Running stators side by side with different attempts at cooling would be a better idea as I really don't think this area has been explored in real tests. There has been a lot of speculation about various filers and holes in coils and lots of other things but no real useful test results.

Wire we know will run at 200C so that is the limit at the centre of the coil. It would be useful basing things on this to see what surface temperatures this equates to with various cooling methods. If the limits can be got to the point where vinyl ester resin could survive and retain reasonable strength with the centre turns of the coil at 200C then that is your limit.

If the vinyl ester will not hold up at the point where the centre turns reach 200C then you need to work at a lower temperature.

Unfortunately these will be life tests not instantaneous ones and will take a lot of effort. Short term you may be able to exceed these limits and I am totally convinced that many machines exceed these limits at least for short times. It may not result in failure but it will shorten lifetime.

I really have no idea where the limit lies, I found with polyester the stuff is stinking at 60C and I stopped testing at a surface temperature of 60 directly on the area over the wire of the coil. I based my rating on this and assume that with air cooling it will not reach this figure with my loading.

With this limit I have never tried the expensive vinyl ester but perhaps pushing the surface temperature to perhaps 100C may not be too bad but you would need to check the temperature of the centre turns of the coil, they will be the limiting factor.

Measuring temperature rise by resistance will only give average temperature and a rtd or similar would be needed to check centre turn temperature.

As I said previously I leave this field of research to those who are struggling with it. I have had no problems with burn out on any of my machines with my methods of loading so I see no reason to do this research for others.

To be honest I see nothing wrong with the simple approach and I also see no need to have burn outs, it is nothing more difficult than keeping the furling point safe. If you want more output then there are ways to increase it but always work within the stator limitations and there will be no problem.

If you build things from plans then follow the plans, everyone seems to want to change something or improve something and this is fine if you know what you are doing but such people don't need plans anyway.

Apart from one machine that Hugh mentioned I think his designs are conservatively rated and if you follow the instructions exactly you will be ok.

When Dan publishes his book I suspect the same will be true. There may be a slight problem following all the stuff on Otherpower as it is evolving all the time and it would be wise to use the latest data, whatever you do don't mix and match bits of early and later designs. Changes in one thing affect another.

I have no experience to confirm this but using a 10ft machine using the 2 x 1 x 1/2 magnets I would not let the output exceed 600W.If you find it exceeding this do something very quickly or wait for the inevitable. That may be 10 years away on one site or 2 days on another.

This burn out nonsense is not necessary, the axial design is excellent and is the best way to make good use of low winds. If you want enormous power once or twice a year then you need a different approach. If you are in a consistently high wind area and you can use lots of kW during the windy period without boiling your batteries then the simple design optimised for very low winds is not the thing you should be using. It suits most people with normal loads in normal wind conditions who normally have excess power on very windy days. Don't spoil it by failing to furl at a safe limit.