Questions on sprue plates.....?

[Dutchman]

Greetings earthlings

Two questions..

1- I have to make a new sprue plate for a Ideal 2 cav mold as the sprue plate on it is severely off center. What thickness should the new sprue plate be? 1/4" or 3/16". I'm going to order a piece of low carbon flat ground stock from flatground.com .

2- I want to mill a trough between the sprue holes. What size ball end mill and how deep to mill?

danke doo

Dutch

[country gent]

What caliber is the mould? I make sprue plates from 1/4" starret o-1 gage stock. Cut to shape drill pivot hole and set stop shoulder. clamp blocks in mill vise and indicate 1st cavity to zero zero x and y axis. Zero machine. move over indicate #2 cavity and make note of dimension. Bolt sprue plate down tight and move back to Zero zero center drill sprue hole with #1 or 3 center drill, move to #2 dimension and center drill. remove sprue plate and with counter sinck cut to shape and depth with hole size what you want. A neat trick that sometimes works well is to clamp the sprue plate to a flat 1/2" bar and drill .060- .080 pilot hole thru plate and bar, then counter sink this backs the plate and helps allieviate burrs on the back side. As to the trough. a 3/8 ball end mill .060-.090 is good. Also consider a slightly shallower trough from last cavity to edge of plate ( .030-.045 deep same end mill) this allows over pour to be controlled If ladle casting a full ladle can be poured excess runs back into pot and a nice even consistant sprue is maintained.

[Dutchman]

The mold is 266469.

I'm using the big Lee electric pot.

thanks!

Dutch

[country gent]

That mould you might get buy with 3/16" thick. I like the sprue to be bigger than the bullets base or dia helps to keep the base hot and aids fill out some. Since I cast 40-45 cal rifle bullets cutting the new plate with an 82* countersink the 1/4" seems better. More work but, Another little tip when using the countersink run it slow and lots of oil. A squeeze bottle with a spout works good. You want a constant coating of oil. Slow rpms and heavy oil helps keep it from chattering. You might even do the finish cuts with a pin in the chuck and turning with one hand and applying pressure to quill with the other. A few full rotations by hand might give a very nice finish. Also a wood dowel turned to match the angle of the cutter used with fine lapping compound will really polish the surface up nicely.