pic: 1885 Drive Train 2010

[JesseK]

loading photo ...

[dtengineering]

I'll be interested to see how the prototyping pans out, but wood is great for whipping up some models to test on the bump.

We have an 8 wd mock up that we tested in both wide and long orientations before deciding to give up on the wide orientation.

It looked good on the computer... but having something physical to manipulate made all the difference.

Jason

[Raul]

Are you planning on actively articulating the wheel pods or just letting them conform to the ramp?

[hipsterjr]

My, that frame looks familar

[Travis Hoffman]

Originally Posted by hipsterjr

My, that frame looks familar

Indeed....

[Valkyries_698]

we are doing something similar but with a slick wheel at the front,

We have been researching a system called Rocker-bogie

[fordchrist675]

I think you should ship the robot as is! I am sold on the wood chassis haha!

Looks like a ingenious idea.

[hyperdude]

Originally Posted by Valkyries_698

we are doing something similar but with a slick wheel at the front,

We have been researching a system called Rocker-bogie

Mars rovers, right? Funny thing, I came up with something almost exactly the same (prototype design).

Originally Posted by hyperdude

Mars rovers, right? Funny thing, I came up with something almost exactly the same (prototype design).

Tanks have been using a Rocker Bogie system since long before the rovers. Go take a look at the old Shermans, those are neat pieces of rolling coffins!

[Valkyries_698]

Originally Posted by CraigHickman

Tanks have been using a Rocker Bogie system since long before the rovers. Go take a look at the old Shermans, those are neat pieces of rolling coffins!

well this rocker-bogie was worked on by someone that is on the game design team

[Raul]

I believe the main advantage to articulating the wheel pods is to maintain a more level chassis while going over the bump.

Look at the wooden model in the picture Jason provided. If the rear wheel pods are articulated (rotated) so that only the rear-most wheels are touching, the angle of the main frame will be at a lesser incline and provide a greater safety factor to prevent the center of mass from getting close to the tipping point.

[JesseK]

Originally Posted by Raul

I believe the main advantage to articulating the wheel pods is to maintain a more level chassis while going over the bump.

Look at the wooden model in the picture Jason provided. If the rear wheel pods are articulated (rotated) so that only the rear-most wheels are touching, the angle of the main frame will be at a lesser incline and provide a greater safety factor to prevent the center of mass from getting close to the tipping point.

Interesting point, especially considering that the bumper zone rules aren't as strict while on the bump. Our primary goal with the conforming articulation (not sure what to specifically call it) was simply to maintain a controlled climb, peak, and descent. Doing so, we believe, will reduce the risk of tipping over. If anything, the heightened clearance requirements of this natural articulation may elevate the c.g., yet we are doing some very careful calculations (one of the mentors understands them ... I don't, heh...) to ensure we're under the tipping threshold.

For those interested, the actual drive train weighs in at 45lbs. Yet that's also with a subframe capable of withstanding some pretty high stresses due to high tension. We feel the extra weight is a good trade-off for stability & reliability.

[JesseK]

Originally Posted by Raul

Are you planning on actively articulating the wheel pods or just letting them conform to the ramp?

The current plan is to let them conform to the ramp. If there are a few pounds left over at the end of build season, we may add some sort of simple tension system to put a traction bias on the inner 4 wheels, yet all 8 wheels would still stay on the ground.

The chassis is based off of this concept that was thought of before the C-Base towers and Toughbox Nano's came out. That concept was based off of this concept of a natural terrain-hugging suspension.

[MrForbes]

It's a neat design. I wonder about the turning ability though...we are working feverishly to get our 8wd prototype running (hopefully today) so we can drive it around on carpet and on the bump. We are keeping the wheels fixed, but with spacing kind of like what you have--not evenly spaced, center wheels further apart longitudinally than the end wheels. With the end wheels raised just a bit.

We really like how 6wd robots drive, but were concerned about the bump, and we think the irregularly spaced, drop center wheel 8wd might be a good compromise between all the designs.

[scott]

HEY! I've seen this before...somewhere...