The TS Engineering Quick Change Tool Post is a great addition to the Sherline Lathe but it's extra offset from the T-Slot and tendency to rotate under load are irritants. The addition of a tool plate and a simple mod to the QCTP eliminate both of these irritants.
The Tool Plate
Start work on the tool plate by sawing off two 3.5" pieces from a 3" by .25" bar of aluminum. Debur the plates, then square up and clamp these plates to the mill table, one on top of the other. Clamp on the cut ends making sure there is at least 3.1"+ free between the clamps.The bottom piece is a sacrificial plate to prevent cutting into the mill table. Now fly cut a 3.1" by 3" area of the the top plate to 0.2" thick.
Use a 0.25" end mill and mill the through t-slot. You will be taking a light cut into the sacrificial plate. Using the same 0.25" end mill, mill the 0.1" deep t-slot relief.
Using a #11 drill, drill the four mounting holes through the top plate only. Be careful and don't drill through the sacrificial plate and into the mill table. Using a 5/16" end mill, make the .075" deep relief cuts. These provide clearence for the T-nuts.
Trim off the sides to the final dimensions of 2.75" x 3.1" and you're done.
The QCTP tends to twist because it's bottom is flat. Under clamping pressure, the t-nut deforms the crossslide slightly and all the clamping pressure is exerted on a very small area around the center hole of the QCTP. The cure is to turn a slight circular relief in the bottom of the QCTP so that clamping pressure is exerted on the outside of the QCTP. It doesn't take much relief. I used a 2-stage relief of 0.004" toward the outside and 0.008 near the center. This is easily done with the lathe using the 4-jaw chuck. The picture shows the modified QCTP.
Copyright © 2004 by J. E. Rickenbacker. All rights reserved.