Unboxing (unbagging)? of IOIO OTG

This is my second IOIO OTG. The first one was DOA.

UPDATE: DO NOT ORDER THESE, they were all DOA. Recommended supplier of IOIO is sparkfunn and seeedstudio.

STAY AWAY FROM GEEETECH IOIO OTG

This time I ordered x2 to make sure I didn't get a bad one again (returns takes ridiculously long time sometimes).


It is designed by this guy, manufactured by geeetech and was delivered by dx.com.

It promises to give you access to hardware comfortably from your Java IDE, Normally an idea I don't like but in the name of efficiency I decided to go this route instead of working my way through all the low level C/C++/AVR stuff to get some motors and servos moving.

The idea is to use it for prototyping and when it gets serious I will port my efforts to more robust platforms.

IOIO OTG with bluetooth adpater in the bag

IOIO OTG with bluetooth adapter unbagged

Limb prototype v2.0 hip joint

I continued with my limb prototype and added a hip joint. It isn't the most clever design ever but it sort of works as intended. I have learned that joints are hard to get right because:

• The gears in the motors add slack that make the limb "wobble".
• The motor axle needs some kind of reinforcement to be used in a joint. In the prototype I just used the axle and nothing more, but I should look into ways of adding support on the back in addition to the axle, and probably add some bearings to add support.
• The geared motors are very long, and it is hard to conceal them in a normal limb body.

I flattened the other end of the femur and eyballed out places fo the screw holes.

I drilled the holes and found some more screws that would sit in plastic.

First two screws in place.

All 4 screws in place.

I decided where to attach the axle wheel to the motor bracket in the hip.

I marked where to drill holes.

Two holes drilled.

Wheel securely attached. I decided to just have 2 screws in this prototype.

Motor attached again.

Tadaa! Complete limb with knee and hip joint.

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Limb prototype v2.0

I got new parts from pololu.com and decided to go right ahead and create the second prototype limb for my robot. Thanks to the mounting brackets and wheels, making this prototype was a breeze!

Here are the steps:

I cut two 30 + 3 cm tubes like last time.

I flattened the end of the Femur with pliers.

I found some screws that would sit in plastic, and a drillbit that was "just too small".

I eyeballed the mounting bracket for where to drill.

Applying the pliers ensured that the tube stayed flat while tightening the screws.

Two screws in place.

All screws in place.

Backside.

Motor fastened to mounting bracket.

Eyeballing where to drill holes for wheel in Tibia.

The screws don't fit, but I just force them through the aluminum.

Screws in place.

Backside.

Wheel mounted on Tibia.

Knee joint complete!

Different angle.

Tadaa!

Limb prototype v1.0

OK, I finally have the stuff i need to create the first prototype of a limb for my robot. My expectations are:

1. Quick to build
2. Won't work 
3. Learn a lot

The process is documented thoroughly with images for every step below. But before we get to that, I would like to summarize what I learned:

• Making prototypes is really fun!
• The motor needs more torque to be useful for limbs of 30cm.
• I still need to find a way to determine the position of the limbs.
• The wood block broke (surprise)!

Now for the details:

I measured up two lengths of 30 + 3cm plastic tube, one for the tibia and one for Femur (thigh) and one for Tibia (shin).

I wanted the hinge to be at exactly 30cm so i left 3cm of extra length.

First i work on the Femur near the knee joint.

I flattened the end with some pliers.

On both sides of the 30cm mark.

I eyeballed what to cut.

I cut out the part that got in the way of the motor with my new dremel tool. 

Cutting complete.

I measured the motor screws to find the perfect drill bit.

First attempt at holes.

I had to widen one of the holes.

Motor securely fastened to Femur.

Now I need to fasten the Tibia to the shaft somehow.

A small block of wood to the rescue.

I divide it to get the right thickness.

Sawing parallel to the fibers is slow.

Sawing complete.

Now a hole for the shaft.

Shaft fit perfectly.

I found a screw to fasten the shaft.

The block was to long for the screw to reach all the way in to the shaft.

There, now it's perfect.

I drilled the hole for the screw perpendicular to the shaft hole.

Picaboo!

The block is now firmly attached to the motor shaft with the screw.

Holes for mounting the Tibia to the block.

Screws through the block.

screws on their way into the limb tube.

Tibia prepared for mounting on block.

Block securely fastened to Tibia.

Knee joint complete.

Tadaa!