the equation included such variables as:

length of wire, diameter of coil, # of turns, permeability of free space,
 as well as a materials constant of the wire (copper in most cases?)
intended to give some value (perhaps inductance?) which would then remain
constant throughout the coil, the only factor being changed was the diameter
and the # of turns, which derived the dimension and # of turns for the next appropriate
step-down from the previous radius, following the basic conical dimensions.
and, depending on the size, there was mention of possibly requiring a "gap" between steps
in order to maintain the perfect ratios, when stepping down to the next set of coils.
I took this to mean, that when calculating the diameter of the next step, it may not be
the diameter of the conical structure, immediately adjacent to the end of the previous step.
and for structural purposes, the next step of the coil began at the point on the cone that matched
the diameter of the coil turns. (some # of mm gap in most small cases)

If anyone has information regarding this equation, and can provide it here, it would be of great value.

I seem to remember Tesla's use of this being buried unfindably in the middle of a very long treatise on
coils and induction, resonance, capacitance, and general electronics physics, cryptically worded in Teslonian fashion.
the source of which, I am not sure.

simple trial-and-error with a multimeter should be able to narrow it down, using the resistance of the coils.

@smOkey


tnx for your input!


Trial and error.. that sounds like me : )

Some renders

Dear Cherryman.

Your last video took me way back in time!

I ran a successful foundry and precision engineering business for nigh on 30 years.

http://www.alynfoundry.co.uk/

I would suggest using Propane gas and a large torch for heating and try to find larger pieces of Aluminium scrap to melt. Using thin sections of scrap makes more " Dross " as the metal prefers to oxidise rather than melt.

Regarding your moulds you could use a metal die for such a simple shape ( if you have a Lathe ) of course. If your sand is too wet you will get steam forming that will ruin the surface finish.

Drop me a PM if you'd like to learn more.

Kind regards, Graham.

I do have a question, I added some salt as "flux"  i heard somewhere it helps the liquid being more fluent. is that a good idear ?

PS. Nice website and craftsmanship, you must be horrified to see an amateur plowing along, but i have to say it's fun.  Fire, molten metals.. creating stuff.

https://www.youtube.com/watch?v=sGi8Y95wsto


Here is a picture of the first and second.. It ain't much.. But I see improvement : )

Dear Cherryman.

Hmmm...  Salt not sure about that. A proprietary covering flux would be better but if this is just for a few castings the cost wouldn't be worth it. We used to use a " de gasser " tablet " rabbled " into the melt prior to pouring, this generated Chlorine gas which combined with the absorbed gasses reducing the risk of porosity. Might be the Salt actually de gasses ?

As to your endeavours, on the contrary. It's exactly the same as I over 40 years ago. I made so many mistakes to start with but with each subsequent cast the failures became fewer and fewer.

Cheers Graham.   

@Graham,


Woohaa! That's not fair! You make it look wayyyy to simple!! : )


I have to admit a torch looks mighty handy! , Although I do like the charcoal burning, this torch thing  seems a bit more easy and controllable.


Lol : I see the Video is of today..  Did I re-spark your casting blood?  I hope so!


Cheers Rob.

Did not have much time, but the Solid Utron's are almost finished!


(Not a render ; )

A few more minor tests.


Most of the time i forget filming. 


https://www.youtube.com/watch?v=mzE9a1XTW0g