speed tests.  At 40:1 the maximum speed may be less than the Rino's 20 mm/sec.