What’s a spacer?

[100LL]

I’m shopping dividing heads ...even though I have a few (long story)
And I’m seeing some “spacer indexers” and similar worded devices. Seems like they don’t have plates with holes but rather plates with notches cut out.

So what are they all about?

 

[Bob Korves]

Quick indexing, and only to simple and common divisions, like 2, 3, 4, 6, 8 ,12, 16, 24 -- If you are lucky. Good (and fast!) for production work on multiple parts. Not good for making most gears, sprockets, and stuff with oddball number divisions.

 

[Bob Korves]

The plates are called masking plates. The divisions are permanent, and the masking plates keep you from accidentally indexing into the wrong notch.

 

[magicniner]

Quick indexing, and only to simple and common divisions, like 2, 3, 4, 6, 8 ,12, 16, 24 -- If you are lucky. Good (and fast!) for production work on multiple parts. Not good for making most gears, sprockets, and stuff with oddball number divisions.

Bob,
There are "Spacers" which have, for want of a better description, "vernier holes" in the back plate



allowing indexing in 10ths of the primary divisions, the one in the picture allows anything with whole degrees as it can index in 1 degree increments,
Regards,
Nick

 

[100LL]

I have one of those Nick. I thought it was called an indexer. What I was seeing looks like a dividing head but funny plates with notches ( explained now as masking plates)

 

[Bob Korves]

Bob,
There are "Spacers" which have, for want of a better description, "vernier holes" in the back plate

View attachment 257323

allowing indexing in 10ths of the primary divisions, the one in the picture allows anything with whole degrees as it can index in 1 degree increments,
Regards,
Nick

Indeed, Nick. I have one of those, and it is useful. It fits in somewhere in between quick, simple, and Bozo resistant spacers and full out dividing heads. The spin function is also useful on the surface grinder.