Newly Developed Chassis

[roboticWanderor]

Originally Posted by Rick TYler

Please tell the woodworker that it's pretty.

Will do!

Many thanks for your informative post, you may have just ended our own debate on the subject. we are really in the weeds on our chassis and drive train for next year, and will probably make several prototypes by the end of the summer.

the question is, what is really the most effective material for a FIRST Chassis?

strength? flexibility? yield strength? compression strength? rigidity? weight?

[AustinSchuh]

Originally Posted by Rick TYler

When we built the FRC robot "Wooden Thunder" four years ago, we created side bumpers out simple 2x4 Douglas fir boards planed down to 1.25" thick. We took some terrific bashes from other robots, including one that gouged out a chunk of wood an inch long and a half-inch deep, without any damage that would have actually hurt the robot.

Very interesting observation. Thanks for sharing. What you have described confirms what we learned this year.

After bending up a 1/8 " sheet of aluminum that was the front of our robot and then bending up a 2x4" piece of aluminum angle that we added in addition to the other 1/8th inch piece, we ended up putting a 1" by 4" by the width of our robot piece of wood up front also. That piece of wood seemed to take the shock of collision very nicely. If they ever make bumpers optional again, we are putting a 1" thick piece of lumber around our entire robot just to absorb the shock.

[travis]

Here is a comprehensive list of wood properties:

http://www.fpl.fs.fed.us/documnts/fp...tr113/ch04.pdf

The super exotics like bulletwood (or "beef oak" sometimes for its red color, the most desirable material for ship's masts in the days of yore), or kaneel heart are about twice as strong as teak, but normalized for density, they are about the same. Normalized for density, high performance woods are as strong as all but the exotic aluminums alloys.

We gave plywood a try, rather the Chinese stuff that masquerades as plywood, 2 years ago. General durability was more than sufficient; my one complaint was fastener holding. If I had listened to my gut and used the much harder Ipe (the most readily available of the high strength timbers in the US, pronounced ee-pay, called Brazilian cherry by the flooring industry), I think I would have had a much easier time. One of these days I am going to convince the team to make an Ipe plywood robot, and use one of the various bonded aircraft nut plates to make the threaded connections.

Travis

[Matt C]

Wood is an excellent material for a robot chassis, just ask Team 173 (Rage).

[Rick TYler]

Originally Posted by travis

If I had listened to my gut and used the much harder Ipe (the most readily available of the high strength timbers in the US, pronounced ee-pay, called Brazilian cherry by the flooring industry), I think I would have had a much easier time.

Try jarrah some time. I think it must be 50% titanium by weight. (<-- humor)

[SSMike]

Originally Posted by roboticWanderor

the question is, what is really the most effective material for a FIRST Chassis?

strength? flexibility? yield strength? compression strength? rigidity? weight?

This really depends on what the game is. If you are trying to design a chassis for a pushing game, like Rack and Roll or Aim High, you'll probably want a material that is strong, tough, rigid, yet still has some "give" to it (meaning it won't snap in 2 as soon as its hit). However, for a game like overdrive where speed was a much bigger factor than torque was, a chassis that is light yet still is strong enough to withstand high speed collisions is needed. We usually end up using some form of aluminum or a similar alloy for our chassis; a little heavier than wood, but it seems to work for us.

And of course, you can't forget weight constrictions, those little nuances that FIRST throws at us to make us use our brains even more. Always fun to deal with

[Gdeaver]

Good post Rick. The System3 is a good link. They offer a trial kit that offers a good sample pack of epoxy and laminating materials. Included in the kit is their epoxy hand book that is worth the price alone. Working with composites is not hard but takes practice. Week one is not the time to dive into composite construction with no practice. Now WOOD be a good time to get some materials and research for some summer practice. There are 2 types of fiberglass. E and S2. When ever posible I WOOD use S2 glass cloth. It can give up to 30 percent better performance for a little more money. Many FRC teams are stuck on AL because it's what they know. This summer is the time to experiment with other materials.

[roboticWanderor]

loading photo ...

[Lil' Lavery]

Wasn't there already a thread about this?

[Alex.Norton]

That's what I was wondering.

[Aren_Hill]

http://www.chiefdelphi.com/forums/sh...ght=wood+coast
yeppers

[roboticWanderor]

wow i did not know you guys could link a photo post into an existing thread! that's cool!

[Madison]

Originally Posted by roboticWanderor

wow i did not know you guys could link a photo post into an existing thread! that's cool!

We can't, so I wouldn't expect it to happen too much more.

Merging CD-Media threads with other threads breaks the connection back to the CD-Media information, as far as I am aware, and now it's impossible to track down this discussion from the CD-Media entry.

[roboticWanderor]

Originally Posted by M. Krass

We can't, so I wouldn't expect it to happen too much more.

Merging CD-Media threads with other threads breaks the connection back to the CD-Media information, as far as I am aware, and now it's impossible to track down this discussion from the CD-Media entry.

i figured that out the hard way...just now...
oh well.

[tim_reiher]

Well, we've made our chassis out of plywood for god knows how long (way before my rookie year, probably from 2002). It has been reliable for us, with the Europly we use tending to maintain strength and flexibility. But hardwood... hmmm... gonna have to check that for next year...

Originally Posted by Matt C

Wood is an excellent material for a robot chassis, just ask Team 173 (Rage).

Yeah, we got the whole wood chassis idea from RAGE; they were something of a parent team to us a few years back. We've built a RAGE chassis for a few years (We really are trying to phase out with some creative ideas, though. Not saying that those RAGE chassis don't work great, it's just about time we tried something new, I think.)