Massive Design Project Involving Hexapod

[eucalyptus]

First off, this is an awesome forum. Glad to be part of it.

Now, the so-called massive design project will be the building of a hexapod with a bunch of extra little additions. I am an Electrical/Computer Engineering undergraduate senior student, and will be building this as a final project with three other team members. We hope to include an autonomous camera run by a stepper motor on top of the hexapod, and control both the camera and robot through a custom made RF controller. It will hopefully be a little seek and destroy hexapod with working computer vision.

But naturally, especially since we’re still somewhat green, there are many questions.

Thus far, we’ve gotten this chassis:

And have gotten three of these leg pairs:

So I guess we are currently emulating the CH3-R in body design.

I’ve also ordered a SSC-32 controller, and am about to order servomotors.

Now my first question, since I’ve seen conflicting information, is this generally run with 18 HS-475 servomotors, or 12 HS-645 and with 6 HS-475? As Xan’s awesome BlackWido? I definitely do not want to order weak servomotors and have to pay the price later…and I definitely would not want to overpay if it is not needed.

My second question involves controlling the motors. We want to build our own board, and are familiar with C, C++, and MATLAB. Any ideas on what to go for or how to bring this about? Would a simple PIC board work just as well as the BASIC Atom?

I will see if I can get my teammate to come here and post regarding the camera implementation and his FPGA work.

Glad to be a member of the website…we will post progress pictures/videos as they come.

[eucalyptus]

Had to remove the links…since I am not able to post links yet.

They are the conventional CH3-R setup, with the round chassis and curved legs. I will post the links when able to, and delete this post later.

[xan]

Hi Eucalyptus,

Welcome to the forum! It sounds like you’ve got some big plans.

@Eucalyptus

Now my first question, since I’ve seen conflicting information, is this generally run with 18 HS-475 servomotors, or 12 HS-645 and with 6 HS-475? As Xan’s awesome BlackWido? I definitely do not want to order weak servomotors and have to pay the price later…and I definitely would not want to overpay if it is not needed.

Thanks for the credit!

There a major design difference between the BlackWido (phoenix) legs and the CH3-R Legs. The CH3-R leg has got a double femur with the servo horn on one side and a ball bearing on the other side. This makes it very solid! The BlackWido (phoenix) legs got a single tibia and only rest on the servo. The HS-645 doesn’t only got more torque but also a metal gearbox. This is needed for the single femur design.

The default setup of the CH3-R is with 18 HS-475 so there isn’t any problem. But if you want it to carry more payload it’s better to switch to HS-645.
Now I think your next question will be: What is the payload with HS-475 and what is it with HS-645? I have to say that I don’t know But I know this, you never regret buying a more powerful servo. If your budget allows you to buy HS-645 do it! You could also go with the best of two worlds, 6x HS-475 and 12x HS-645 8)

@Eucalyptus

My second question involves controlling the motors. We want to build our own board, and are familiar with C, C++, and MATLAB. Any ideas on what to go for or how to bring this about? Would a simple PIC board work just as well as the BASIC Atom?

I think that a good PIC or atmel will do the job as well. The only turn side is that there isn’t much support for those processors on this side since most here use the BASIC Atom. But since your planning to build a “massiveâ€