# How to calculate volume of tires structure

I can show you once I have finished this job if you can wait a few hours.

sure, thanks

SketchUp can calculate the volume of all exploded geometry in a group.
The volume of the circle I drew is about 48.5 cubic ft. , the volume of all 15 circles is about 727.6 cubic ft.
48.5 x 15 = 727.5, so SketchUp calculated it perfectly.

Solids should have no internal geometry or basically anything doesn’t make sense in the real world.

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True. But unfortunately the presented pile of tire components doesn’t show any respect for “collision detection” for the components. Meaning that several components overlap. Exploding them and grouping all would not give you a SketchUp solid. There would be a lot of intersecting faces.

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As Wo3Dan commented, the OP’s model had to be edited a bit.

I think this is more like what he was going for. If they are actually “tires”, they are not “solid” as he had drawn.
But the actual volume of the tire (x40) would have to be subtracted.

Which brought up an interesting point to me. Any thoughts as to how one could construct his Tire Pyramid So that the concentric rings would all touch given the diameter of the tires?

Chris

Well, if the diameter of the tire was equal to one of say, 15 sides of a polygon you’d have a guide to do a copy rotate sort of thing.

Shep

Thanks, Shep,
I was missing the guides for the diameter!

Chris

Actually, I don’t think that method does work. It seems to leave overlaps, I was looking for the circles/tires to be tangent. Am I mistaken?

Chris

Would the arc tool, drawing semi circles get what you want?

LOL, in a pinch. But not the answer I was looking for. I’ve used that technique for furniture legs.

I don’t guess I’d ever tried to array circles with a set diameter prior to this post. Half circles, yes.

You’ve got to admit, it seems to be a challenge! Maybe I should pose this as a separate thread?

Oh, your first solution to the OP’s question should have been fine, for what he was asking. Kudos!

Chris

Do not forget to calculate the load factor as you may be missing material.

Looking down the road at the “real world”, this conversation seems aimed at creating a sand filled stack of arranged tires - more specifically at determining how much sand is needed.

In the real world, there will be losses between the amount delivered at the driveway and the amount added to the structure. Anticipating this, most installers will over order by 5-10%.

In this case, I would think that determining the volume of the outer shell - without subtracting the volume of the tires, would suffice to anticipate the losses.

Thus, while determining the exact amount of sand needed is an interesting problem, perhaps the ultimate purposes doesn’t need this amount of complexity.

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It’s fun to watch you guys try to solve it however!

The biggest problem with this thread was the omission of the objective in the first place. But then we’d have gone through all that “volume of a grain of sand” thing.

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Not to be too much of a wise guy, but if it were real tires and sand, shouldn’t the rings be modeled more with a U-Shaped profile to let the sand fill in the hollow part. That wasn’t pertinent to the initial problem of butting circles, but it might make a difference to the amount of sand.

I suppose, once you have contour rings for the sand pile, you could use Sandbox tools to make a more accurate shape…

Ok, sorry, I’m just making trouble instead of helping.

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Hi,
first of all, I very much appreciate all the effort that everyone who answered so far has put in order to solve this “problem”. I apologize if I didn’t specify well the main objective of the drawing, The idea is to create a somewhat pyramidal structure with tires for a schoolyard, which will be filled with sand. The tires (filled with sand) will only create the shape and give structure to the pyramid. The hole in the middle will be filled with sand as well, not with tires. So we will have have sand in the tires, just to make them heavy and difficult to move and inside the structure. I’d like to determine the volume of sand contained into this structure so I can budget for it. Since I have very little experience with using SU I imagined that there could be a simple way to find out the volume of the 3D form by just selecting the form and having SU doing some calculation for me. Still after all these contributions I am not sure which one to follow to get my goal accomplished.

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Frankly, estimating often comes down to “close enough”. I would think, you could use SU to get the general size of the thing for the number of tires involved (and they don’t have to touch perfectly, etc.) Then using that as a guide, just draw an approximate sized solid, cone shape engulfing it, more or less, and see what the volume of that is. The tires themselves might take up some volume, but probably a very small percentage.

An estimate will probably suffice given the cost of sand and transport. Sand “here” is about \$10/yard fob plus \$120/hr delivery. Washed sand will cost more. Normally dump trucks carry about 10 yards. You can order partial loads but the delivery would be the same. Placement of the sand will be laborious. Overall I think the volume of the tires (the rubber) can be omitted and excess sand, if any, stockpiled near the site.
I think I would adjust the size of the structure to fit most closely with the amount of sand you have delivered then add the tires to the existing pile and save some labor moving it.
A typical pyramid of 10 yards of sand would be ~14’ in diameter ~5.5’ high which calculates to 270ish cubic feet

I’ve become somewhat obsessed with this topic and the goal of it. I’ve had a go at the thing, to work out the total of sand required. It took (me) quite some figuring to make everything fit correctly. I used the technique shown by Jim Hamilton to create the tyre structure in this post:

The part that were a little tricky were the fact (to be tangent) each layer has unique tyres with different number of sides, so the sand that fills them for each layer (to be accurate) is unique as well. I basically filled the structure manually for each level. I probably could have merged the “inner” sand components into one, but I just left them separate kind of to show how it were done.

The tyre size I used were 225/50/17, not completely accurate modelling but a good idea of size.

If I’m honest, I would just stand there and say “that’s about x amount”, all this seems a little too labour intensive for my liking. Probably the hard way, but I gave it a shot.

TYRE PYRAMID IANT.skp (1.1 MB)

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You’re not the only one … the actual volume of the tire depends on the brand, size, and type. You used a 225/50/17 tire and I picked a 215/85/15. From the Goodyear website, I got this image:

and imported it to make a solid with the follow-me tool:

A slight variation to represent a 180/90/15 which used about 20% less material. I assume that the actual construction of this pyramid will involve various sizes and styles of tires.

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