Subject: Re: [atlas-craftsman IO] Making an ER40 Collet Chuck
Jody,
the set-true feature is like a 4-jaw chuck adjustment, but at the chuck/plate connection, instead of the chuck jaws.?
It is comprised of 4 set-screws located at 90 degrees from each other. They screw in from the outside of the chuck and they press on the registration boss on the adapter plate. Effectively, they allow you to indicate your chuck while attached to the spindle.
once your indicator is close to perfect, you tighten the mounting bolts and you are done.
You can make your first chuck without this feature. Just machine the adapter plate as per instructions (usually, skim the faces of the registration boss and backing surface, the same amount!), drill the mounting holes, install the ER40 chuck and you are done.?
You can always add the set-true feature later, if you want to have a simpler project to start with.?