A new Dial Gauge holder - accuracy improvement

After some investigation it became clear the tap follower I was using wasn't particularly straight! The plunger has been bent at some point. i wasn't that happy with my Dial Gauge  holder so made a new one that actually holds the Gauge on centre height!


I started with a bit of rusty square stock. Bit of drawfiling and it looks vaguely presentable


Hole for the Gauge was centred and drilled 7.8mm(I used the DRO 1/2 function and an edge finder to get it central. 


Then it was reamed to 8mm, mainly to get a nice finish. I used suds to lubricate it as I'd run out of cutting oil.


I then drilled and tapped for the pinch bolt, no picture unfortunately, then it was time to slit the bar, using a new R8 slitting saw arbour that cam this week. It works quite well if you get the saw cutting clockwise, the opposite direction causes the bolt to unscrew and it all end up in a heap....


Clearance hole was drill half way though.


Then it was back to the vice to clean up the burrs with a triangular needle file. I used an M4 x 0.7mm bolt with a washer to pinch the holder onto the Dila Gauge.


This time I'm using a dead centre to pick up the centre pop.


I was able to get the runout to around 0.01mm which is plenty good enough for a steam engine.


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