Re: cast iron

(sorry if is this is a second post, Yahoo and I don't get along, it
sends stuff when I hit the tab key)

For a controller, you can get a PLC from
www.automationdirect.com for about $100. It'll allow you to program
any type of ramp up and down and hold cycles you can imagine.
A thermocouple will allow you to monitor the temperature and if you
want, a second will allow you to monitor the part in the oven.

or if you want, you can visit http://www.parallaxinc.com/ and get a
micro-controller and create you own device. Free software and a
GREAT list at basicstamps on yahoo
http://www.egroups.com/messagesearch/basicstamps?query

--- In CAD_CAM_EDM_DRO@y..., "Smoke" <gordonr@r...> wrote:
> Jay, do you know of a source for programable controllers and high
> temperature heating elements we could incorporate into home built
electric
> heating/melting furnaces?
>
> I'd love to build a somewhat larger heat treating furnance and I
know of
> others who'd like to do this as well. In fact, I just got a post at
> HomeFoundry about a guy that wants to build an elcectric furnace for
> controlling temperatures on salt baths.
>
> Smoke
>
>
>
> >I set up heat treat furnaces for foundries. The heat profile for
cast iron
> can differ greatly depending on the type of cast iron,
> >its thickness and geometry. The important factors are the ramp up,
soak and
> ramp down. Usually the temperature can ramp up rapidly
> >to 600F. The ramp up is then tightly controlled at not more than a
200
> degree F rise per hour until the soak temperature is reached
> >. For some castings this could be 1050F or as high as 1650F, This
> temperature is held for a soak cycle of two hours per inch of
> >casting thickness. The casting is then slowly cooled in the ramp
down cycle
> at a rate of not less than 200 degrees F per hour, to
> >600F. Often a fully loaded HT furnace will naturally ramp down if
it is
> shut down and bottled up at the end of the soak cycle.
> >
> >Aging castings is no where as effective as heat treating. Some
castings
> have an extremely tough skin that can take an edge right off
> >a cutting bit. Aging won't help, but heat treating can make it cut
like
> butter.
> >
> >Hope this helps.
> >
> >Jay Hayes
> >