From: Snag_one@msn.com   
      
   On 6/26/2024 5:21 PM, Jim Wilkins wrote:   
   > "Snag"  wrote in message news:v5hnnl$29e1b$1@dont-email.me...   
   >   
   >    I scored a Mitutoyo unit a while back at a yard sale . It only had   
   > one rod , 0-1" and I wanted more ... so I bought some on eBay . Thing is   
   > they must be for a different model micrometer , they're all 5/8" too   
   > long . And not 1-2 , 2-3 , etc . So I was thinking that I can cut them   
   > off to measure correctly in my unit . This will give me 0- 5" if I cut   
   > them to the appropriate lengths . It looks like I won't have to be   
   > absolutely on the mark since there is a calibration adjustment on each   
   > rod . I'm thinking that my Dremel in the toolpost clamp and a cutoff   
   > wheel , then a light polish with a fine grinding wheel also using the   
   > dremel . I have 123 blocks that I can set up to calibrate - maybe not as   
   > precise as a metrology lab , but I think close enough for what I do .   
   >    Does this sound doable , and any suggestions ?   
   > Snag   
   >   
   > -----------------------------------   
   >   
   > How about making a 5/8" long adapter sleeve for the head end, with   
   > appropriate threaded ends?   
   >   
   > If you set the lathe compound 6 degrees off square each 0.001" division   
   > on the dial will move the bit 0.0001" sideways.   
   >   
   > The mike will read the zero error and corrections will be to the one DIY   
   > sleeve, not all the rods. A screwup will cost you only the sleeve.   
   >   
   > The biggest problem may be matching the threads. You need to match only   
   > the mike end, you can make the cap.   
   >   
   > My depth mike is a Starrett so measuring its thread won't help you.   
   >   
   > When I set my South Bend up for metric threading I found that the   
   > standard 100/127 gear set wouldn't give me the fine lens threads I   
   > wanted, 120/127 gave more. I used a spreadsheet to calculate and   
   > tabulate the inch - metric equivalence of several possible choices.   
   > Change gears were much cheaper in the early 90's. They weren't a direct   
   > fit, I had to make a bearing adapter.   
   >   
      
      The way this is made there's nowhere to add a spacer sleeve . I've   
   got a whole 40 bucks in this set of used rods o it's not a big deal if I   
   screw one up . I think shortening the rods is really the only way to   
   make this work . In case you aren't familiar with Mitutoyo depth mikes ,   
   the thimble is 2 pieces . The top half unscrews and the rod is dropped   
   thru the hollow lower half . The top half is then screwed on to clamp   
   and retain the rod . The top of the rod is threaded , the collar that is   
   the clamping surface has 2 tiny setscrews plus a lock nut on top .   
   There's enough threads that if I screw up and have to take a little more   
   off I can , up to maybe .060" . About the only way I can see ruining one   
   is to bend it . That's a tight hole it fits in .   
   --   
   Snag   
     It's great to be straight !   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)