If you search around a bit, you'll see where this has been discussed a few times before. But the short answer is yes, it is possible. The one thing you have to watch out for however, is when the motors power off, the gantry will fall/slam to the bottom, potentially causing damage.
thanks for reply, I found only one discussion but it barely gives an explanation for this issue. max torque of 17 NEMA stepper is 76oz/in (5.47kg/cm) so I guess I can lift ~11kg in the double motor axis. Two motor weight 0.7kg (each stepper motor weight 0.35kg) and V-Slot® 20x40 Linear Rail and plates weight ~1kg (my guess didn't see info) for 1500mm which leaves us with 1.7kg means we left with 9.3kg for the load. am I right?
Shachar, once the motors don't have power they are just free wheeling as the electric brake is not active. If you use lead screws this may not be a problem but if you use a belt system what romamaker said is true.
NB also keep in mind freewheeling stepper motors become generators that can easily kill stepper drivers. One will have to get into a strong habit of parking it in a "gravity proof" position before turning it off, or add some safety mechanisms like counterweights to stop it dropping down
thanks, I understand, so or I'll find a solution for safety (kind of stopper/spring) or maybe i'll try to use lead screws for the gravity axis. Is there any reference project which combine pulley-belt system to lead screw?
One suggestion would be mounting it with the X-axis vertical that way you only have to counter weight one actuator. A constant force spring would also be an option for that axis.
What Rick suggested is a good idea but then I would consider renaming the X and Y axes so that the 0,0 point will still be on the lower left corner. It may just make it oh so easy in the future having the 0 point in the conventional place.
