When I started working on my second version of the Spider, I was looking at the SES ( Servo Erector Set ) from Lynxmotion for building the legs. They also had the SCC-32 Controller for getting the legs to move by controlling up to 32 servos. At this point I had put together two legs, and was testing their movement with a servo controller.

I was looking through Lynxmotion's forums and getting some questions answered on the strength of servos when the owner of Lynxmotion posted about a new project they were working on, a 6 servo biped robot. I saw their parts list and as I was getting ready to order parts for my next set of spider legs anyway, I opted to get a pair of biped feet with my order. The end result is "Bart" shown below, although Lynxmotion has since named their kit BRAT.

The parts list is as follows. Parts listed are for the brushed aluminum finish not the black I used.

Part Number	Description	Quantity	Note
ASB-503B	Aluminum Channel (Length = 3)	1
ASB-04B	Alum. Multi-Purpose Servo Bracket (2pk) (BRU)	3
ASB-09B	Alum. "C" Servo Bracket w/ BB (2pk) (BRU)	3
ASB-06B	Alum. "L" Connector Bracket (2pk) (BRU)	1
ARF-01B	Alum. Robot Feet (Pair) (BRU)	1
S422	HS-422 (57 oz. in.) Standard Servo	6
HMSH-01	Hitec Spline Metal Servo Horn (Tapped)	6	Not needed
EC-02	SES Electronics Carrier	1
SSC-32	SSC-32 Servo Controller	1
WH-01	Wiring Harness - Battery Connector	1

Note also that since this was a kit that was still being worked on when I purchased it, all I had was the parts list and a picture plus a few videos of it moving. To figure out what I was doing, I took my first two spider legs apart and starting working on this side project. Here are a few pictures of the parts that were used.

C Bracket

Servo Bracket

Ball Bearings to help the joints, they came with the C Brackets I have.

By putting four servo brackets and C brackets together, I was able to connect the upper legs. Here they are before I screwed them together, the second image has the screws in place.

Then I used an L bracket to allow the ankles to rotate, which will be attached to the servo brackets which will make up the knees.

Here are the parts in place where the holes line up and everything is ready to be screwed together. At this point I am short two C brackets for the ankles and I am also missing the feet for the robot, so while they're on order I did a quick placement of the servo. I'm using Hitech HS-645MG servos for the hips and knees, which are stronger but more expensive than the ones listed on the parts list. They use the same plastic rivets that I have used to add windows to computers to attach to the brackets, making it easy to attach and detach the servos.