I would like to move a 3m horizontal beam up & down so it remains horizontal always.
I thought to use 2 electric motors & a single simple motor controller but I think the motors will not stay in
sync close enough to achieve this.
Is there a better way? & where to start
What type of motor?
a 3 METER bar is quite big, and probably heavy. I suspect you’ll be wanting two different drivers.
In principle, two of the same type of stepper motor in full-step mode can be quite good at staying in sync. That is because as long as one doesn’t stall because of a greater load, they make discrete steps. But they’re also typically not so efficient or powerful compared to geared DC motors. So if the 3M part is anything heavy, I don’t think you’ll be using steppers.
But I assume with such a large bar, you will be using higher powered DC or BLDC motors. You will probably want two different drivers. But if you device your mechanism in such a way that the motor which needs to “speed up” is under reduced load whenever it needs to “catch up” to its partner, than a DC motor might work well. The motor when unloaded will speed up, so it will always catch up. So you could probably run it off of one driver in that case. But many lifting mechanisms would not necessarily bias the system in this way, and in fact would do the opposite.