Sherline Crosslide Digital Readout.

 

 

This describes making a crossslide digital readout for a Sherline lathe.  I wanted a digital readout that measured the actual position of the cross slide rather than the number of turns of the lead screw so as to not be impacted by backlash.

 

At some point in the past I stumbled across a picture that showed using a digital caliper as a digital readout for a crosslide on a lathe.  I recalled the image but not where I saw it so worked out the following based on what I recall of the image.

 

Mounting a digital caliper alongside the crosslide takes up a bunch of room.  Because of this it is obvious that the caliper would need to be attached to the right side of the croasslide or it would get in the way when working on small pieces.  This led me to find a left-handed digital caliper.  I could not find a 4" one, which would have been ideal, so I settled on a 6" one.  With a hacksaw I cut off most of the external measuring jaws, all of the inside measuring jaws, all of the depth measuring blade, and about 2" off the end of the body.

 

I then drilled 2 #33 holes in the stubs of each of the external measuring jaws.  #33 because it is the body drill for a 4-40 machine screw.

I also made two small blocks out of aluminum.  The first, which I will call the spacer block, is used to position the caliper off of the saddle enough to clear the caliper's plastic housing.  It is just a 1/8" thick block with two holes spaced the same as the holes on the stub of the stub of the external measuring jaw attached to the LCD housing.  The block was then shaped to fit the outline of the stub.

 

The second block was a length of ¼" square aluminum.  I drilled two #43 holes, spaced the same as the holes on the stub attached to the caliper's slider.  I then tapped the holes with a 4-40 tap.  I then drilled two #33 holes at right angles to the tapped holes so that the block could be bolted to the crosslide.  I will call this second block the "connector block" because it connects the caliper to the crossslide.

Modified Left-Handed Digital Caliper

 

I then bolted the connector block to the caliper with short 4-40 machine screws with lock washers. 

 

Connector Block Bolted to Caliper

 

I lined up the caliper onto the saddle & up against the side of the crossslide so that I could mark where holes needed to be drilled in to of the saddle and in the right side of the cross slide.  I then drilled 4 holes with the #43 drill to about 3/8" deep and tapped them with the 4-40 tap.

 

 

Tapped Mounting Holes

 

Then all I had to do was to bolt the parts together.

Final Product

 

(There is only one screw in the saddle because I broke a tap in the other hole - not recommended - but the connections is still very solid.)

The only thing funky about this setup is that the numbers count backward as you get closer to the centerline of the lathe.  If that is a bother, you can cover the minus sign with a piece of tape.