Another toroid construction method.


A couple of weeks ago I built a toroid for my new coil (that will be finished
in 97 or so, given as much time as I have).  I found a fairly cheap way of
building it and it looks fairly decent.  


two aluminum pie pans.  These are the type that are not foil, but are lighter
in weight than something that you would buy for baking.  

Aluminum drier hose. 

Aluminum solder.  I got this at a welding supply company for about $7.50 per 
pound.  It takes a little skill to use, but works pretty well.  Note:  This
stuff also sticks to copper, so you can make Cu-Al solder joints.

Solder the pie plates back to back so that they look like >-< in cross 
section.  Form the drier hose into the toroid shape and test fit to 
ensure that the ends touch when wrapped around the V formed at the edge of the
pie plate assembly.  When everything looks good, start soldering the 
hose to the pie plates until you meet at the starting point.  Then solder
the ends of the hose together.  In cross section, the finished toroid will
look somewhat like this O>-<O  

Notes:  The aluminum solder melts at a fairly high temperature, so you should
experiment on something expendable first.  I can use lead-tin solder just
fine, but this stuff is a challenge (but worth it).