Moday, 01-12-2003

14:00

I got PGR2 for the Xbox last friday and haven't put much time in on J5 til today.

I have managed to build a 4 pump piston compressor, powered by a 9v Technic mini motor...
The compressor works fine to move all 3 air pistons supporting J5's head at the same time and quickly builds up air pressure in twin tanks when the head pistons are not in use...
I've tried running the compressor on a 4.5v motor and battery box with a piston working against a spring to switch the motor on and off as needed, however the motor didn't have enough power to provide a good air output... the 9v motor works alot better, however the switching now becomes more difficult.
I have a choice of runing the motor off a 9v battery box with a homemade switch, or using a Midstorms RCX with a touch sensor...
...the compressor runs really well with 2 9v motors... the RCX sollution has been chosen!

Now I'm running 4 pump pistons, I've used up my supply of T-pieces... next task... make a 3 way distribution block, find a touch sensor and rig up the switching mechanism for the compressor.

I still have to rebuild the head... and figure out a control system for the head movement...

...shoulders... arms... tracks and motive power...

PGR2 time, my head is hurting.

20:30

20 mins PGR2... 4hrs Lego...
The compressor is now fully automatic, see the image for the components.

Click on a piccy to open in new window.

Ok... the compressor is HUGE... it also provides enough air for 13 piston movements once the tanks are fully charged... (charge up the tanks until the motors get switched off by the 'pressure sensor', power down RCX, and then switch one head piston until the air runs out - total 13 movements). Leaving the RCX on, the RCX turns the motors back on after 6 movements... meaning that the compressor cuts in when the air pressure drops by 46% of the maximum pressure. The maximum pressure is governed by 2 rubber bands... and can be adjusted by adding or removing rubberbands.

I still haven't been able to grab some decent shots of Johnny Five to work out the proportions of everything...
Currently my guesstimations will make J5 about 3' (90cm) tall, the compressor should fit nicely into the lower body...
The RCX and pressure switch can both be mounted wherever they're going to fit thanks to their remote conectivity... obviously, anything with batteries is heavy, so I'm going to try and use battery holders as counter weights for larger moving parts.

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This page is part a diary of the design and build of my Lego Mindstorms robot J5 (based on Johnny Five from the film short Circuit.
This page is also part of a frameset, Click here to view the page as it is meant to be seen