Better Tommy Bars for a Sherline Lathe

I find the Tommy Bars that Sherline provides to be too short, too thin, and too bendable so I made some that are bigger, longer and stronger.

I started with a stainless steel capillary tube. The tube has an OD of 6mm and an ID of 4mm. It comes in pieces that are 9.84 inches long. I cut one in half which produced two tubes about 4.85 inches long (taking into account the thickness of the cut off saw disk), which is almost 1 ¾ inches longer than the Tommy Bars from Sherline. You can get tubes with thicker walls, which would be stronger and maybe easier to handle, but 6mm is the largest sized tube that will pass side by side when adjusting the Sherlne chucks. The 6mm Tommy Bars do not fit in the gap between a chuck and the headstock to get to the spindle so I use the spindle wrench that I made if I need to keep the spindle from rotating.

I then got some 4mm diameter hardened steel rods. They were 3 ¼ inches long. I would have rather have gotten longer ones but these were all I could find. I had some 4mm steel rod around so I used it as a filler.

I glued one of the hardened steel rods into a capillary tube with a bit more than 5/16” sticking out. I used CA glue that claims to be designed for metal-to-metal glueing. After that glue dried, I glued a short piece of a 4mm steek rod into the other end of the capillary tube to fill it. After the glue dried, I cut off the excess rod and rounded off the end on a grinder and a sander so that it had no sharp edges.

Note that the Sherline Tommy Bars are 5/32” in diameter, which is 3.969 mm. I found that it was easier to get metric tubes and rods so I used 4mm rods and 4mm ID tubes. The 4mm rods fit the Sherline spindle and chucks juts fine. 4mm is also the size of the Tommy Bars used with 3^rd party chucks.

Figure 1 shows a pair of the Tommy Bars.

Figure 1: Tommy Bars

I screwed a small magnet to the lathe’s plywood base and I use the magnet to keep the Tommy Bars handy, see figure 2.

Figure 2: Tommy Bar holder

Parts List

Stainless Steel Capillary Tubes

Hardened 4mm rods

Metal Glue

Magnet

2024-09-05