Report my progress, I have finished aluminium parts, will receive package on Saturday.

Cool,

Look forward to seeing them! :)

Hi Matt, open below link to see my pictures, see if it's right direction please :)

http://rainway.51.net/Picture/webupload1.jpg

Looks good Tony!

How much did the parts cost in the end?

To avoid oxidisation, you can get the parts anodized.

Matt.

after hard negotation, i selected one supplier in source of China, near Hongkong. it cost me CNY 2600, around US$300. my supplier told me to do anodized but i need find another supplier, electroplate is the best choice I think... is there any problem if i do nothing? did u do it Matt?

i did a test today to use a plastic gear cut from a rocker, then punch it to my aluminium arm, unfortunately it was too tight to made gear distortion. (use a hammer). the smaller gear can be easily installed but i am afraid it is not strong enough to move legs.

I need order 20 servos, and i have damaged my first servo yesterday. I don't know how to control pulse before read the instruction :-( i plan to damage one more to get lesson learned... Matt - pls. advise if simulative servo is good enough to move hexapod? I can't believe a digital one is triple than simulative.

am so sad. I didn't aware that iC used futaba 3002/3003 in the very beginning, and I don't which servo is the best one, so i just search for the same picture on web, and i found one hi-top servo manufactured in taiwan looks very similar with ic, but i was totally wrong, it's dimension is 40*20*40 while futaba 3003 is 40*20*36. and i found this after everything is done!

I have no confidence with the hi-top servo, but i have to spend $200 to buy it :-) I can not go back so "good luck"

surprise again, i found a instruction and it shows the dimention is good for me!!!

http://www.tianyumodel.com/pic/yaokong/30031.jpg

Hi Tony,

iC uses 9206 and 3002 servos.

I'm not sure 3003 servos will give you enough torque!

Matt.

Hi Tony,

iC uses 9206 and 3002 servos.

I'm not sure 3003 servos will give you enough torque!

Matt.

--- mdenton 

Hi Matt, thanks for remind, I just order 18 3003 servos before read your message. 3.1KG @ 4.8V, I didn't find 9206 and 3002, the similar one is 9210/3003, but it's too expense, 9210 is 9KG and price is $75, 3003 is 3KG $10,what shall i do...

Hi Matt, this is my throught, pls. correct if i am wrong.

3 servos on each leg, one is coxa which link to body, another two for lifting calf and thigh. Lift calf and thigh is not a big job for iC as it won't real move the body, 3003 is working at 3.1KG torque so it's enough to do that job. the servo act as coxa takes the job to move the body, i guess you use 6x9206 as coxa :-) that's too expensive so i have 2 options:

1) Replace 6 coxa by 3010, it provide 6KG @ 6V and the price is about$35.

2) Use 3003 because when iC moves, it always has 3 legs lift up and another 3 move the body, so if my hexapod weight is around 5KG (with battery and mini-ITX), each coxa servo will take 1.65KG as average. it's just for horizonal move, not for lifting...

I did not test it yet as i am waiting for another 18 servos, god bless me. I need spend 1 week to assemble the hexapod as i need do some home work to make my plastic mounting bolt :), then the problem is how to programming and if my 4.8V, 2500mAH NiMH battery can or can not power 20 servos at same time.

Hi Tony,

I think you have this the wrong way round. The Coxa joint needs the least power, and the Femur and Tibia joint need the most power. Don't forget that when you add a long arm to your servo, the torque is decreased.

Eg. if your servo has 5Kg/cm of torque, and your femur is 100mm long, the torque at the end of the femur will be 5/10 = 0.5Kg.

You do not need much power in the first servo (Coxa joint) unless you intend on going up steep hills or towing a trailer! ;) The 3003 should be fine for the Coxa, but I would use servo of at least 5Kg/cm for the femur and tibia joint.

Matt.

Hello Matt,

For moving and lifting legs, the aluminium leg is very light so it's not problem, althrough the leg is longer than 12cm but 0.3KG is enough to lift a leg. But if it's for stand up, 3.5KG divided by 3 legs is 1.2KG, this would be a problem.

I punched plastic spline, i am waiting for final assembly, but i start to worry if hexapod is strong enough to stand up there...