where to source toroid cores?

[Magluvin]

no,  not cheeky.   lol

Especially in China, they want your business. Dont think of it as a handout. Its a real part of R&D.   Why order 10 or 1000 if they are not working for you. ;]  If it were an electric bike, ehh, samples not available. lol  But cores? 

Try to order samples from different companies. Even if they want you to pay for the sample, at least you wont end up with many that are not good for you. ;] Get several sizes. Find what works.

But at least we have these sources none the less.

Mags

[walsh350]

Yeah, I see your point. Essentially what we are doing is R&D.

Have already mailed a couple of companies with some initial enquiries.

Cheers

[quantumtangles]

I grabbed a couple of 4 inch circular composite ferrite toroid cores on ebay for about $12 dollars each.

I tried and failed to make torus shapes for my windings from papier mache (this took hours, ruined my bunker and they fell apart when I tried to peel them off the die/mould).

However there are cool videos about making your torus toroids on Youtube, and some interesting winding configurations.

They range from the mundane to the fabulously zany (mark rodin's coils being interesting mathematically in terms of the winding configuration which he calls vortex maths). www.markorodin.com

[triffid]

I have two ideas for cheap sources of iron.Wire clothes hangers which may be in your closet. second magnetic black sand from the river mixed with a resin that hardens.You have to use a mold to pour the mixture in before it hardens.I had a friend who used black sand and resin.Wire clothes hangers would give you something to work with quickly.I have no data on numbers.Just two ideas on sources of cheap iron for your project.Of course a magnet should stick to your wire hangers.I have seen the magnetic black sand resin mixture after it hardens.A magnet sticks to it just fine. triffid

[triffid]

If you have done any gold panning you should have seen black sand.Use a magnet to separate the sand that is magnetic from the nonmagnetic black sand.It is about half and half in my experience.triffid