$30 4WD Chassis

erco

Cheap and looks good at first glance, but dollars to donuts it uses the same cheesy undergeared motors as the Magician Chassis, as the ratio is quoted as 48:1. That's suicide for a skid steering car, which requires more drive torque than a 2WD differential drive chassis. I say NO DEAL.

If & when they gear these down to 100:1 or better, they will be controllable IMHO, but not at 48:1.

http://www.ebay.com/itm/4WD-Robot-Smart-Car-Chassis-Kits-car-with-Speed-Encoder-DC-3v-5V-6V-for-Arduino-/180914530167?pt=BI_Robotics&hash=item2a1f58a777

Edit: here's one where you can select 125 RPM or 27 RPM (better)!
http://www.ebay.com/itm/4WD-Arduino-Robot-Raider-Car-Kits-/280777542153?pt=BI_Robotics&hash=item415fa54a09

Martin_H

I was tempted to buy something like that, but I decided to build my own after seeing some videos of a similar platform. It was fine going straight, but had a hard time turning. I think the smooth tires coupled with the wheels being two far apart are the problem.

For my 4x4 I decided to borrow some ideas from Gordon's Rigel design and use Tamiya spiked tires http://www.pololu.com/catalog/product/1687 spaced close together like a bobcat. It seems to turn much easier.

erco

The original Tyco REBOUND R/C vehicle is 4WD and makes a great, nearly indestructable robot chassis. ~20 years old (!) and often found on Ebay or thrift shops for $5-10:
http://www.ebay.com/itm/Tyco-Rebound-4x4-rc-truck-only-truck-untested-/320974556198?pt=Radio_Control_Vehicles&hash=item4abb930c26

I used one of these a few years back to win ROBOT magazine's 4Bottle (figure 8) contest with a simple BS1 and some (big surprise) relays:

GordonMcComb

Put a shirt on, man! This is a family forum!!

-- Gordon

mindrobots

Erco, do you have a recording of a fire you can play on that big TV since it's blocking your fireplace?? :0)

Jim Fouch

erco wrote: »

http://www.ebay.com/itm/4WD-Robot-Smart-Car-Chassis-Kits-car-with-Speed-Encoder-DC-3v-5V-6V-for-Arduino-/180914530167?pt=BI_Robotics&hash=item2a1f58a777

I looked into these also, but bewear, they do NOT come with encoder sensors. They only come with the encoder disks.

erco

You boyz B funny. Shirt, TV, fireplace cracks. Thus far no one has mentioned the stopped clock on the wall, in close proximity to my face...

GordonMcComb

I was going to mention the clock. Dead giveaway that you took this video in time lapse, and the actual course was run in 14:32. The frenzied pendulum of the clock would have given away the trick photography, so you stuck some of your daughter's bubblegum on the back to stop it.

Come on, admit it!

-- Gordon

PS: While you're at it, your avatar inspired me. Check out http://www.budgetrobotics.com/item/Famous-Movie-Robot-Poster-Magnets----Add-Instant-Flair-to-Any-Room-T-shirt-or-Jacket-360. I found a public domain version of the poster.

erco

GordonMcComb wrote: »

While you're at it, your avatar inspired me.

So what's my cut, some wheel encoder disks or something?