Zenta

Like I mentioned in my previous post I wanted to try out the reversed knee leg design. And since Archer won't have any upper body with arms like a humanoid it was pretty obvious that he should be a Mech robot. To be honest I don't think he will ever get any sort of weapon attached though.

Tying up all the servo wires is a bit time consuming (and boring) part, but nevertheless a very important job to do, not only for the aesthetics but most of all for functionality. When tying up the wires its crucial that they doesn't get in conflict with the bracket/servos and allow all joints to move freely. A picture of Archer in the middle of the wire-work:

Like many other Roboteers I prefer to use Wire Mesh Guard very often. Mostly because it looks much better but also for tying the wires together. Using wire mesh guard has some pros and cons though:

Pros:

• Protect the wires from being damaged.
• Very effective for tying up several wires.
• Make your bot look much better and more "professional " 
• The mesh guard are very useful for covering extended wires plug/connection (btw, I prefer to solder the extended wire).

Cons:

• Add slightly more weight to your bot.
• Depending on how flexible the servo joint need to be and where to place the wire,  the wire mesh guard make the wire less flexible. At some point you may need to skip the mesh guard or use  several mesh guards. Like I did on the ant inspired hexapod, A-Pod. These pictures show how all wires (from 25 servos, main battery, FSR mandible sensor and additional 6×2 wires for future use) are guided to the abdomen (tail) through a 2 DOF joint. (I can't say that was a very easy task, LOL):

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This picture show the rear part of Archer with all wires connected to the ARC-32 board. The most important part using the mesh guard was to keep the wires clear and free from getting in conflict with the Ankle Yaw (6.DOF) servos when the slider moves from one side to another:

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Placing the XBee and the switch regulator

For making all the electronics to take as little space as possible I had to use a XBee module with a chip antenna. This picture show how I placed it. I'm only using a custom made spacer for holding the module in place:

I'm using a Turnigy 8A switch regulator for converting the 2S LiPo voltage to a stable 6 volt for powering the servos. As you can see from this picture its a very tight fit between the servo plugs on each side of the ARC-32 board:

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Battery holder

When assembling Archer I did also make a battery holder, it simply consist of a 5mm ABS plate/sheet where I cut out some ventilating slots for eventual heat from the switch regulator. That being said, I've not experienced that the regulators get very hot though, its just a precaution. The battery holder does also holds the main switch and the regulator power switch. A picture of the battery mounted:

Note that I used some spring that originally comes with the 5645 package for holding the battery on place:

  

The spring are clamped between the ABS sheet (batt holder) and the spacer.

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And finally, some pictures of Archer assembled.

Standing while doing body yaw rotation:

A combination of body Yaw and Pitch rotation:

Note that this is still just a prototype for testing out the control algorithms. I'll make a small and light head for making it look a little better though. But at the end I'll probably make a completely new biped, maybe using some stronger servos. I've not decided if I should try a humanoid or a mech style robot.