Re: Inexpensive crab module?
 

I'm pretty sure it's eight, but you'll need a second power source to use 12V, 18V, whatever, (or a converter) the controller runs on 7.2V

Re: Inexpensive crab module?
 

The VEX/Victor combo is out of the question anyways. Victors are waaaay too expensive. $100+ a piece?!?! I don't have to use Victors do I?

Re: Inexpensive crab module?
 

Well, that depends on your situation. You might be able to get away with an R/C car controller if you're not drawing too many volts or amps--look at a site like towerhobbies.com or robotmarketplace.com for some non-Victor speed controllers. (Scaling down your design might help here.)

You could also go with relays of varying sizes, which are cheaper--but you do that at the expense of maneuverability. (Would you drive your robot with Spikes, current issues notwithstanding?)

It can be done on a budget--it just takes time and a keen sense of bargain hunting.

Re: Inexpensive crab module?
 

Spikes have been thought of on different occasions. They go full forward/reverse and neutral right? So would spikes still work for crab drive? And relays... I don't know what they do.

Re: Inexpensive crab module?
 

Don't use relays. You'll regret it. You need smooth proportional control.

With that said, a cheap 12 volt pwm forward and reverse speed control with decent current handling ability is something everyone in this world needs but no one in this world can find.

The cheapest you'll get is $50 which will run maybe at 9.6 volts and I have no idea about Vex or other controller compatibility. http://www.hobbypeople.net/gallery/159205.asp

Re: Inexpensive crab module?
 

Some of the single channel Vantec speed controllers on RobotMarketplace might be a little cheaper than IFI, and the most of the dual channel speed controllers would probably come out to the same price or more. But, for low-mid (in realitive terms, compared to speed controllers for motors like the PERM) current applications, IFI makes an amazing product for a reasonable price. The Victor series and their spin-offs (eg. Thor and HV versions) are so good for their price (comparing to other speed controllers), that it wouldn't suprise me if IFI was selling them at a miniscule profit.