Converting a rotary to a flicker….
As time passes by, I’m pretty sure that the supply of early rotating armature magnetos will become more and more difficult to find. It was difficult enough 40 years ago when I first got my 1919 Lister P type! To overcome the problem, I modified a much more modern Lucas SR single cylinder rotary mag into a ‘flicker‘
The process is really quite simple and it will allow you to test run your earlier models without having to modify them. I chose the SR because they have a reasonably powerful magnet, not easily demagnetised and are fitted with well insulated and usually good working HT coils. Either rotation is acceptable.
I used some 1/2”by 1/8” flat bar to create an A frame above the spindle centreline. A hole drilled at either end to pick up the threaded holes in the magneto casing. At the apex I extended one end to form an L shape with a small hole drilled to hang the tension spring. Back then there was always a VONO sprung bed frame kicking about the scrap yards, they made ideal spring replacements. Initially the arm was made from 3/4” by 1/8” flat bar Brazed onto a chain sprocket that came with the magneto. However a 3/4” by 1/8” flat bar with a 3/8” hole drilled at one end and clamped between a couple of nuts on the magneto drive shaft would also work. At the tail end of this lever, and above centreline a second smaller hole is drilled to attach the other end of the tension spring. You can now secure the arm using a couple of nuts and washers.
Timing…..
To set the magneto correctly you rotate the arm to the horizontal position where upon raising the arm higher will fully close the points. Upon release the arm should spring back and reopen the points, a good spark should be seen each time the arm is flicked.
This magneto served me well over many rallies until I managed to obtain the correct style of Brass cased ML that I needed to complete the restoration. I apologise for the lack of photos and I hope my written description is detailed enough? However please don’t hesitate to ask questions if you’re in any doubt.
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Country: GB
