Receiver Counterbore Jig
A new tool for holding trumpet mouthpiece receivers while counterboring on the lathe. Simply tap the receivers onto the matching tapered mandrel and make sure it is centered. Then you can bore your counterbore with ease. Once finished simply thread in the 1/4-20 bolt, loosen the collet or chuck, and tap on the bolt to release the receiver from the mandrel.
The diameter of the shaft is .437” requires a matching collet to use. Can also be used in a chuck, but results will be dependent on the quality of your chuck.