NON-PERSONNEL Elevator

[rbashley]

I'm working on building an elevator in a trap door that goes from the stage floor to the basement. THERE WILL NEVER BE ACTOR ON IT!! And I have steel braces when not in use just in case a tech walks on top of it. There is NO WAY for a tech to get under it while it's in use. The new problem is that the designer wants to put about 200# on it for the first act and nothing on it for the second (no intermission to remove counter weight). I would like to motorize it. Any suggestions on low budget motor controllers? I'm looking at a 5Hp or 10Hp DC motor so that I can use it to move wagons later.

[gafftaper]

TOS ruling from the Senior Team: It's okay to discuss motor control systems for elevators as long as discussion doesn't get into how to build the elevator itself. Stick to the OP's question and this thread will be allowed to continue. Drift into "how to build it land" and we will shut it down.

[fredthe]

Thanks Gaff, I was holding off for that very reason.

The question is, what's your definition of low budget? I found a controller on Tecknowledgey - Motor Controllers, DC Series (mainly intended for such applications as electric vehicles) thats only $160. Not sure you're going to get much cheaper than that. But you can easily get to the $500-$1000 range.

Are you running the motor from batteries? If so, don't forget you'll also need a way to charge them. I'm assuming that you just want something that will allow you to control speed and direction, if not, let us know.

-Fred

[Footer]

5hp or 10hp is way overkill for what you need. 1hp geared correctly would do what you need. I have lifted over 1000# onstage with 5hp.

Few questions... what kind of power do you have on your stage? Single phase 120v, 208v 3 phase, 240v three phase?

If you want to use an AC motor, you need to use a Varible Frequency Drive to control it. These can be picked up use, but even then it will cost you a few grand. Added to that you then need to control the VFD either using a PLC or limit switches (though limit switches should still be used with a PLC.

There really is no cheap way to do motion control onstage. Its going to cost you at least 5k, and even thats lowballing it.

Even after you get the motor you need to build a frame for it and mount it to a cable drum so you can use it to lift and pull. If you are going to use it for lifting you also have to install a brake. Its a lot more involved then just picking up a motor and bolting it in.

There are other options for you though. One is electric or pneumatic actuators. You might also want to look into using a chain motor instead of counterweights. There are a few other options as well, but let us know what you money situation really is and we can get that figured out.

[Traitor800]

If 200# is all your lifting I would go with an ATV or Jeep Winch. I has all the parts you need and it can either be run off of an old car battery or you can find 120vAC-12vDC transformer to run it. Northern Tool has some decent prices on electric winches.
-Chris

[icewolf08]

I don't know what your budget is, but I would look into the Make It Move system by Creative Conners Inc. They specialize in creating automation systems for budget minded theatres. They would be happy to offer you professional advice on your project and can sell or rent you the equipment you need to run it. We have been using their systems for many productions and it works great. It has been updated (control software and such) since the last time we used it, and we haven't tried the new version, but it looks nice.

[Footer]

Originally Posted by Traitor800

If 200# is all your lifting I would go with an ATV or Jeep Winch. I has all the parts you need and it can either be run off of an old car battery or you can find 120vAC-12vDC transformer to run it. Northern Tool has some decent prices on electric winches.
-Chris

NO. NO. NO.

NEVER USE AN OFF THE SHELF BUMPER WINCH TO LIFT ANYTHING.

Those winches are designed to PULL, not LIFT. What that means is they do not have the sufficient brake to hold the same amount they can lift. They are made to pull a jeep out of a ditch, and the worst that can happen is that the jeep falls back in the ditch if the winch fails. Chain Motors and winches designed for overhead lifting have brakes on them designed to stop 5x the load they can lift. You have to remember a winch moving 200# has to hold that 200# and deal with the forces exerted on the winch and cable when the load stops, otherwise known as a dynamic load. Truck winches are not designed to do that.

We used a creative connors winch this summer to fly our plane for The Drowsy Chaperon and it worked flawlessly. These motors are designed to do this type of thing. If you want to go with a turnkey solution, its the way to go. However, it will cost you about 2k for a 2 week rental.

No matter which way you cut it, there is no way to add vertical motion control onstage on the cheap, I don't care if you are lifting a feather or a house. Horizontal movement is a bit easier onstage because you don't have to deal with keeping the load up when you stop. With a vertical system this is the major issue.

[SHARYNF]

You just need to look outside of theatrical solutions a bit and you can find some reasonable solutions.

Here is a link to a DAVIT motor setup for lifiting a boat out of the water. Not all designs are just for pulling

Boat Lift Distributors : Hefty Hoist 3000 lb. Motor and Aluminum Gear Unit [AQUA3000] - $485.00

with a 3000 lb rating, and some work attaching the unit, this should be able to do the trick

Sharyn

[Footer]

Originally Posted by SHARYNF

You just need to look outside of theatrical solutions a bit and you can find some reasonable solutions.

Here is a link to a DAVIT motor setup for lifiting a boat out of the water. Not all designs are just for pulling

Boat Lift Distributors : Hefty Hoist 3000 lb. Motor and Aluminum Gear Unit [AQUA3000] - $485.00

with a 3000 lb rating, and some work attaching the unit, this should be able to do the trick

Sharyn

Keep in mind with that solution you still need to install hard limits and E-stop switches at various points on the stage. Also, it runs very slow, 2.5ft a minute.

[headcrab]

If you want to build the controller from scratch, or possibly the hardware, Automation Direct has nearly everything you need. They are aimed at the industrial automation market, but you should be able to get your stuff from them.