Tension version of Micro DRO in position measuring travel of cross slide
One criticism of the earlier version of my Micro DRO is the reduced length of travel resulting from the space required for the compression spring on the probe.
This effectively reduces travel by something like one third. The way round this is to use some form of tension spring or even elastic to ‘push’ rather than ‘pull’ the probe out.
A while back I bought a selection box of coil springs and this contained a number of unusually slim tension springs of just the right length. If anyone is stuck in obtaining a suitable spring email me and on receipt of a SAE I will send one on.
BTW those who may be curious about rare earth magnets according to Wikipedia Rare-earth magnets are strong permanent magnets made from alloys of rare earth elements. Developed in the 1970s and 80s, rare-earth magnets are the strongest type of permanent magnets made and have significant performance advantages over ferrite or alnico magnets.
There now, you learn something everyday !
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- Micro DRO stripped down, flat tension spring flattened further and ‘wings’ removed from probe.
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- Tension spring into position and held by small self tapping screws (ex discarded digital read out head).
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- Horseshoe shaped steel magnet carrier plate araldited into position.
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- Rare earth magnets fixed with araldite. Holding the little beggars in place isn’t easy !
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- Completed assembly of tension version of micro DRO
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- First compression spring version top with Mk ll tension spring version below.