Project: Tachikoma

http://forums.bit-tech.net/showthrea...=134493&page=2
he forgot us :<

I havent forgotten you!!!
I would post an update tonight.

Yay!!!

very impressive. the amount of effort is staggering. keep it up... and keep us informed... PLS!!!

Tachikoma is back again to work!!!


One year ago, I was making plaster molds. When I restarted to work on them, I found the plaster molds with a lot of cracks an pits, nearly useless. I was told that I should have sealed them with primer berore storage them. So they have a sand end, at least I use them for let my frustations out...

I decided to go for fiberglass molds. I thought to have better finish of the surface of the plugs to have better molds finishing and to have minimun sanding of fiberglass. (At the end I have to sand anyway, I am really tired of sanding. If you ever decide to build something on fiberglass, be ready to do lot of sanding)

I cover the plugs with layers of gel-coat. Is similar to polyester resin, with the same calayst. After it cured, I sanded all the plugs, what took ages.

Another recomendation: My first plan was to build the plugs as two parts, one for every part of the mold, and join it after. But after some trials it is likey I would have some bumps on the joint, so I joint the plugs halves together to have better finishing on the joint, like a replica of the final part.
After that, when I was more or less happy with the plugs, I cover with an epoxy primer.

To build the molds like this way, you need to divide the plugs in two halves. Fist cover the half not to be molded.

The half is marked by hand.

To build the flange, I used a flexible joint, like the ones used to seal the windows.

To finish the flange, I covered it with plastic tape.

Once you have the flange, comes the fun part with fiberglass.

First waxed the plug, by hand, 3 times.

Two layers of PVA, blushed.

Two layers of gel coat, brushed.

Two layesr of fiberglass mat, 300 gr m2.

ANd 24 h later can be pulled out of the mold.

Most of my plugs were destroyed with the process of pulling out the mold. Basically the foam, cardboard structure didnt have the strength to resit the stress of demolding. If some one have the idea of building something similar, I strongly recomend him to build the plug with some fiberglass to have the strength to resit the demolding process.

This is a part after pulling it off the mold

It has some extra fiberglass I cut with the dremel.

The two parts of a leg, prepraring to be joined.

I used fiberglass tape to join the two halves. After it cured, I cut the extra fiber and fixed imperfections with bondo.

The same with the arms.

The cannon

And the connector between the head and the backpack

For the head, I molded three eyes, and cut a hole in the head and inserted them.
I reinforce the inside with fiberglass and filled outside imperfections with bondo.

Some preasembly without the frame.

I have more to go for tomorrow

This project is AWESOME!!!

Good to see you working on this again buddy. Really nice work.
I actually saw one of those toys the other day lol and it reminded me of this thread haha.

very kewl. glad to see you working on it again.

+rep for the magnitude of the build

While I was finishing the plug for the backpack, I switched to work with the support frame.

Preassembly the central frame

This assembly system is used to build industrial ladders and stairs. The connectors are inserted inside the aluminium tubes. They had a setscrew that presses the tube and hold ti. It can stand more that 200 kg.

Mounting the central frame in the lower body. I did some holes to pass the tubes.

I also insert the elbows and the cannon the same way I did with the eyes.

Monting the knees

Cutting the tubes

Drilling the tubes for the motor supports

Holes in the legs to pass the tubes

Mounting the front wheels

And the rear wheels with the motors. The motors are 2212 NPC DC Motors, similar to the ones used for wheelchairs. Imported from the USA

Detail of the wheels mounting

Much more to come...

RC or voice command?

heh