Small rotary table

[threesixesinarow]

This is a rotary table I made to use on my small Atlas horizontal mill. It’s a one-third size imitation of an old Bridgeport accessory but uses steel plate and a plain bearing instead of castings and roller bearings.

Like the Bridgeport it’s very low compared to its diameter, and like it, and I think old South Bends it pivots the worm to rotate the table freely. A pair of clamps lock the table in place and can be set to drag a little for milling things like grooves.

It’s about 6-1/4” square and 1-9/16” high. The table is 5-1/2” diameter with four 5/16” slots for standard 1/4” t-slot nuts. The worm drive is 90:1, with a zero-adjustable dial marked in 0.1 degree increments.

The body and hub are mild steel, but the table is from some harder scrap. The spindle is turned down from an old Morse taper adapter, and the main bearing and worm gear are bronze.



Side view, and comparison with the Marvin rotary table marketed for use with Atlas mills



With my 2” vise, and gashing the worm gear

[olderdan]

I like this very much, clever disengage and mesh adjustment. All in all a solid build, I hope its a winner for you.

[DIYer]

Thanks threesixesinarow! We've added your Rotary Table to our Machining category,
as well as to your builder page: threesixesinarow's Homemade Tools. Your receipt:

Rotary Table by threesixesinarow

tags: rotary table

[Toolmaker51]

A1 design and build. Infinitely better than a non-proprietary branded import.

[Tonyg]

Very nice build, like the height of the unit.

[ruxu]

A very nice compact and sturdy build threesixesinarow! The possibility to freely rotate the table is great additional feature.

I have myself been planning to either make a freely rotating table or buy a dividing table for my Sieg SX4 mill. After seeing this table I definitely know what I want. Any chance that you would share the detail drawings?

[threesixesinarow]

Thanks, guys. It works alright, and has been quite durable.

The Atlas mill makes choices simple since it has very small clearance and travels.

The 5-1/2” rotary table sold by them is 1-7/8” tall but isn’t geared. The 6-1/4” Marvin table is 2-5/8” tall and geared, but looks like it’s not enclosed. Both now seem to sell for prices more like collectibles than tools.

So I rummaged through my scrap and looked at pictures of different designs for something compact that resembled the pieces I had, I think 5/8” and 5/16” plate.

The Bridgeport seems to be very well thought out, and I’m sure I overlooked many details.

That sketch is pretty much all I drew, except for screw positions, though some things aren’t clear in it. The worm releasing shaft can be adjusted in the center of the knurled knob to set how it meshes when the knob is turned to engage it. The bearing hub is made from a discarded shaft coupler, and is bored with a taper so the bearing which is keyed to it and slotted like a collet can be adjusted by pushing it farther in with screws like on some old lathes.

The feed handle, and the design of the bent spring friction dial are from mini lathe parts.

[Gromet]

A well thought out and beautifully machined accessory . May we see more of your work?

[threesixesinarow]

Thanks, Gromet - you can see two things in the picture of preparing the worm gear blank for “free hobbing” - they’re adapters to use old Unimat parts for milling as well as indexing.

The text link “threesixesinarow’s tools” under my profile picture on the left in this post should bring you to a series of pages indexing some of the tools I’ve posted here, including those and ones similar to them.

[wizard69]

This looks really nice on my cell phone! Good enough in fact that I will need to look it up with my laptop when I get access.

Thanks for the fine workmanship and the pictures.