Rotary table

[projectnut]

Here's an example of a horizontal only rotary table/indexer. This one is not mine. Mine doesn't have the indexing option. :




I'm not sure if anyone today still makes this type of table. I've never seen one that can be used both horizontally and vertically. I can bolt mine to a 15" angle plate, but it's all but impossible to move around. The indexer weighs around 250 lbs. and the angle plate weighs another 150 lbs.

 

[benmychree]

That looks like a nice one, who made it?

 

[middle.road]

It is not as complicated as it sounds, no calcs to do, its all in the book ----

There's a 'book'?

 

[benmychree]

There's a 'book'?

Yes, there is a book! "A practical Treatise on Milling and Milling Machines" by Brown & Sharpe, I got mine when I apprenticed back in '64, it was one of our textbooks in class. It contains a lot of good information, including the setup for differential indexing that I posted above; some info is specific to B&S machines, but a lot of it is applicable to other manufacturers. Cincinnati also published a similar book, larger and more technical.

 

[projectnut]

The one in the picture and mine are both from the Index Machine Tool Company. The company was started in 1938 and sold to the Wells Machine Tool Company around 1971. According to their sales brochures Wells-Index is today the only vertical milling machine company to build and assemble all components in the USA.

I paid about $25.00 more than the one Mr Whoopee saw in the ad:

Brown & Sharpe positioner - $125 (Kelseyville, CA)

https://mendocino.craigslist.org/tls/d/kelseyville-brown-sharpe-positioner/7095634085.html

www.hobby-machinist.com

But I think mine has at least $25.00 more metal in it.

 

[Mitch Alsup]

I have a 10" horizontal only rotary table. I used to have my 4" vise mounted on its own rotation table, but I like the rotary table so much, I ditched the rotating base and mount the vise (semi-permanently) on the RT. This makes tramming way easier. A 10" table is probably one of the stronger links in the stiffness of my G0730 Mill. The 10" table is also just at the limit of what I can bend over and pick up.

As to horizontal capability, the 5" table you selected seems adequate, I, personally, would have been looking at a 6". But we are in the same ball park.

Indexing capability merely allows one to place a series of machining operations around a circle without looking at numbers. A RT without indexer can do everything a table with indexer can do, but you have to have more precision in your application of the dials--and never forget always approach the final dial setting from the same direction.

 

[Lo-Fi]

That is so complicated, I put that procedure right up there with rocket science.

Charts make it look like black magic, but the math is fairly simple. I have a dividing head with this capability and have cut some gears using differential dividing. It's quite fun! Rather than using charts, I coded myself a windows app to do all the calcs. The results are interesting, picking up some possible dividing solutions - both simple and differential - that don't appear in charts when there's more than one solution. I've also successfully tried a spreadsheet. Now I've got time on my hands, I'll finish tidying it all up to release it!

 

[talvare]

In an ideal world, I would have both but faced with the choice of an indexer or an RT, my choice would be the RT, simply because it is more versatile.

I made the same choice about 8 years ago but still wanted the ability to index with the hole plates as you would with a dividing head. I found a nice used 10" horizontal/vertical rotary table on eBay and then determined what plates I needed for it. It didn't take too long before I found a used set on eBay that would work well with my 120:1 rotary table. Then I made the other required hardware, eg; sector arms, crank, locating pin, etc. I don't use it often, but it works very well when I do.

Ted

 

[Shootymacshootface]

Joe Pi has an awesome vid about rotabs. I think he used a Phase ll. It has a vernier type scale on the handle, I believe that you can set it to 100ths of a degree. He is a master at using a rotab.
I believe that I have the same one that he used, a 10" Phase ll vertical only. I made a jumbo angle plate so that I can use it horizontally.

 

[middle.road]

Yes, there is a book! "A practical Treatise on Milling and Milling Machines" by Brown & Sharpe, I got mine when I apprenticed back in '64, it was one of our textbooks in class. It contains a lot of good information, including the setup for differential indexing that I posted above; some info is specific to B&S machines, but a lot of it is applicable to other manufacturers. Cincinnati also published a similar book, larger and more technical.

Man, how I wish there were still apprenticeships around when I got into the workforce in the late '70s.
The Gent that hired me as a draftsman in the toolroom told me that it was sad that 'apprenticeships' were no longer around but if I paid attention and listened I could learn quite a lot.
(40) years on, I wish that I'd paid better attention and listened. . . Little did I know.