4 Bores

[Adrian2]

Dear Folks;

I have a pump casting with 4 in-line bores to be made. Each is a different diameter, varying from 4" to 6" Dia. There are pilot bores in the casting for each bored hole. I want to dimension the machining drawing properly so that it is understood that each hole shares a common centerline and have each bore to be within tolerance.

I plan to true position each bore using GD&T sysmbols plus specify ANSI fits for each bore. Is there more I can specify on the machining drawing that would ensure I get good parts ?

Any help would be most appreciated

Regards Adrian

 

[meintsi]

I don't think that true position tolerancing will control what you are after.

1 true position callout for the first bore will centralize the outer bore to you face but you should probally use a cylindicity callout (concentricity+straightness) to keep the multiple sizes on center.

Without it you are asking for trouble.