Machining the Packing Glands

The original plans, and the prototype, have two studs on the heads, and tightning a pair of nuts pressed on the packing glands which in turn presses on the packing material, sealing the rods. There are lock nuts that prevent the other nuts from vibrating loose.

After fiddling with tightning the packing on the other models in our locomotive roster, and after urging from Gorden, I decided to adopt a threaded packing gland nut, as Gorden did on his Shay engine.

The first step is to choose the size and thread pitch. This usually involves intense engineering. That means choosing what taps are on hand. Gorden had two taps the fit the bill. One 5/8 x 24 TPI, and the other 3/4 x 24 TPI. Since I was going to thread the Packing Glands Nuts on the lathe, the same threads per inch made a lot of sense. Not to mention the adjustment of the valve and cylinder packing nuts will be similar.

ValvePackingNut            CylinderPackingNut
Valve Packing Gland Nut             Cylinder Packing Gland Nut


CylinderCover

Even though I had a tap that what the correct size, I started the treading process on the lathe. This will help keep the treads concentric with the bore. I will finish the thread depth with the tap.

CylinderCover

This show the completed Cylinder Heads.

PackingGlands

Here is the almost completed Packing Gland Nut. I fininhed the part by facing the side just parted off, and then drilled the aqdjustment holes. See more pictures here.

ValveHeadPackingGland.jpg

Here is the Valve Head with the Valve Packing Gland Nut installed.

Karl Kobel

With the help of Matthew Kobel and Gordon Carlson (see his work on http://www.locogear.com/page15.html).