Re: "vacuum" gaps

       You got me thinking about vacuum cleaner motors with this...

> A motor from a Tri-Star or Rainbow sweeper work well.  A standard
> canister vacu um cleaner motor will well also, it just pulls a
> little less air.  Shop-vac moto rs can be used, but they turn at
> twice the RPM's and scream quite loudly.  They pull about the same
> amount of air as a standard canister vacuum cleaner. I get mine
> from a local Rainbow dealer who takes "trade-ins".  I select a
> vacuum cleaner from the pile that still works and gut it when I
> get home.  The motors tend to be in poor shape, but if I get a
> couple of months from it, I've done well and it cost me nothing but
> a little time.  One nice thing about these canister vacuum cle aner
> motors is that most of them use a standard bolt circle and pilot
> diameter for mounting.

Sorry to change the subject slightly, but I get the impression these
things rev fairly high. What do you think their suitablility is for
driving a 10" spark gap rotor?
    BTW, thanks for organizing the capacitor deal. Mine arrived in 
perfect order and well padded.