Let's Make Robots!

"Wild Thumper" 6WD all terrain robot chassis


Vendor's Description: 


It's Here! Now with Video of it in Action on dirt using 34:1 gearboxes and new videos going down and up stairs and over snow with 75:1 gearboxes.

6WD_Silver_chassis_3__small_.jpg

Now available in silver!

Designed originally here on LMR specifically for robots, this 6WD chassis has wicked spiked 120mm dia. wheels and an anodized aluminium chassis made from 2mm thick plate. The chassis has 4mm dia. holes punched every 10mm to allow easy mounting of PCBs, servos etc. All nuts, bolts and screws are stainless steel. Brass fittings and suspension springs are nickel plated.

Two chassis segments between the wheels have been designed to hold 7.2V sub C battery packs (not included) as used in many RC cars. A total of 4x 7.2V battery packs can be fitted if necessary. These batteries are ideal for driving the 6V motors as well as inexpensive linear regulators to supply 5V.

6WDnew2.jpg

These photos show how even with one wheel resting on a large LMR mug (115mm high) all wheels are still touching the ground. It may not be a rock crawler but that's awesome for an off the shelf robot chassis.

6WDnew4.jpg

Ground clearance with the suspension lightly loaded is 60mm which is almost half of the total 130mm height when the topdeck is mounted on 25mm spacers.

6WDnew3.jpg

As you can see in this photo, with the top deck fitted you have a smooth deck to mount equipment on even when the chassis is flexed. Mounted on brass hex spacers, the top deck gives you room underneath to hide cables and PCBs to give your robot a cleaner more proffesional finish.

6WDnew6.jpg

The suspension for the front and rear is a single torsion spring. As the motor housings are connected to each other and not the chassis the front and rear can roll freely with the spring supporting weight and absorbing shock.

The steel cable is used to limit spring travel. The motor housings have 3 holes for each allowing spring tension and travel adjusment depending on the weight of the robot. Rubber grommets are fitted in the spring mounts to eliminate play while allowing the motor housing to roll.

The center suspension is similar but has 2 springs. Each spring connects from the motor housing to the chassis keeping the robot upright.

6WDnew5.jpg

The 6 powerful geared motors have steel gears and are fitted with powerful magnets to provide high torque. Top speed is about 6.6km/hr. These motors have a maximum stall current of 5.5A each so with 3 motors per side wired in parallel a dual "H" bridge rated for at least 17A per channel is required.

Rated voltage: 6V DC (min. 2V Max. 7.5V)
Stall current maximum 5.5A
No load current per motor is 350mA
Motor RPM is 10000 +/- 5%
Gearbox ratio is 34:1
Output shaft speed is 295rpm +/- 5%
Stall torque is 4Kg/cm

A 75:1 gearbox is now available!
This gives a top speed of about 3Km/hr and a massive stall torque of 8.8Kg/cm per wheel!!!

The chassis comes pre-assembled and weights 2.6Kg. Shipping cost to America or Europe will be approximately $48 USD.

Now available in 2 colour schemes:
Black with metallic red rims
Silver with chrome rims

Here is a preview of the 4WD version:

4_wheels-1.jpg

 

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

Wow , your 6Wheel drive Video is more than impressing - and i take my hat off for the super fast "on the spot" turning. This Beast will go anywhere.....its a winner.

Very fast and stable offroad - how is it for spinning on the spot/long high speed turns?
Looks very cool, amazing off-road cabability. I just have to get one of these.

Looks like it is a good climber with that Super-twist axle and high ground clearance.

The open top deck design is neat too - this was a feature i liked about Mr.Basic . (easy inter-change-ability)

Is there any give in the joints between the wheels, if not could portions of the body be slotted to allow some give for  some amount of left/right twist?

This Chassis is ridgid and steers via skid steering. To help it turn more efficiently the front and rear wheels are mounted slightly higher so that the chassis pivots more easily on the center wheels.

As the chassis is segmented it could be modified to bend but that would render the top deck useless.

The pololu trex is kind of pricey, but i think it should drive this nicely - it can control two bidirectional motors at 13A sustained or 30A burst, per motor. My bot reached 7 kph on a tradmill with this controller driving it, based on a pair of cordless drill motors at 12V. There was torque to spare, only the wheel size was holding it back. Its compatible with direct RC type input or serial, etc.

Another option is this controller by Dimension Engineering - however, it is a tad more expensive than the pololu offering. It is a bit more robust though: 25A per channel with 50A bursts.

http://www.robotshop.us/dimension-engineering-sabertooth-2x25-4.html

Although expensive it sounds great. 

I will be producing a much simpler controller in an attempt to keep the price as low as possible.

Thanks for the fast respond.

Damm that is nice, thinking of getting 1 for my school project. As it can be used outside.