Jim Struts moved...


First week of July

Jim Struts moved, not far just 20cm, all up. Bit of a problem controlling him as have not completed the on board computers wiring or software. We had the batteries on the ground and just attached the wires from the hydraulic solenoids straight on to them (not exactly under control). Low power motor is definitely a problem, to get enough pressure for Jim Struts to lift himself the centrifugal clutch slips. Nowhere near as quick or as powerful, as he should be!

Have nearly completed the wiring of the main system box and computer card (A relay and a couple of resistors are missing). When done will have to test and wire into the main chassis.

The hydraulic cylinders for the backward and forward motion are ready, just have to collect and fit (time is getting a bit tight for these kinds of things not to be done!). Collected and have started to fit them. This is not proving easy, as we have built as much as possible of the legs without the cylinders, and now to fit them we are having to remove more than we expected. Fortunately they have been manufactured correctly and fit for size as expected.

The gear box is going to need a rebuild because of the lack of power, will it be possible to see it move if it gets much slower!

First on board 'pic chip' programming for the receiver is complete. About to start the second, for the leg management, this should give some basic functions.

Think I will have to start a rewrite these progress pages with some real detail to make them understandable - very dull to read! (Have done a quick rewrite here and there).

Second Week of July

Have had a mixed weekend. Have built a new gear box, we now have sufficient power for Jim Struts to lift himself, but not to move forward.

Completed Jim Struts system box, cabled and installed. The system box has been named by the children as 'Eddie' the onboard computer.

EyeEye - Jim Struts - Eddie the on Board Computer

EyeEye - Jim Struts - Beeble Box the remote control

Eddie the onboard computer. It consists mainly of wire and three pic chips. The three circular items at the back of the picture are some of the hydraulic valves, the orange cap is the pressure relief valve.
Beeble Box the remote control.

The children have also named the remote panel as 'Beeble Box'.

The system box (Eddie) receives and decodes data from the remote panel (Beeble Box) okay. But, there is always a but, it has a few problems:-

Does not recognise the loss of RF well. More programming required.

Does not have sufficient drive (volts) for the MOSFET's. The Pic chip is producing about 4.1v need about 5.5v redesign of some of the circuit required.

EyeEye - Jim Struts - MOSFETS - Just for Steve
  This tag board has 8 MOSFET's mounted on it, they are capable of handling 45 Amps each, the hydraulic valves only require 1.2 amp, a minor bit of over kill. These eight control the hydraulic valves for only two of the legs.

Question can these challenges be solved by next weekend for the weigh in?

MOSFET problem solved, a few diodes here and there and all has come good.

Have tried a different system for detecting loss of RF, still not working!

Have reworked the RF loss detection and now seems to work. If RF signal is lost the Hydraulic solenoids get randomly activated by the noise coming out of the receiver for about 10 seconds then the detection of loss of RF parks all the valves, should prove interesting!

Have spent the morning wiring in the position sensors for the legs and preparing Jim Struts for the weigh in later today (Saturday 18th 1700).

The Weigh In



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