Thanks for the ideas Micheal. I actually had an idea of making it from flat sheets in a box shape and either gluing the box together or using some type of screws. This cap, while having nice rounded corners is actually fairly rectangular in shape. Not round like on most engines.
I haven’t had the cap off in a while. In fact, I need to take it off to put a new set of points inside which I was able to find new. I’m hoping it will come off and go back on without breaking. It’s so old I’m thinking that it could probably break fairly easy. Especially being on a farm tractor that sat outside in the sun a lot. This magneto is exposed to the weather and sunlight. And I know that sun like can play havoc with various plastic-like materials.
I was even thinking of trying to incorporate an existing distributor cap in the mix and maybe trying to just build the rectangular base around a round distributor cap. But there’s another problem I almost forgot about.
I haven’t had this cap off lately, but if I recall, it’s not like a normal distributor cap that just has brass electrodes sticking down where a rotor flies by close and jumps the spark to the capt electrons. Instead I think it has some kind of spring-loaded rods (probably similar to motor brushes), that actually ride on the rotor and are activated only when the metal part of the rotor passes under them .
If that’s the case it may be extremely difficult to duplicate those aping-loaded electrodes. I’m going to be putting the new points I have in the tractor fairly soon. While I have the distributor cap off I’ll try to take some pictures of it.
Also, I don’t have a 3D printer, nor am I aware of whether a cap like this could be printed from suitable material. But if that was an option maybe I could draw up the cap in CAD and have someone print it out for me? As I say, I don’t even know if 3D printers could print a suitable material?
In fact, if they are that good I might considering buying a 3D printer myself.
As I say, currently the current cap is still functional. But I use this tractor almost daily, not all day long. But I’m always uses it for something. I’d hate to see this tractor die just because I can['t get a new distributor cap for it.
I can buy a whole new magneto, which is actually different from the one that is on the tractor, but will supposedly fit on this tractor. It has a different type of distributor cap. But even so they want $550 for the new magneto. I hate to spend that if I could just make a new distributor cap for the one I already have/
I pride myself on fixing and/or making a lot of things from scratch. But this distributor cap is a brand new challenge for me.
I don’t want to rattle on too much. But there is another idea I have which would probably work, but I would only want to go there as a last resort.
To begin with, this magneto died a long time ago. So I’m just using the points and distributor cap as a regular distributor with a coil and battery providing the spark. So this has already been a make-shift repair from many years ago.
As a last resort, I’m thinking that I could just take this magneto off altogether and just find an easy-to-obtain standard 4 cly distributor. And then hack that distributor onto the shaft that used to drive the magneto.
In other words, I have ways to fix the problem if I go to extreme lengths like this. A lot of work to be sure, but something I know I could ultimately do with the tools I have available.
But I’m thinking that making new cap for the existing magneto might be easier?
Obviously if I had a new cap to just slap on it that would be the easiest fix of all.