Being very bored with mold filling/rubbing down I spent most of yesterday’s available garage time thinking how to fit my coils into the CF enclosure within an aluminium box which will act as my Faraday cage. Concerns are:
a) Containing the coils within the physical space envelope;
b) Maintainability – being able to get at the coils and associated input/output leads;
c) Restricting water ingress to the enclosure and preventing puddling if it does get in;
d) Space to permit air circulation around the coils for cooling;
e) Minimising the extent of holes required in the aluminium container for input and output leads so as not to compromise the effectiveness of the Faraday cage;
f) Necessity for resilient mounting to avoid vibration damage? And
g) A design that I can reasonably bend and is strong enough to bear the weight of the coils (347 grams bare without fasteners/ spacers)
CAD techniques were employed – cardboard aided design, about 10 templates were cut as I tried out various increasingly more complex possible designs and eventually it became obvious even to me that if I could not make it work in cardboard I was never in a million years going to be able to cut and fold it in 3mm aluminium successfully.
The thing with doing stuff like this is that it is very easy to become fixated with one element (in my case yesterday where the spark plug leads were going to exit/run) and you ignore the other elements of the problem. The end design is a compromise whatever you do and any solution that favours one element to the detriment of the others is a bad solution.
I had a cup of tea and another ponder and by thinking laterally came up with a very simple solution which I shall make next week.
This morning these arrived and I am now waiting for the garage to warm up so I can a) try out my new gauges, b) machine the first draft hub to completion (taking out the bore to an interference fit 40mm to take the bronze bushes which themselves will be bored from both sides to the depth of the bearing ( 7mm ) and bored to 37 mm interference fit for the ball bearings themselves, and c) make a completely new hub with a larger OD so that the countersinking for hanger plate attachment screws does not breach the outer ring.
