Tuesday, 29 March 2011

Oily and Greasy

To balance my work on the nice and clean circuit design and software writing, I decided to get some muck work under way. To this end I have started reconditioning the donor parts. The first task is to strip it all down and clean up, then protect with a suitable finish. The donor parts came from the scrap yard in major chunks which required final disassembly.

Front upright assembly as supplied from the scrap yard
After a flurry of activity with hammers, sockets and a handy press, I reduced it to its component parts:

Some people choose to grit blast and powder coat, but many use the POR15 system so I thought I would give it a try. The process requires the loose rust removing, then a good clean with 'Marine Clean' followed by a coat of 'Metal Ready' to neutralise the rust and provide a zinc phoshpate coat. Finally, two coats of POR15 and you are finished. If the parts are to be exposed to direct sunlight, a UV barrier is recommended. Since these are suspension parts, I don't need to worry about that.

I set about cleaning the rust and grease off using wire wheels and paint srtipping wheels in my drill. Once reasonably clean, I could move onto applying the POR15 system. The paint covers well and the scond coat was applied when the first was 'dry with a slight finger drag' as required by the instructions. I trialled the system on the two front lower wishbones and two front uprights:

It seems to have gone reasonably well, so I need to press on with the remaining donor parts

Oil and Grease Free

Despite my lack of updates, I have not been idle on my Cobra project. I have mostly been working on the 'cleaner' aspects of the job, concentrating on some of the electronics I will be using. First off, I finished the Megasquirt auxiliary board and since it was a two layer (top and bottom copper) layout, I have had it made by one of the many PCB prototyping houses. This was recently delivered:

A quick check in the enclosure with the vehicle connector in place:

Now all I need to do is solder it up and give it a test!

In addition, I have been developing the vehicle electrical system and have decided on at least trying to build my own electrical modules. These will cover the instruments, direction indicators and heating controls. So far I have identified the use of a Picaxe Programmable Integrated Chip (PIC) as supplied by Revolution Education. These have a simple BASIC programming laguage and are used for a whole host of projects, mostly by hobbyists. This system will allow me to control the blower and heater solenoid valve, flash the indicators and drive instrument stepper motors, and display information such as miles covered and ambient temperature. A lot of work will be required to get these moduiles up and running, but I think they will be worth it in the end.