Moved: how to go about making a large sphere

[Firefoxm31]

Howdy gang,
I moved my thread to this area as it seemed more appropriate as to what the final item will be. I need to make a sphere of 36" diameter, it's sort of dome shaped anyway, with additional dome shaped cutouts. I'm looking for thoughts on the cheapest way of doing this. I thought of taking a length of steel rod and making a sleeve that will spin around it. On this sleeve would be welded a cutting template. I would glue blue or pink foam in the middle of this rod, rough it to sphere shape and then use the free spining cutting template on either side of the rod to Turn the foam to shape and then screed the semi-final finish( body filler), see illistration. Does anyone here have any other ideas to make this detail as cheaply and quickly as possible? thoughts,?

Cheers,
Will

 

[Zombie Killer]

I'm going to be ordering 2 36" domes from these guys in the next month for a Tie fuselage display for my SSC Vader bust. Not sure how much you want to spend.

http://www.cleardomes.com/domes.htm

 

[Firefoxm31]

Hi there, thanks for that...We used "clear domes" when restoring the Nautilus for Disney, so I'm very familiar with them. Since I have to cut certain shapes into the sphere anyway, It doesnt' look like a viable option, although... maybe as a last resort, a half sphere and fill with expanding foam, make two and continue on this project. Ya know, the sad thing is, I have a styrofoam place not 500 yards from my house that does architectual foam, they can do me a sphere, but want 342.00 for it, granted, that's 100.00 cheaper than anyone else I called. As you can see by this photo, I'll need to cut yet another dome shape out of the sphere on both sides.. so, any other viable solutions, cheaper the better.
Will

 

[clonesix]

If you used the acrylic hemisphere as a mold and pour something into it for your shpere, you could return the sacrylic one for you don't need it any more.

 

[Firefoxm31]

If you used the acrylic hemisphere as a mold and pour something into it for your shpere, you could return the sacrylic one for you don't need it any more.

LOL, I doubt I could get away with that...but lol, that's a cheap way of doing it for sure.

So, has anyone ever lathed their own dome? If I do go this route, I will turn all necessary additional cuts necessary to speed up the build process.

In case you are wondering, the project is a full size 1980's version Lightcycle replica.

Will

 

[Zombie Killer]

For $350 you can get 2 acryllic domes and you wouldn't have to mess with the foam. Glue the 2 together, cut 2 ends and flip them around and glue them in. Or do it with 1 dome make a plaster mold and cast some fiberglass halves. In the end it's a pay me now or pay me later scenario. Do you plan on sitting on the bike? If so i don't think either will be strong enough. Well the fiberglass method would be if you make it thick enough.

Just some thoughts.

 

[Firefoxm31]

thank you for your thoughts. Yes, I was thinking about getting a dome and making a casting out of it to get my masters, I think Fiberglass will be the end result on this no matter what. I will be able to fit inside the bike "cowl" just like the original.. full size replica. the only problem with using the end caps of the dome is that the radius(depth)will be too shallow.
Will

 

[ave4uevoli]

what do you need this made of?

the cheapest way possible I can think of is buy a 36" toy ball at the supermarket. Many supermarkets have those giant wire bins filled with those big balls.

so take it and pour resin all over it. A little bit of sanding at the overpour areas should take care of any issues.

It'll be messy...

a less cheap way is to make a silicone mold of the ball and then pour resin into it. That of course is not messy - but you have to pay for a lot of silicone

 

[Firefoxm31]

Howdy,
I wanted to go something simular to this route so had purchased an exercise ball. It's not large enough in diameter, right around 30", I need a 36" diameter in order to fit inside the replica. If I could find a toy ball at 36" I would snap it up in a heart beat. I can make whatever molds I need for the master pattern, but have had no luck finding a ball large enough. bummer!
any sources for large balls 36" diameter???, maybe I missed something in my search...
Cheers,
Will

 

[ave4uevoli]

inflatable balls

plenty of them everywhere.


http://www.ameripromo.com/inflatable-soccer-ball-p-6928.html?affiliate_banner_id=3&ref=2

 

[Firefoxm31]

aha , now we're getting somewhere...guess they are closed .... drats! ohh well, I just sent for a sample.. I'll see if that works

Will

 

[vampire knight]

Even cheaper would be a balloon

http://bayareaballoons.net/product.sc?productId=171&categoryId=4

I had an aunt that used to build replica costumes, like the Disney theme park ones. She'd use a big balloon those that you used to be able to buy at a supermarket or drugs store that you can blow up huge and tie a rubber band around the knot so you could bang it off your fist (does that make sense?). Well then she'd cover it with paper mache pop the balloon and she'd have a nice big sphere.

I'm thinking paper mache may not work for you, but maybe as someone suggested cover it in resin or something. Or maybe do paper mache at first and cover that with resin and fiberglass. You can't get cheaper than a balloon that costs a few bucks and paper mache is pretty much free if you have old newspaper and some flour and water.

 

[drusselmeyer]

Technically, what you need is a Cage Ball. They are commonly 36".

Shop for sales.

BTW, shouldn't this be in another forum?

 

[Firefoxm31]

nope,
It's in the right forum according to what I read on the Sticky about what belongs here, full size prop or replica there of
Will

 

[Firefoxm31]

Update...
36" beachball on the way, a Free Sample!....that's pretty cheap, wonder if it can take the heat of the hydrocal

Will