pic: Articulated 6WD prototype

passive articulated suspension idea in lego form

How did this end up upside-down?

Edit: Thank you

That looks cool. Where did you guys find this idea, or did you design it yourselves? I was trying to figure out a way to do something similar.

I can’t tell for sure, but as the center wheel goes up, do the outside wheels go down? If so, wouldn’t that make the BUMPER ZONE move?

Well that brings up another question. How is the bumper zone height defined while on the bump?

we found that just raising the chassis with a regular 4 wheel drive works just fine. Also the bumper rules are a bit different this year, I don’t remember the exact height, but it is drastically larger than the 2inch restriction from previous years.

So although I personally love the 6 wheel drive configuration, it just seems more practical to save weight and work with 4 wheels.

But don’t let that stop you from trying it!

Driving over the bump looks easiest with a robot that has an open area in the middle of the drive train (as viewed from the side). That implies that 4wd or 8wd might be the way to go. 6wd seems to add a lot of complication to try to overcome the falling problem as the robot crests the bump.

And if your center wheels can lift up to follow the bump, the can probably also lift up in normal driving? so you really have a long wheelbase 4wd robot anyways.

My interpretation of this is that the BUMPER ZONE moves as the robot moves. It has to be this way, else an ELEVATED robot would move the BUMPERS out of the BUMPER ZONE. So if the robot is tipped or elevated as it goes over the bump, the BUMPER ZONE tips or elevates correspondingly. That means if the articulated wheelbase lowers the wheels, the BUMPER ZONE is measured from those lowered points. Before proceeding with an articulated design, it should be verified with Q&A.

Thanks, i had thought of this for an all terrain Modular UGV that my buddy and i are making. we were intending to use our oun design of tension/compression nitrogen shocks, but this is how it has to be done with the legos i have available. it still demonstrates the concept the same regardless.

I put in several questions to the Q&A last Thursday, including this one. This is one of two I have yet seen a reply posted against from the GDC.

<r07> The BUMPERS must be located entirely within the BUMPER ZONE when the ROBOT is standing normally on a flat floor,

If you read the last four words in this part of the rule the measurment is when the robot is on a flat floor. This most likely will be done durring inspection on a flat floor. All the robots bumpers will change there hieght durring transition through the bump, thier is no way around it. It also say’s you can not articulate the bumpers from the frame but it dose not say anything about articulating the drive wheels.

I like it! I wish our team had decided to do 6 wheel drive… instead we are using a swerve drive which looks promising but very time consuming to build and program.

It’s a great idea and is very creative. :slight_smile:


Joe how about a link to a video of your 6 wheeled articulated frame robot that you are currently driving around? I think others would enjoy it.

Video of our test robot with six wheel drive suspension going up a ramp.

Video of our test robot going up a 45 degree ramp.

Link to our web site with pictures of our development.


Team Update 3 supports this conclusion. Looks like you guys are all set!

We are using a similar idea, we are doing a modified version of the rocker-bogie system. It is similar to what the rovers on mars use. The max angle it can handle is 45degrees and the playing field happens to be a 45degree ramp.