Full Trike/Car Suspension Robot

I have been building this for the last 8 hours, this is only a test model to demonstrate that this is a method that can be used to create a decent suspension with all vex parts.

It uses rubber bands attached to wheels that are on a separate unit attached to the main unit by a screw a lock nut and some washers. The wheel can go up an obstacle and the main unit will not be affected, then when the unit is over the obstacle the rubber bands pull the wheels back into place.

It works great from the tests i have done but remember that this is only a crappy prototype model.

Later on i am going to upgrade the rubber bands to heavy springs so that the suspension looks really cool.

Here are some pictures

This is a good design to start building off of and if you add springs it will have a much stronger suspension than the rubber bands can provide.

Tell me what you think of this!

like its nice and flexible i’d drive it
i tried something simiilar to this but a little different though i didnt work cause i didnt have 4 servos just 3
i was wondering if you wanted to try it
it works like this
in the square bot theres 4 chassis bars and 2 angle bars
well you leave the inner chassis bars with no attachment to the angle bars
the inner chassis bars are connected to the outer with stand offs
the outer chassis bar instead o being connected to the angle bars with scews
you connect with a vex servo and shaft there will be 1 servo on each side of each outer chassis bar
what this does is makes a sideways suspension that may help getting over hard bumpy surfaces like dirty
you use the front controls for four wheel drive and back to adjust the servos

this is the other part that stopped me i dont have programmin kit to make the back buttons

controll ports 1,4,5, and 6
good luck if you want to try :wink:
i was gonna call it flex

I will try and get a video on youtube today; when i played the videos in slow motion it was easy to see the wheel adjust to the obstacle and then re adjust when it was over it.

The video should be cool if i can slow the videos down when finished but let me say that it is really cool.

And the flexbility of this thing is unmatched, it can flex a good 2 to 2.5 in on the main frame before the bars on the wheels stop it from hitting the ground.

If i add some heavy springs the suspension will be much stronger and if it were to fall really really hard the springs would absorb the impact and the robot would not be damaged.

Yea you should get the programming kit, buy the hardware kit and then get easy c pro because pro offers more features than easy c and this way you save $50.

Pro is no differnt, it just offers non vex sensor support like gyros ect…

Hows turning?

I forgot to post this but this is the test model and it has no turning.

I originally had each wheel in the back powered by two motors but i did not have enough chain to do that so i had to settle with 1 direction.

If i had more chain i could have built it but i need to get more.

yah, i was wondering about turning too, i though it impossible because the two front wheels are both on one axle

For people without a gear kit,
A similar hinged joint with gears instead of chains should work,
as long as the hinge joint to the wheel frame is the same as the gear axle.
The heavier the ‘unsprung’ weight, the worse the performance.
If you used direct drive motor to wheels, the motors (increased weight) would be in the unsprung section, but at least you wouldn’t need to send the torque across the hinge joint.

There is two possibility’s that i see for this design.

Either you use direct drive and attach the motor and gears on the wheel unit.

Or you could use the sprocket and chain kit.

I don’t see how you could do this with gears because each gear would move and sway which might cause them to slip and crack teeth off.

I put a video up on youtube so feel free to watch.

If you watch it please watch the entire video and get to the end so you can see the slow motion and the suspension working.


If you want an easy way to create suspension (coil spring suspension to be exact), I found at Lowes hardware store a box for a couple of dollars that is full of different sizes and tensions that are the perfect size for vex. Last night I made a full suspension tread that I am using as a base for a humanoid bot. I’ll post some pics when I get done (when I have some time).

Sounds cool, i will have to pick up a box of springs like that soon. Assorted springs would be nice to.