Tube Turnings On The Lathe

This week I will discuss the process of turning square blocks of material into whistle tubes.

The first photo shows a square block of Cocobolo mounted on the lathe ready for rough turning into a round block. It is mounted on the left in a 3 jaw chuck and on the right with a "live" rotating center.

To get the block to the point of mounting it on the lathe, the block has had a 3/8' hole drilled into the center of the block end. A 3/8" wood dowel has been glued in place. This mounted dowel arrangement can seen in the second photo on the far left.

The second item on left of the second photo shows a block of Purple Heart wood that has been turned to a rough round shape on the lathe. The 3/8" dowel has been cut off flush with the end of the block.

The third tube in the photo is Red Dymondwood. It has had a 1/2" hole drilled thru the center of what had been a rough round block (similar to the Purple Heart block). A 1/2" gun drill was used to drill this hole on the lathe. For those not familiar with a gun drill, it is (as the implies) a long drill used in drilling gun barrels. It has high pressure air passing thru the center of the drill which blows the drilled chips back out thru the drilled hole. The drill assures a long, straight hole that becomes the bore of the whistle.

When the 1/2" drilled hole was completed, the tube was then mounted on the lathe using an expanding mandrel in one end of the hole and a live lathe center (the two items to the left of the Dymondwood tube in the photo). The expanding mandrel is a device that is inserted into the end of the tube and expanded by forcing the tapered end piece into the round outer piece of the mandrel. This assures that the tube is centered on the bore of the whistle. This process assures that the outer surface of the tube (when turned on the lathe) is concentric with the 1/2" tube bore used on my D and C whistles. To prevent the tube wood from splitting under the force of the expanding mandrel and the live center, the ends of the tube have been secured tightly with hose clamps.

The tubes in the second photo have been turned down to the final outer diameter of the completed whistle tube for C and D whistles . This outer diameter is approximately .640", yielding a very thin whistle wall thickness of .070" (70 thousands of an inch). The tubes in the second photo (from left to right) are Red Dymondwood, Purple Heart, Iron Wood (also referred to as IPE), Cocobolo and 2 Blackwoods.

Next week I will go into final process of adding the brass fittings to the tubes, the tuning of the tubes and the placement and drilling of the whistle tone holes.