I Need a Solid Ball

Canon ball comes to mind. . .

. . . not a game though and not played with "balls" anymore . . .

croquet ball size is 3.625 inches

smaller then wanted

ignator

Doesn't the fishing/sailing industry used large wooden ball floats?

You might try a search for something like that.

And, we have a winner!

My thought was to have a machine shop with a machining center make one. Easy peasy for them.

This looks cheaper.

Depends how round it needs to be, but good, simple solution.

Yeah, I'll bet there will be a tendency to oblate a bit as it hardens. Depends on the filler and the ball composition.

Maybe float the thing in water, keep it spinning until it skins/crusts over.

[edit] This is probably a lot of dinkin around for a POC prototype. Like you, I'm liking the wood ball idea more and more.

Set it in a bucket and mostly surround it with damp sand before trying to fill it. Maybe fill it with a mix of epoxy and sawdust.

Meets all requirements of the OP. Our work here is done.

If you decide to mold it rather than use the wooden one you might consider polymorph plastic:-

http://www.google.co.uk/#sclient=psy-ab&hl=en&safe=active&tbo=d&q=polymorph+plastic+USA&oq=polymorph+plastic+USA&gs_l=hp.3..33i38.10641.12922.2.15187.4.4.0.0.0.0.282.938.0j1j3.4.0.les%3B..0.0...1c.1.2.hp.nMEj5MZs4z8&pbx=1&bav=on.2,or.r_gc.r_pw.&bvm=bv.42261806,d.d2k&fp=7a6c665d2c67ce29&biw=1366&bih=874

Everyone - THANK YOU! Great resources. USBPort, I somehow missed the wood balls in my search, I think I was looking for stuff that was too industrial. Turns out I have a woodworker right across the street from me. And Ozzb, I might find one of those duck pin balls. Something right btw 4 and 6 inches might be best. Kramarat, thanks for the link to Rochester Makerspace. Right in my own backyard and I had not heard of them. I will check them out. I have clients that would like to know about them as well. Doorman, I was thinking about those vinyl balls just yesterday - I have a couple that I hold in my hands while doing pushups. Afraid the cheap ones I have aren't round enough, but a better quality ball might work.

Thanks again all, I have some GAs to do now.

jhammond

Five pin bowling in Canada uses balls ranging in size from 4 1/2" to 5". There were two new ones posted on Kijiji (like a Craigslist) in Ontario for $90.00. I have seen them as low as $10.00 at garage sales.

Vic

Bocce Balls are made of wood or plastic and are 4.2" in diameter and weigh 2 lbs. If you want something absolute you may want to get a 3d printing company to make what you need.

Thanks, Byron, I will check out bocce. The bocce balls I found online were smaller. I've only played once about 30 years ago and had no recollection of a ball > 4inches.

jhammond

Could you describe the other design requirements such as min/max weight, temperature range in operation, hardness, both surface and internal, even material characteristics throughout the ball, and true dimensional roundness? Some molded plastics may be useful, but will require a compromise to some of the above characteristics. And true roundness may require some delicate secondary machining. The ball valve is a great idea and I have used it myself for some of my projects but nothing that large in diameter.

OldTooly, I haven't worked out all of the specs yet, so I can only guess right now. At this point, this is to be a rough prototype to just prove out the overall concept, that it hopefully works as expected.

It is a consumer product, so shelf price is going to be important. An inexpensive molded hard plastic will probably work. No need for varied composition, can be homogeneous throughout. No need for any special surface texture although a couple of features can be molded in. Just a guess, but a 6" version would probably have to be within 0.05" of true roundness. Maybe less. I don't think that's hard to do with a mold.

For now, using a wood ball, duck pin, or bocce ball as suggested here for my rough prototype will work fine.

jhammond

We make metal balls,both solid and hollow.the ball is used in ball valves.If you have drawing for your balls, I will check what I can do for you.

did0407,

Thank you for your kind offer. I have looked at your website, and it looks like you have good ball manufacturing. But I do not yet have any drawings of my balls. I have purchased a solid wood ball from the vendor recommended by USBPort in post number 6 above for prototyping purposes. I will first build a prototype of my invention to see if it works. If I am successful, I will make a drawing and contact you to see if your firm might be able to make my balls for me. Thank you again.

jhammond