## 26744RE: Rotary Table Book or PDF

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• Sep 19, 2013

Hi, John,

I finally realized that it is what I originally thought; 25 seconds per vernier division.  It's just not terribly convenient.

No, I didn't get dividing plates for it, but I'm planning to make some in the future.

The table is a 72:1 ratio (the main crank goes 0-1-2-3-4-0), as does yours.  The difference is how the scale is graduated.  The main scale has only 12 divisions between degrees, making each graduation 5 minutes (300 seconds).  With a vernier with a total of 12 divisions, that makes each vernier division 300 seconds / 12 divisions = 25 seconds /division.

I'd appreciate any info you'd like to share on dividing plates, etc.

Thanks,

Charlie
New Jersey, US

--- In grizhfminimill@yahoogroups.com, <steelchipper@...> wrote:

On 9/18/2013 11:10 PM, clevinski@... wrote:

Thanks, Alan... that helps, especially the Sherline info.  I'm having a heck of a time figuring out how to read the vernier on mine; it's kind of strange, or I just don't know how to read it.  You can see the dial here

Degrees, Minutes, Seconds. The vernier is 10 seconds per increment.

Did you or can you get dividing plates with your rotary table? Since I do not work with astronomy or other applications where minutes and seconds apply, my main consideration is *divisions* like perhaps a 6 hole circle, a 50 division dial or for cutting some number of teeth into a gear blank disk.

What is the ratio of the internal worm gear on your R/T? Mine does 5 degrees per handcrank revolution (0 thru 4  to 0 again) . There are 360 degrees in a circle so 360 / 5 = 72. My worm gear ration is 72:1. Knowing this I can look at other more expensive rotary tables and find which dividing plates are available for them, as mine only came with one dividing plate.

For your degrees/minutes/seconds, I would say simply ignore the minus (left) 60 part of the vernier when cranking clockwise and focus only on the positive (right) +60 increments. 10 second increments means you are going to have to roughly guesstimate anything less than 5 seconds or so. Again, I normally go by divisions not degrees/minutes/seconds so the whole degree/minute dial is usually removed and replaced with a dividing plate.

I bought the LMS 2183 kit, back when U.S. dollars were much more valuable than they are now.
http://lmscnc.com/2183
which is the 1810 precision R/T with dividing plate and a tailstock. You may have some luck with reading the instructions for the R/T:
http://www.littlemachineshop.com/instructions/RotaryTable.pdf
and perhaps most especially, for the dividing plate that comes with it.
http://www.littlemachineshop.com/instructions/1811DividingPlates.pdf

Without dividing plate(s) a rotary table is severely limited in use whenever divisions are needed as opposed to degree/minute/second use (and even for degree/minute/second use it is hard to set for less than the nearest whole 10 or maybe 5 second increment).

Search online for how easy it is to convert from decimal degrees to degrees/minutes/seconds and vice versa. I could also post more about working out which dividing plate hole circle is needed for whatever division as may be needed, but as usual my post is already turning into a book so I'll stop it here for now. If it turns out your handcrank is 5 degrees per revolution, meaning your R/T is a 72:1 ratio, I can post back with all the bolt hole circles on the standard set of 3 dividing plates sold with the much more expensive units. You can see what hole circles are on the single plate that comes with my unit on the above LMS dividing plate link as well.

Cheers,
John Z.

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