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View Full Version : Lathe Indicator



h6m3s4o7
09-13-2010, 06:49 AM
Colleges in Metal

I posted awhile back about attaching a ball to the end of a rod, that was to be part of a lathe indicator.

Here's a link to the nearly finished project:

http://s454.photobucket.com/albums/qq264/whoknockstheox/

Since these pictures were taken I'v added a adjustment screw to the sliding plate that holds the indicator body to the QCTP.

I was able to get 0.008 TIR using this rig. The end of the small rod goes in a center punch mark, but I didn't put much care into that end, just cleaned the worst of the cut off, so plenty of room for error there. I think the rod its self is slightly bent, came from an umbrella, so potential for considerable error there. I didn't finish the long end whatsoever, just as the wire cutters left it, I'm guessing that isn't as important for over all accuracy, but a sharp point would help. Lastly to check my results I stuck a long small brass rod in a drill chuck in the tailstock to act as a pump center, didn't put much effort into cleaning the work end on the brass rod, so possible error there also.

All in all 20 to 30 hours of work, by far the greatest portion involved fixtureing. An interesting skill building project for me. I didn't make any plans as what I make depends on what a I can find or scrounge. Be that as it may; the crucial movement elements are the two hard drive read / write head swing arm pivot bearings. The key design issue was trying to get the axis of the pivots to go through the axis of the rod on the same plane.


rOlin-a-long