From: "CSC" 
To: "Atm" 
Reply-To: "CSC" 


The pitch should be warmed up and bedded against the mirror in a half hour,
I'd think.  Harder pitch usually means you can heap the weight on and speed
up the machine. If you are slow and less weight, then a soft pitch is o.k.

I use a mix of burgundy pitch, rosin and talc which is a pro's blend for
high speed.  The talc helps it act like a harder pitch so it deforms less
with speed and pressure.

Colin

-----Original Message-----
From: owner-atm{at}shore.net [mailto:owner-atm{at}shore.net]On Behalf Of John
Murray
Sent: Sunday, June 08, 2003 10:24 PM To: Amateur Telescope Makers
Subject: RE: ATM Gugolz 64 operating rage........?



G'day Bob,
        As I said in my post, the temp at night here is getting around 10c. To
me
this is quite cool but I don't know whether the pitch will think that! With
my machine I would imagine an hour or two or polishing would be enough to
warm the pitch up somewhat. From what I understand, machines require a
harder pitch than when hand polishing. Have you found this?

Cheers

John Murray
Whyalla
South Australia
Check our web page at http://astronomy.sa86net.com ATM and M-O-M stuff.

>
> Some of the "conventional wisdom" tends to indicate that the
number on the
> pitch is the basic operating temp in deg. F.  I'm not too sure about that
> but the lower number on the pitch does indicate that it is a softer pitch
> and since pitch is very sensitive to temp, I'd consider that pitch if the
> working temp in the room is going to be very cool.

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