Putting a car on casters

[Tex]

I found a car to use for Greased Lightning in Grease. It's a 1940 Pontiac with no engine, transmission or interior so it's about as light as it's going to get. Here's a pic:

I want to build a wagon unit for each axle. I'm thinking about using 4x6 and bolting it together with very long carriage bolts or allthread, then using 4 castors on each unit.
I'll get good estimate of the weight when the guy calls me back, but I'm thinking about 2500 pounds. How would I go about deciding what castors to use? Is there a formula to give me an idea of how much weight each castor will be supporting if there are eight total? Any other ideas? I really think it needs to move like a wagon and not like a car to make it easier to get around back stage.
Edit: I found a formula. Load capacity of castor = Weight of equipment + trolley ÷ 3
So, if my total load is 4000 lbs. these castors should be sufficient overkill, no? http://www.grainger.com/Grainger/Swivel-Caster-1NUY7?Pid=search

 

[DrPinto]

Just be sure the instrument cluster with the speedometer and gauges has been removed. In cars from that era, manufacturers used radioactive radium on gauges to make them glow so you could see them at night. This was also commonly done on clock faces and aircraft instruments. You don't want this to become an issue.

Radium dials - Wikipedia, the free encyclopedia
Radium Watch Hands - YouTube

FYI, an interesting story on the girls who painted the radium is on YouTube:

RADIUM CITY 1987 Complete 102 min. Feature Documentary Film - YouTube

 

[derekleffew]

And an appropriate for high school play, Radium Girls .

Tex, I'd use a variant of triple swivel caster/turtle/zero throw caster.

EDIT: BTW, it's "caster." Castor is either a star or a figure from Greek mythology. Don't use Castor oil on your casters.

 

[Van]

Are you going to install the "trolley" in the tire with a cut out in it ? or are you going to build a wagon that the entire frame sits on ? Just wondering. I secon Derek, a zero throw will be a must. and you want to instruct the kids that even though it's not a running car it's still 2500 pounds. As my boss in college would tell the Beauty Paegent contestants, " Girls this is a 2,000 pound piano, if it hits you, it'll kill you!"

While I appreciate Dr.Pinto's interest in safety, I'd have to say that the amount of radiation one is recieveing from Fukishima Daiichi right now FAR outweighs the amount you or your students will recieve from a gauge cluster.

 

[Tex]

And an appropriate for high school play, Radium Girls .

Tex, I'd use a variant of triple swivel caster/turtle/zero throw caster.

Thanks for the castor recommendation Derek. As for Radium Girls; WAAAY overdone.

 

[Tex]

Are you going to install the "trolley" in the tire with a cut out in it ? or are you going to build a wagon that the entire frame sits on ? Just wondering.

Well, now I'm wondering too. I thought I was going to do 2 wagons; one for each axle, but you've made me think. Thanks!

 

[techieman33]

Why make something when you can buy them pretty cheaply. You could even sell them on craigslist when your down, or even return them if it's a short run.

Vehicle Dollies - 2 Piece, 1000 Lb. Capacity

 

[derekleffew]

Good thought, but

1. I wouldn't want an all-steel caster on my wood/masonite surfaced stage.
2. I'd want to hide the dolly(s) so connecting to the axles or frame inboard of each tire would be preferred.

 

[65535]

First off you need to be using the proper load requirements to decide what casters you need.

In the off chance your load is perfectly balanced you would take the total load and divide it by the number of supports, casters in this case.

Since it's probably a bit off of balanced you'll want to factor in a certain amount of headroom for each caster.

The other thing to consider is that if it is 2500# or more you'll certainly need more than just a pair of standard framed platforms to support it. I highly doubt that you can just set it flat onto platforms and balance it. most cars aren't perfectly flat on the bottom frame, which is likely a problem.

If it were me I would plan on building a sub frame of wood (steel if you have a welding shop) mounting 4 casters of sufficient strength (the zero throw casters are the bees knees) in each corner and then placing the vehicle on it using strategic points to support the weight.

Now you have to figure out how to lift a car straight up to set it on this rig.

 

[Tex]

If it were me I would plan on building a sub frame of wood (steel if you have a welding shop) mounting 4 casters of sufficient strength (the zero throw casters are the bees knees) in each corner and then placing the vehicle on it using strategic points to support the weight.

Now you have to figure out how to lift a car straight up to set it on this rig.

I'm building a sub frame of 4x6 with no top and will notch it if needed to fit the underside of the car. With no drive train or transmission, it's easier to make it work. I've used a car before where this was done and actually had to do some repairs on it to make it work. It will be heavy, but I'm using at least 8, 1200 lb. casters so I think I'm OK on the load.
I took the wagons off the car I used before. It's not really about lifting the car straight up; it's about lowering it straight down.

 

[Jackalope]

Would it be easier to build the frame and bolt it to the car with plates built into the frame to accept the castors... then you could jack up each corner of the vehicle, mount a plate, lower and repeat x4