We have discussed extending the length of the femor to 4". Is there a standard size for the assembly if I made the femur 4" pivot to pivot and used 32 tooth pulleys? 8) I’m not saying we should ditch the push rods, just trying to keep options open.
i like the idea of the MXL pulleys regarding it allowing for more of a degree of movement but would they work if the line of rotation was off. what i mean is can each MXL be slightly off:
http://i531.photobucket.com/albums/dd355/innerbreed/100_2160.jpg
not a massive problem. we could widen the servos but then it might mean the servo casing would conflict with the chassis.
maybe not. 
we could discuss ways around this if you wished to go with them.
It looks to me that the offset would be only 60 thousandths. I think that will still work just fine. 
I still have to solve the 32 tooth timing belt pulley to SES hole problem though. I’ve been wanting to do that for a while anyway.
Edit: on further study there is no way to put SES holes in the 32 tooth pulley. I will have to have a larger diameter one made. I will see about doing this and making a servo version with the same number of teeth. Making injection molded parts takes time, so lets just play with the push rods for now.
i was thinking this too. i was going to ask if the holes match up as we would need to put the ball baring on it for the tibia.
the push rods are working fine at the moment and its restrictions are minimal.
Can’t you put a “jog” in the pushrod?
Alan KM6VV
yes but its not the push rods that im on about. i was wondering if the pulley can handle the angle. the push rods work fine due to the ball socket.
Oh, the pulleys. yes, they need to be aligned (but you can “twist” a belt), otherwise, the belts tend to climb off the pulleys.
I mentioned making the femur, etc. leg parts made to “match” a specific belt/pulley combination, I don’t know if anyone picked up on that. Much easier then trying to find a belt to “match” your particular pulley/ center-center spacing!
Alan KM6VV
yes very good point the alan. i think we might just run with the rods for now. im not sure what plans jim has.
I’m building a visual aid for the pulley angle question.
I think I figured a good way to incorporate the pulley into SES builds. A 1" round, 1/8" thick plate with SES countersunk 2-56 tapped holes and the pulleys 4-40 tapped holes would allow attaching the pulley to any SES part. The plate would attach to the SES part, whatever it is, and the pulley would attach to it using two 4-40 1/2" screws. Due to the added 1/8" offset it’s not likely to work for this leg though. 
we cant work miracles.
great news about a way to incorporate the pulley into SES builds. i see more ideas coming this way.
have you ventured any new ideas on my Indirect Drive Leg Design and how it shall be built. any thoughts on that 4" femur?
Yes, my plan is to provide you with all the parts to build it including the 4" femurs. I’m still needing to draw it up, but should be able to get the parts made as soon as I get it designed. I think a week or two we will be ready to ship.
wow that fast. i look forward to seeing the parts. this is going to be a great project. im going to document the build (step by step if i can).
Visual aid assembly (for image) aborted. Will wait to do it right. Have designed the plate and will send it off for a sample. Working on 4" femur and another bracket that will remain a secret for now.
gotcha
Why not just use a “Z” bend to give it a more direct fit? Looks like with a proper “Z” bend, it will be perfect.
we could but the rods work fine as i mentioned.
Must be the angle of the shot. Looks like the ends don’t address the ball cranks (?) at a square angle. That’s what Mike and I are talking about.
Alan KM6VV
yes the camera as well as the femur angle doesnt help.
Here i have centered the servos at 90º.
http://i531.photobucket.com/albums/dd355/innerbreed/100_2188.jpg
The current femur is 80mm, We are extending the femur to 102mm. And that would reduce the angle that the rods are at anyway.
Awesome project! I really like this new leg design, as it will make a robot really look more like and insect (or spider in an 8 leg configuration.
8-Dale
Ummm, 8 legs! Jim… LOL 