Hello everyone,
I am running ductile iron casting 80-55-06 (AS-Cast) on a CNC mill. The material is 0.270” thick, and we are boring out a 1.0012” diameter hole (not a full diameter hole), with a tollerence of +/- 0.0002”. We need an Ra finish of 24 or less.
We are using a Kennametal Romicron boring bar with a 40 radius carbide insert. We have this bore running at 2200rpms, and feeding at 1.5 inches per minute. Before the Romicron (finish bore) runs, we have a separate rough bore run, to leave 0.002” in diameter for the Romicron.
There are 2 of these bored holes per part, and on a new insert, we can hold our 24 or better Ra finish for the first two parts (not always). After the first two parts we have to start hitting the bore with 400 grit sand paper and a die grinder to get our Ra 24 or better finish, wich can sometimes be a pain.
My question is, there has to be a better way to maintain and get that surface finish out of the machine?? Hope someone can help, thanks in advance !
I am running ductile iron casting 80-55-06 (AS-Cast) on a CNC mill. The material is 0.270” thick, and we are boring out a 1.0012” diameter hole (not a full diameter hole), with a tollerence of +/- 0.0002”. We need an Ra finish of 24 or less.
We are using a Kennametal Romicron boring bar with a 40 radius carbide insert. We have this bore running at 2200rpms, and feeding at 1.5 inches per minute. Before the Romicron (finish bore) runs, we have a separate rough bore run, to leave 0.002” in diameter for the Romicron.
There are 2 of these bored holes per part, and on a new insert, we can hold our 24 or better Ra finish for the first two parts (not always). After the first two parts we have to start hitting the bore with 400 grit sand paper and a die grinder to get our Ra 24 or better finish, wich can sometimes be a pain.
My question is, there has to be a better way to maintain and get that surface finish out of the machine?? Hope someone can help, thanks in advance !