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Originally Posted by Tom Line
I would be a little concerned about frame-torsion. Your design looks like you intend to screw into the wood, and over time the twisting of the frame may well loosen it up, especially since you're screwing into end-grain. I'd consider L-brackets with through-bolts to avoid that.
Also, unless there is a pressing reason for 8 wheels - I would avoid it. Unless you drop the middle 2 sets, you'll have trouble turning, and making 8 wheels the correct heights is really difficult. There's a reason stools have 3 legs rather than 4 (wood warps and twists over time). You can avoid that in part by using plywood, but that has problems all it's own if you plan on screwing into the end of it.
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Good points, I forgot to cad in the top corner brackets that would reinforce those joints. It could be constructed in a very similar way to our
2008 drivetrain which was able to go through three competitions with no problems. I am not sure whether wood screws would be enough or if through bolts would be needed, that's something that may need to be tested.
Oh, and the middle four wheels are all dropped 1/8" on this model.
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Originally Posted by M. Mellott
Question for anyone on the aluminum belly pan: what is the minimum sheet thickness one would use on such an application?
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Last year we used a .050 or .060 sheet, I believe... not sure on the actual thickness (squirrel might know?). It held up great and provided a solid mounting surface for all of the 'guts'. Adds about five pounds to the weight, but it compensates for additional bracing and a sturdy electronics board.
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Originally Posted by gorrilla
yes use L-brackets the dont add to too much weight for all there worth
and if the ends are fiberglass why not just glass it all its not very hard and that way you would have all the great performance of wood and the added strength of the fibergalss but it would still be able to give a little allowing for a smoother ride then a metal frame
the only problem with fiberglass is its kinda messy to work with and if it gets on a tool or something you might have to throw it away
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We're a little hesitant to take on a project like that... like I said this particular model was designed with manufacturing taken into consideration. That means that we cut a length of wood, drill some holes, and we have a side rail. The fiberglass ends come as a pultruded channel already, so we just hack off the correct length and bolt it on. (We have this problem of being lazy and trying to avoid too much labor
)
Some of you also mentioned using plywood, and I'm curious as to how it would best be implemented. One team member suggested laminating several sheets of plywood together to make the siderails...
One more thing I forgot to mention before (and why I like this design so much): Since it is constructed with siderails that require just a proper sized hole for a wheel module to fit, we could really stick wheels wherever we want. So, if it turned out that we didn't want an eight wheel drive robot after all, we could just drill another hole in the center of each side and we'd have a functioning six wheel drive robot. The difference between a 6wd and an 8wd bot with this frame is just two extra wheels and chains.