Re: Simpleminded Rotary Questions

To: tesla-at-pupman-dot-com
Subject: Re: Simpleminded Rotary Questions
From: Open Minded <unknown-at-apc-dot-net>
Date: Thu, 09 Jan 1997 03:26:20 -0800
Subscriber: unknown-at-apc-dot-net Thu Jan 9 22:18:41 1997
Tesla List wrote:
> 
> Subscriber: cfbrush-at-interport-dot-net Wed Jan  8 22:52:49 1997
> Date: Wed, 8 Jan 1997 20:30:47 -0500 (EST)
> From: cfbrush-at-interport-dot-net
> To: tesla-at-poodle.pupman-dot-com
> Subject: Simpleminded Rotary Questions
> 
> Hi all,
> 
> Having recently upped my coil power, I would now like to build a rotary.  I
> am thinking of using a lexan disk with sections of threaded rod for the
> traveling electrodes (ends probably filed and rounded).  It would also most
> likely be a series quench style since I really like this concept.
> Stationary electrodes would be tungsten TIG points.  Here are some
> incredibly basic questions from someone who has never done any
> metalworking, or built much involving motors:
> 
> 1. Would phenolic or G-10 type material be better than Lexan, and if so,
> where do you get it and how would you go about cutting a perfect circle.
> Are there suppliers that do this?  I am pretty sure that the industrial
> plastics place I normally get my plexiglass from can make me a nice Lexan
> disk.
> 
> 2. How do you mount the disk on your motor?  I looked at my little cirular
> to see how it was done, but it has a threaded shaft on the motor.  Ok, so I
> guess I need some sort of clamp on arbor with a mounting diameter that
> matches whichever motor I choose (obviously).  Where do you get them, and
> what should I ask for in particular?  Any nomenclature that I'd need to
> describe this would be very helpful!
> 
> 3. I would like to mount the whole thing on a very heavy base for
> stability.  I was thinking of getting a big piece of aluminum from the
> scrap yard for this, and would use HV standoffs to keep everything clear.
> So here's a really basic question: how do you go about making threaded
> holes in something like this (tapping)?  What's the tool called??
> 
> Any help would be greatly appreciated!!!
> 
> Charles Brush
> 
> p.s. I haven't commented on any of the AVIs posted yet, because I haven't
> been able to view them.  For some reason my AVI->QT utility  crashes my Mac
> everytime I try it.  I will get this working eventually and am looking
> forward to seeing Bert's and everyone else's movies!


Charles -

  Lexan works OK. I kinda like the linen/canvas phenolics myself as
they are reinforced via the thread material. Key thing to the rotor
is that it is resonably balanced. You might want to contact a local
machine shop to see if they can't take the rotor to the lathe and
true it up for you. (Do that with the motor shaft arbor attached -
that way the rotor is true to the motor shaft unless the motor
bearings are really loose.)

  The 'thing' used to cut threads in a hole is, as you say, called
a 'tap'. The thing that cuts threads on a rod is called a 'die'.

  Take a look at my rotary gap pictures on the FUNET server under
the /turner subdirectory. Hopefully they will give you a few ideas.

- Brent

  (bturner-at-apc-dot-net - the other email return is to fool spamming.)