View Full Version : Entry-level Mech Warfare

02-17-2009, 07:51 AM
I just discovered this idea of "Mech Warfare" in the latest issue of Robot Magazine, and I must say it's kind of like fulfilling a childhood fantasy!

Even though I live in Okinawa and won't likely be able to compete in any official events, I'm still interested in the idea. Unfortunately, I can't justify buying an $800 biped frame to the wife. Especially not if I still have to purchase the electronics.

So anyways, I was at the store today and they had a Wowwee Femisapien (http://www.wowwee.com/en/products/toys/robots/robotics/femisapien) on the shelf for $70, so I picked her up.

Has anyone tried using this inexpensive robot as the basis for a Mech Warfare robot? She has fast-moving arms, rotating torso, and a fairly decent walking speed. She can't stand herself back up after a fall, but that's the price you pay for saving $700!

Anyways, I wanted to throw the idea out there if it hadn't been discussed yet (a forum search didn't yield much discussion of Femisapien). I figure I can replace her onboard electronics with custom circuitry!

What are your thoughts?

02-17-2009, 07:58 AM
My mech is built on a Robosapien V1. Look in the member galleries under my name for pics. Also my blog has a bit of info that may be helpful.

02-17-2009, 08:10 AM
Very cool. I didn't search for discussion about her beau.

You're pretty pleased overall with the results of using the inexpensive frame? She's a little more svelte than her man, so I'm thinking I'll probably have to design some custom PCBs to keep the size/weight down.

I've done some electronics work before on little projects, but I've never worked on a robot. It's a bit intimidating, but exciting too!

02-17-2009, 08:18 AM
I just checked out your blog. Very nice.

My idea was pretty much the same, right down to the arduino and XBee... I was even thinking about using tank barrels, since those airsoft shooting RC tanks in abundance here in Japan :)

Very cool project indeed.

The only thing I hadn't planned for was the serial motor controller. I assumed she had servos inside (and the arduino can connect to them directly).

I'll need to strip her down before I can be certain, but if they are standard motors, I may try to get away with using L293 h-bridge instead of an expensive motor module. We'll see.


02-17-2009, 08:46 AM
My robosapien has simple gear motors, not servos. I would assume the Femisapien is the same. If you want to use an H-Bridge then you will also need some form of feedback like a pot in order to control your position.

The serial servo controller gives a bit better control over the servo positions than the Arduino and it allows me to "offload" that stuff to the servo controller so I don't have to worry about it or reinvent the wheel.