Building The Big Bamboo

[maddox10]

Wood, mother natures own carbonfiber.

If it was good enough to build the fenomenal Mosquito it should be possible to build a competitive machine with it.

[mickburkesnr]

There is a de Havilland museum down south and they're rebuilding a Mosquito. It's in the hanger and you can look around it while the volunteers rebuild it. It's some machine I can tell you. There's also a WW2 glider there that you can sit in, and an example of a training plane that's built from wood and canvas. You can touch the skin and it bends. When you think that the material was used on a machine that could fly hundreds of feet in the air and deliver some damage, it's just quite incredible to think the primary material was wood.

[overkill]

Another way to hold the bamboo together is with a bolt down the length, like this cross section:



Its basically a huge barrel bolt . As long as the bamboo has metal sleeves on the ends, it shouldn't split under tension. one problem you are going to have is that the bamboo doesn't come in fixed diameters, so finding steel tube that fits over the ends tightly is going to be difficult.

[maddox10]

My example, the Mosquito, wasn't bolted, but glued. Wood is a very glue friendly material.

[mickburkesnr]

Glue would make changing parts quite difficult I think, plus if I rammed your robot would the glue on its own hold together?

[maddox10]

Just the same for welded metal monsters, isn't it? dented and ripped pannels have to smashed back together, grinded out, replaced and rewelded.

If a Mosquito could hold together with glue @ 600kph...

Several sports cars using aluminium and carbonfiber for chassis are glued as well. Not to mention the wings of several large modern airplains. And that's with materials that are less glue friendly than wood.

Just use the right glue and work it according the specs.

I have to admit, I didn't do that yet, as I'm a metalworker by training, and a welder by experience.

[overkill]

Mario's favourite plane got it's strength from curved plywood rather than a strong internal frame. It wouldn't be possible to get enough strength from gluing bamboo, there just wouldn't be enough surface area in the joints. If you wanted to slice all the bamboo up and make laminated panels, things might be different .

[maddox10]

Learn from the past. I myself lean to the battlecruiser approach.

BIG weapon, and just enough armor.

Not the One hit wonder approach as this wannabe historical example gives. Battlecruiser HMS Hood as real life example.

And Nick, if there is a favorite plane in my heart, it's the Vulcan, closely followed by the ugly duckling the XB70 Valkiri and the awe inspiring SR71

[mickburkesnr]

I could just imagine me with lengths of bamboo and the thing butchers use to slice ham, when my fiancée comes in and asks what the hell I'm doing. Although I'd have thought if you were using HMS Hood as an example you may have considered the Bismark? I mean what are the chances of a squadron of Sopwith Camels diving in to the arena and shooting the robot? :P

My philosophy follows from Boxing, which I used to do. "Hit and don't be hit". Really Boxing is the same as fencing. It's not about pure power, it's about landing a strike on your opponent then getting the hell out of there so they can't hit you back. So something that's agile, hard to hit, that's what I'd like to build. The benefit of this bamboo structure is that I should be able to pop parts out and replace them relatively quickly. I don't do welding, never have. But I have drilled holes in wood before.

That said, plywood is fairly strong. I might just make a steam engined bamboo robot with a plywood skin. Proper environmentally friendly!

[overkill]

I could just imagine me with lengths of bamboo and the thing butchers use to slice ham, when my fiancée comes in and asks what the hell I'm doing.

She's going to say "Got wood?"

[mickburkesnr]

She probably wood knowing her...

[daveimi]

Bamboo is basically a hardwood (wayhay) so you need to treat it as such. It will be hard to screw together and resist glue, but will be really good for drilling and bolting together.

[mickburkesnr]

Yeah that's what I thought daveimi, plus it should withstand some impact. Whether or not it'll be as strong as steel in this situation is anyones guess. But I'll find out!

[mickburkesnr]

The way it's meant to work is through an accelerometer, the same as what is in your iPhone to detect the position of the machine. If it's gone 180, then it'll flip after a small delay. You should be able to move it up to 90 degrees and it wouldn't trigger. So if the automatic self right isn't turned on until the machine is at a specific tilt angle.

[overkill]

Or you could bend some bamboo as shown below and automatically self-right with no power or coding:



If you grow your own bamboo, it is possible to train it into shapes like this with a frame - if you are aiming for an environmentally friendly bot, its the only way to go!