Construction begins !

OK... so today we start on the construction. The first thing to do is to make up the new circuit board to mount in to the handle of the device. We did this by measuring up the strip-board to the original control circuit. This was cut to shape the the appropriate hole drilled to make sure it could be mounted correctly. This was a tricky process as this meant that some of the copper strips were now not completely connected which would mean we would have to plan our circuit diagram pretty carefully.

The circuit board would hold the main components including the attachments to the USB control board, so I also made a small hole in the rear of the handle so that the lead that would attach to the base of the device would fit cleanly and the wires would not be fouled by the case.

We mapped the components out on the board and then fitted into place for a test.

Here you can see the new circuit board in its place, with the 4 wires that countrol the motors now showing, these would all be wired on the board including the battery terminals and control leads.

Next we added the 1st set of components, here we have soldered on the opto-isolator socket as well as the 1st 2 resistors. (the control leads would be added last as it makes the soldering job more tricky)

The 2 control leads were soldered into place (along with the common ground) and the rails tested for connectivity, before we connected it up to the USB board.

Here you can see the control leads all connected and a basic test was done to see if the opto-isolator was responding as designed.. (yep all tested good) we get a resistance drop across the output of the opto-isolator if we adjust the voltage on the USB board (we getting somewhere). We now have the controlling part of the circuit working fine.

The rest of the components were now soldered onto the board, including the two battery terminal wires (shown red and black) these would be looped through and soldered onto the exposed battery terminals.

The new completed control board was now offered up into place and a complete test was done.

Using the software we could now operate the main motor on channel one as well as the bunny ears on channel two, there now proceeded a small break of 40 mins while we drank beer, pissed ourselves laughing while we buzzzzzzed the device all over the dining room table. The pick up on the main motor was slightly behind the smaller one, but this would not be a problem as we can fix the motors start point in the software. The great thing is you now get complete linear scalability on each motor. No more ratchetted steps of speed, more like a smooth transitition from 0-100. (I sound like Jeremy Clarkson...now )

Here is the completed device with the top re-attached. The new circuit board is in place, with the transistors having to be bent over slightly to allow the board to fit into place. The whole thing screws together nicely, with the battery compartment underneath.

And here is the finished product....

A working USB controlled Rampant Rabbit (TM) the next step would be to make the USB control board smaller. Or what would be better would be to blu-tooth enable it. (designs are being drawn as we speak) The software will be easy to write, as I have complete development kit for the USB board so we can now get a simple client / server type application running. Although we did to a simple internet test using a remote desktop to control the device over the net. It WORKS !!!!

So in conclusion, YES you can make a homebrew Rampant Rabbit.

If anyone is interested .. the cost for the replacement board is under 5 pounds. (of course this does not include the price of the rabbit)

All we need now is some beta testers !!... and some market research.

:-)