RC stage pieces

[GreekTheatre]

I've read a couple of posts about people trying and failing with remote control cars and stage pieces. I've also read about someone using an old power chair for moving a piece. I've checked out a few remote controlled platform products such as Turtle.

I want to do remote controlled and the piece needs to support about 350lb. Before I go with the Turtle product, I'd like your opinion if this plan is worth trying:

The idea is for the Cat in the Hat's car. I get three remote control monster trucks. One would go in the front and would be the only one to do any steering. The two in back would be for support and extra motor power.

 

[porkchop]

I don't think adding RC monster trucks would be your best solution. I also have some serious doubt in their ability to keep traction while trying to move 350 lbs.

What I would do is build two motors into the prop that are powerful enough to drive it, get a board capable of driving them, and then find a wireless solution that integrates with that board. I say two motors because if you have the back wheels powered you can have the front wheels just be swivel castors and use forklift style steering.

These motors are 2/3 hp 24V motors with a mounting bracket and a gear box that reduces down to 500RPM max speed for $120 each: https://www.motiondynamics.com.au/dayton-500w-0.67-hp-24v-dc-planetary-500rpm.html

Here is an Arduino compatible motor controller board that can run them for $70: https://www.pololu.com/product/2518

Because the controller is an Arduino compatible form factor you can choose any wireless protocol you want really, but XBee is pretty well documented all over so that's what I would go with. You could pair it with a joystick like controller on the other side for manual control or try to integrate a preprogrammed sequence. Arduinos, shields, XBee transmitters, and bits probably run another $200-$300 but then you're pretty close to done and you have a wireless system built on flexible parts that could be recycled into future shows.

Two 2/3 hp motors might be a bit much but there are a lot of hard to measure factors that go into how much force is required to move a rolling object. 500RPM is probably faster than needed so an extra 2:1 gear reduction might help things as well.

 

[Dover]

Not to be a wet blanket but I think this is intended to be a human occupied prop. I am a little iffy on the safety of a home brew controller on a 500+lb moving prop with an actor in it.

 

[GreekTheatre]

Sorry, I could've included that before. Yes, this is human occupied (two person). Thanks, porkchop for your advice and helpful links to possible products. I really appreicate it!

 

[Amiers]

If it’s a driven prop then I suggest you rent or ask a local golf car shop for an electric cart. Then build your frame around it. There are enough bolts that can support anything you put on it.

 

[Crisp image]

I have done the RC thing on stage with people on it.I used 2 powerchair motors mid mounted and a sabretooth motor controller and an RC transmitter. If you build it with limit switches so if if gets too close to the edge of the stage it stops and cant fall off the stage. I use Lipo batteries because they are high discharge and quick charging and usually do not need to be used for long. Powerchairs can move 150kg plus the weight of the chair so that would be close to 250kg (or about 500lb).
Look around and you may find a powerchair for free (I have had 2 chairs and one scooter). I have the control units for them too but they are 24v and I find that 12v or 16v is plenty of power to run the motors for what I want.
By mid mounting the motors the item can spin on the spot by reversing one motor and still having one going forward. The motor controller can be set up so that it is all on one stick so pushing forward moves both motors forward and lever backwards moves backwards. If you go left or right it turns one motor fwd and one bwd so it turns on the spot. A little left or right going forward gives radius turns.
Good fun to drive. I had my daughter on a device that was 700mm diameter and 600mm high and she was strapped in for Froma Sarah in "Fidler on the roof" and was hands free. I have done a bed for Addams Family and also a moon chair for Addams. My next trick is a magic carpet for Aladin Jr. This will not only move about the stage bu rise and fall from 300mm to 750mm. This is to be achieved using a hospital bed frame that raises and lowers with 2 motor controllers (one for drive and one for raising).

If you have any questions yell out.
Regards
Geoff

 

[RonHebbard]

I have done the RC thing on stage with people on it.I used 2 powerchair motors mid mounted and a sabretooth motor controller and an RC transmitter. If you build it with limit switches so if if gets too close to the edge of the stage it stops and cant fall off the stage. I use Lipo batteries because they are high discharge and quick charging and usually do not need to be used for long. Powerchairs can move 150kg plus the weight of the chair so that would be close to 250kg (or about 500lb).
Look around and you may find a powerchair for free (I have had 2 chairs and one scooter). I have the control units for them too but they are 24v and I find that 12v or 16v is plenty of power to run the motors for what I want.
By mid mounting the motors the item can spin on the spot by reversing one motor and still having one going forward. The motor controller can be set up so that it is all on one stick so pushing forward moves both motors forward and lever backwards moves backwards. If you go left or right it turns one motor fwd and one bwd so it turns on the spot. A little left or right going forward gives radius turns.
Good fun to drive. I had my daughter on a device that was 700mm diameter and 600mm high and she was strapped in for Froma Sarah in "Fidler on the roof" and was hands free. I have done a bed for Addams Family and also a moon chair for Addams. My next trick is a magic carpet for Aladin Jr. This will not only move about the stage bu rise and fall from 300mm to 750mm. This is to be achieved using a hospital bed frame that raises and lowers with 2 motor controllers (one for drive and one for raising).

If you have any questions yell out.
Regards
Geoff

@Crisp image When my Mom was 94 and hopelessly crippled with arthritis I got her a power chair as you describe which included a worm driven vertical lift function all operated by the same joy-stick controller. I've forgotten how but some combination of movements switched the controller from drive: forward, reverse, left, right, rotate into maintain position and raise, lower. Occasionally, she'd be dining at a table with three mates and her controller would be out of sight below the table, she'd inadvertently get it shifted from drive to lift, attempt to back up and begin lifting , tilting the table MUCH to her startled mate's surprise. I eventually solved the problem by unplugging the lift motor and ty-wrapping the female connector next to its mate for the convenience of future owners. As you posted, a little Googling ought to turn up a service club or two happy to provide power-chairs and hospital beds for free or very little cost. I'm posting from Canada but I found a service club within 30 miles who were delighted to fetch both my Mom's power chair along with one belonging to one of her sisters.
Guard your health.
Toodleoo!
Ron Hebbard

 

[Van]

It's the RC part that bothers me. I built the row boat for "Jack Goes Boating" from power chair parts. Mounted the drive wheels mid boat and put two swivel caster underneath the rear set of the boat. The Actress that say in the rear of the boat actually drove the boat as 'Jack' was busy rowing. I worked flawlessly, every time. Remote control, especially if you are on a proscenium or any raised platform stage concerns me. the Actors need to have a dead man at least.
If you were to go with RC i'd strongly look into a digitally secured control system so you don't run the risk of interference to your control signal.

 

[SHCP]

I have a power chair unit that has been in several shows. It's been a car, Hortons tree, a rowboat, a double bed, you name it. Find a motorized wheel chair or similar on craigslist.

 

[icewolf08]

If there is an actor in it, why does it have to be RC? Let the actor drive it. We did this for a production of Sunset Boulevard, where we attached a battery powered electric motor and drive wheel to a real antique car. We gave the actor a speed controller and they used the car's actual steering rack to steer. Worked fine, although it was a PITA to maneuver backstage just for the one scene it was used in. Ultimately if you were thinking you would build something yourself from scratch, it may be just as cost effective to get an old golf cart and use the chassis, then you don't have to figure out how to steer and what not.

Of course, you could also just go the fully automated route, put a track in the deck, drop a knife from the vehicle, attache to cable and winch, and pull the thing across the stage.