Dial Gauge Stop

At long last I was able to make a better dial gauge stop than the acrylic one. It had worked just fine for quite a while, but was rather clunky. The trick as indicated on the previous page was to keep it thin enough to not interfere with the ejection of the taper. I knew it had to be about .175 thick so I ended up with a piece of 3/16" (.188) aluminum.

The other criteria I wanted was to be small and not interfere with the compound rest handle when I was doing close in work and yet a little adjustable to insure good contact with the dial point. This is what I came up with.

Basically I wanted it to be about the same size as the end of the tail shaft casting and extend to the dial tip. Rough dimension are about 2.25" x 1.88". The trick for me on this piece were the 6-32 tapped holes on the edges of .188 AL, which meant I would only have about .025 material left on either side of the threads, and the bore for the tail stock shaft because I don't have any reamers and the shaft is 22mm (.866) diameter.

I laid out and cut the shape from a piece of .188 x 4" flat bar I picked up at my salvage place for a few bucks. It was cut with a jigsaw and squared up and finished the edges and corners on the disc sander. Then gave the faces a good clean up on the granite with some W/D.

Obviously, I was able to drill and tap the 6-32's but was extra careful making sure my drill press table was perpendicular to the vice and material. I usually use a ground 1/4 rod and my baby square, but this time I used my Wixey digital protractor which is good to .1° and a little longer 1/4" rod. Tapping was a little more tricky but was accomplished using my Tapping Guide with some aluminum angle in the vice jaws to to support it flush. All in all I didn't break through and the 1/2" long 6-32's are a snug thread fit.

To drill the shaft hole I was able to measure center from the tail shaft casting, and because the piece is the same size on 3 edges, it made it easy to transfer the numbers to the piece. The issue of the metric shaft size was solved when I realized there would only be about .0045" radial clearance if I took the hole to .875". Even with a .005 tolerance on the bit it would be fine because it didn't hold the planet together, just be secure.

I set it up in the drill press and drilled a couple sizes of pilot holes up to about 3/8". My dilemma was: whether to take it the rest of the way with Silver Deming bits or use a step drill? I chose the step drill because each shelf was about .188 deep and had a much shorter throw than the Silver Deming's. It would have less error than that far out and didn't have to change my setup. It worked great and the tolerance on the hole is very good...my hole came out to .880 on the button!

Once I put it on and all back together everything fit and landed where it was supposed to. Again I pretty much did all this on the fly with no drawings. I was also happy that I could eject a taper without pushing it off and didn't interfere with the compound handle...and it looked pretty clean.

The Last thing I wanted for this mod was a Thumb Nut for adjusting the pre-load on the Dial Gauge. It was a pain to use a wrench or nut driver every time I needed to move the dial gauge. This is what I came up with for my big thumbs. ;-)

The internal thread is 1/4-28 to match the slider bolt, and the rest is just eyeballed or maybe thumballed in this case. ~¿@ As you can see the Medium Knurl came out pretty good using my Spreadsheet, considering the brass is a piece of crusty old 1/2" rod I had in the bin. I did want to make the reduced section concave...but haven't built or bought a ball cutter...maybe soon though?

The dial gauge modification seems pretty complete to me now and will have a drawing for all the components posted here shortly, for those who want to give it a try. It's all made from things laying around the shop except the dial gauge and the scrap of .188 I bought...so less than $17. Like I said this has been one of the most useful modifications I have done on my Mini and just love how The Mini is becoming more useful and fun every day!!

I love that I can salvage old things and materials and make them pretty again or even something new from them, with and for my Mini!