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Hi Mario, That's great news! When you grind the flats on the induction motor armature, you create a preferred orientation between the armature and the fixed stator poles of the motor, allowing it to "lock" onto the incoming power line phase. Before modification, the armature would "slip" versus the incoming power phase - the slippage is why induction motors that operate off 60 Hz actually rotate at 1725 or 3450 RPM instead of 1800 and 3600 RPM. Grinding the flats forces the motor's armature to closely follow the applied rotating field. When the motor "locks", this means that the armature is now locked and in phase with the stator's rotating magnetic field instead of slipping as before. Assuming your system is in tune, fatter sparks are a function of power. It takes more power to make spark channels hotter and longer. As you increase your topload and secondary diameter, you'll begin to get longer and more powerful output sparks... as long as you also provide more power to adequately drive the larger system. Increasing the secondary and topload diameter will decrease the coil's operating frequency. Eventually, this means that the tank cap size must be increased, increasing bang size. Since input power is bang size times break rate, more current must be supplied by the HV transformer so that the tank cap can be recharged between bangs. A common mistake by beginning coilers is to leave the tank cap the same size and only increase the primary inductance to maintain tune after increasing secondary size. Under these conditions, the system may begin to be starved for power. In this case you get stringy and more spindly looking sparks. There's simply no substitute for raw power... :^) Best regards, -- Bert --
: Hi, I have finally got my six inch coil working pretty well now , many thanks
: to you. I am getting a steady three foot of streamers and I still have to
: tune it some more. I had to add another turn to the primary and probably
: still need one more. I built another rolled cap and after burning up two
: motors on the rotary gap I finally did it right and ground the four flats
: in the armature. My question is , what exactly is happening when you grind
: the flats to make it synchronus? Is it breaking up the field so that it
: isn't at the same frequency as the primary circuit or what is it actually
: making it synchronus to? Also is there anything that will make the arcs
: fatter as they seem to be thinner than they were on my four inch coil?
: Thanks Mario
:
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