First, I just want to apologize if this isn't the correct forum. If a mod needs to move it, my mistake.

I'm trying to find explosion proof motors for an automated panel painting rig. Given the fairly light weight of an automatic spray gun which seem to max out at about 1.5lbs regardless of HVLP, airless, or conventional, I don't need particularly powerful motors. Counting the spray gun, the weight of any paint in the lines, and the armature the gun will be mounted to, I'm looking at 12lbs or less to actually lift vertically. The whole rig will have a vertical orientation and I don't anticipate adding an in/out movement at any point down the line.

Working from the driving torque calculations I've found, moving such a small weight, even doubling the load to account for any friction from the guide rails (using UHMW PE slides from 8020) or from a ball screw wiper, I'm still coming out to about 3in*lb of needed driving torque. That number seems low, but it's a really small weight. I also don't need to go spectacularly fast. 500rpm is more than enough.

I haven't found much in terms of explosion proof servos or steppers at all. The limited pricing information I've been able to gather starts at $3k/ea, and are a solid order of magnitude more power than I'm going to need. Given my torque and speed requirements, it looks like like less than 25W continuous power.

I'm open to using any kind of motor, servo, stepper, or somethign else altogether. I'm interested in servos just because of the inherent feedback mechanism, but I'm open to any ideas. I've even looked at pneumatic motors, but the only ones I've been able to find seem to be all designed for either incredibly high speeds, like the actual chuck of a mill, or for continuous operation. But if you know of a pneumatic motor that can give some precision, I'm definitely willing to check it out.

If anyone thinks I've done some of my math wrong, I'm open to any pointers in recalculating my values.

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