Re: wood RSG

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

Greg; verry strong cast fiber glass can be made with 3 sheets of glass cloth
and wood powder from a cabinet shop sander. Dry the wood powder well over
night in your oven at the lowest heat so you dont burn the wood. Most cabnet
shops will give you sanding dust. Use standard fiber glass resin and add
enough dust to thicken the resin, but dont make a putty thick mix that wont
cast flat. This can be turned and tapped just like metal and is stronger
than you will expect. The cloth is only to prevent it being brittel. Dont
use saw dust, is is not fine enough to do a good job .
  Robert  H 

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Fri, 28 Dec 2001 18:32:42 -0700
> To: tesla-at-pupman-dot-com
> Subject: Re: wood RSG
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Fri, 28 Dec 2001 18:36:42 -0700
> 
> Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> 
> Hi Greg,
> 
> I think it will work.  You would want to go for 1800 (1500) RPM as opposed
> to the fast 3600 RPM gap speed.  You should also try to use the smallest
> diameter you safely can which will reduce vibration and centrifugal forces
> considerably.  You may have to play with little weights to balance it and
> such.  Of course, you definitely want a shield around it incase it gives way.
> 
> Unless the humidity is very high were you are, the wood rotor should not be
> a problem since the rotor conductors tend to operate near ground potential.
> One person even has a grounded metal rotor with zero insulation.
> 
> If you can true it on a lathe it should run perfectly.  Even if you cut it
> out (like I do :-)) at 1800 RPM you can get away with a lot.
> 
> "I think" it will work fine.
> 
> Cheers,
> 
> Terry
> 
> 
> At 10:40 AM 12/29/2001 +1000, you wrote:
>> I am having difficulty finding some cheap epoxy/fibreglass sheet to use
>> for a RSG. I was wondering if anyone has ever tried using well dried
>> and prepared plywood? While it isn't the best insulator, I would
>> imagine that a polyurethane coated disc of about 10-12" diameter would
>> probably insulate well enough. Another plus is that high grade plywood
>> can be very strong and is probably better at handling high temperatures
>> than most plastics. It is also cheap and easy to work with. You could
>> even impregnate the wood with polyurethane/acrylic/epoxy, etc using a
>> vacuum. What do you think?
>> 
>> Cheers,
>> 
>> Greg Peters
>> Department of Earth Sciences,
>> University of Queensland, Australia
>> Phone: 0402 841 677
>> http://www.geocities-dot-com/gregjpeters
>> 
>> 
>> 
> 
>