[SML] Variable speed motor

[Brian Munroe]

"Or you can just 'borrow' the winch in your gym built to pivot a basketball hoop out of the way, or the winch used to pull a Pleasure Craft on to it's trailer."

You COULD but that's probably not a very good idea. Probably fixed speed with no accel or decel and certainly no emergency stop loop in case something goes south. 

Brian Munroe

Sent from my iThingy. Please excuse any typos

> On May 11, 2016, at 12:58 PM, Richard Niederberg via Stagecraft <stagecraft at theatrical.net> wrote:
> 
> Or you can just 'borrow' the winch in your gym built to pivot a basketball hoop out of the way, or the winch used to pull a Pleasure Craft on to it's trailer.
> /s/ Richard
> _________
> 
>> On Wed, May 11, 2016 at 9:14 AM, Loren Schreiber via Stagecraft <stagecraft at theatrical.net> wrote:
>> AC motors have pretty much supplanted DC motors in most industries. The cost of AC inverters (drives) has come down to the point that AC is actually a much more economical way to go.
>> 
>> In this case, it's not a simple matter of buying a variable speed motor. All commonly available motors (AC or DC) will need a gear box of some sort to drop the speed and increase the torque to something you can use. But that's not the end of it. If you are connecting a cable to this motor, then you will need a drum of some sort and the support structure (winch) to go with it. As others have mentioned, then there is electrical cabling ($$), controls, e-stop circuits, electrical enclosures etc., etc., etc. All this is fun stuff to design and build, but it sounds like you are on a tight schedule and a little behind the curve for developing your own system in house.
>> 
>> Others have mentioned Creative Conners as a source for a turn-key system that you can buy off the shelf. I heartily concur. However, a glance at the prices (and Creative Conners is very affordable when compared to other available systems) and I think, in this case anyway, you might just want to pull a rope. I have designed and built automated scenery movers for decades now, but these days it's just easier, cheaper and faster to buy a system like Creative Conners.
>> 
>> OK, that said, I know of a school that will rent a compact hand-cranked winch that would likely work in your situation. Most of your cost would be shipping to and from your theatre because winches are heavy. Let me know and I will put you in touch.
>> 
>> Loren Schreiber, Professor Emeritus
>> San Diego State University
>> 
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> 
> 
> 
> -- 
> /s/ Richard
> _________
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