Aluminum Rola Bola Tube

[Evan Young]

This is a question about weights/strength.
I'm having an aluminum rola bola tube made for my "airplane" set of props.
I got a quote for a 9" Diameter, x 1/4" wall thickness x 13" length for a total weight of 9 lbs. I'd like it if I could get it down to 6lbs, but I don't think that'll be possible.
The machine shop told me they could machine down the wall thickness to be 3/16ths" for an approximate weight of 6.5 lbs, but it wouldn't be as strong... I don't know if it'll be strong enough, and neither do they.
I could chop an inch off the length I guess...

k, what's your advice. I don't want to make a mistake here, this thing isn't going to be cheap.

[gav]

I'd just take the inch off the length, or maybe 2 depending how big your foot and/or your board is.

[Frisbee]

Can you drop the diameter by an inch, I would make it 8" in daimeter and cut an inch off the length. I do not think you want to make it thinner as that will hurt the integrety

-Greg

[Steven Ragatz]

Check in with Thayr Harris. He hangs out here on P.net and I know he uses aluminum tubes for some major rola bola action.

I have not used metal, but have made do with large PVC tubes by putting ends on them to add support. I used half inch ply disks inset in the tube to help them keep a good shape. It is a balance whether or not the additional material to add structure makes up for the material you could take off, but it is worth consideration.

Keep in mind that if you are using tubes that are oriented vertically, the walls would not have to be as strong since there is little lateral pressure. The rollers shouldn't compress, but I would think the stacking tubes could be thinner. If you want to remove material, you could take out holes from the sides and make them 'circus' styled. It looks kinda disco in my opinion, but it would cut down on weight quite a bit.

Steven Ragatz

[Jim]

9" tube? That's huge. I've been using a 6" for over 10 years and it's just about perfect. Why are you using a 9"?

I just had this conversation with Dave Aiken. He was going to have the machinist bore out a ton of holes in his tube to make it look like swiss cheese, but the machinist told him it would be way cheaper to mill it down to a thinner wall. In the end, I don't think he did anything.

Try a smaller diameter tube and shave an inch or so off the end and see where that gets you.

If it's your "travel" tube, cutting a couple inches off the diameter shouldn't affect the show, visually, and it should save you a bunch of weight.

[Evan Young]

re: why 9" tube
The pvc pipe I stole from a constuction site 7 years ago is 9" and I think it kicks ass. Too bad it's 12 lbs.


I'm looking into an 8" diameter tube to save on weight. The machine shop said it should be a little less money as well.