Tom Senior? 8" Rotary Table Rebuild

Rannsachair · Apr 17, 2022

I picked up this rusty very low profile 8" rotary table the other day.

Consensus appears to be it is likely a Tom Senior. Some original paint:

Was lucky to get every screw, bolt and set screw out intact some took the impact screw driver.

Stuck a few parts in the evaporust:

The sleeve next to the handle was seized to the shaft, so out with the torch:

The fixture plate was bolted and doweled on:

All apart, wire brushed and buffed up some of the smaller parts:

All looks not bad:

I put the calipers in the first pic in the evaporust then buffed them.

Seems to be no scale on the handwheel sleeve, not sure if corroded or there is a part missing:

Will need to do some research.

Rannsachair · Apr 17, 2022

The dowel and mounting holes for the fixture need plugged or I will get swarf into the worm gear, so getting to use my M300 making plugging dowels:

Quite a few to go:

Done enough today, seems to be in pretty good condition overall, will carry on making plugs tomorrow.

Seadog · Apr 17, 2022

I assume that the centre bush will come out? MT2 , perhaps?

Rannsachair · Apr 17, 2022

Seadog said:
I assume that the centre bush will come out? MT2 , perhaps?

Yes Graham, There is quite a thin walled bronze bush, thought I would damage it removing it, suspect has never been used.

RichardM · Apr 17, 2022

Should be a moveable degree scale from the others I have seen like this:

Tom Senior 8" Rotary Table for Milling Machine Low Height suit Bridgeport XYZ | eBay

Tom Senior 8" Rotary Table for Milling Machine Good size rotary table with minimal height, ideal for milling machines with limited Z travel. <p dir="ltr" style="margin-top:0...

www.ebay.co.uk

Rannsachair · Apr 17, 2022

RichardM said:
Should be a moveable degree scale from the others I have seen like this:

Tom Senior 8" Rotary Table for Milling Machine Low Height suit Bridgeport XYZ | eBay

Tom Senior 8" Rotary Table for Milling Machine Good size rotary table with minimal height, ideal for milling machines with limited Z travel. <p dir="ltr" style="margin-top:0...

www.ebay.co.uk

Will have a go at making one. Thanks

Rannsachair · Apr 17, 2022

Seadog said:
I assume that the centre bush will come out? MT2 , perhaps?

Been looking at pics, see what you mean the centre section should be removable so I can make a new one.

Rannsachair · Apr 18, 2022

Finally finished plugging all the through holes in the table:

As @Seadog spotted the centre bush was removable:

It is just a 1" OD so I turned a small chamfer and pressed it in the other way round:

I cleaned up all the threads and been researching what is missing.

The oil nipple holes appear to be 0BA:

For some reason there are 2 extra tapped holes beside the oil nipple hole, will just fit 0BA screws to plug. Discovered someone had filled the oil nipples with grease! So all the grease has been cleaned out.

The mounting holes for the zero label are 2 BA, so will look out screws and make a zero indicator:

I found some photos of one for sale on ebay, the zero indicator and dial:

and the graduated ring is split into 60 minutes, will be a challenge to make, as well I have another rotary table.

The oil nipple should have a brass label saying oil, so can make that too:

So still quite a lot to do, though clearer what needs done.

Agroshield · Apr 19, 2022

Rannsachair said:
...and the graduated ring is split into 60 minutes...

What is the worm ratio of the table (count the teeth on the wheel)? From the picture, it looks like the dial is divided into 4 x 60, which would be 90:1, the same as your Vertex (6 holes in a 16 plate for 240 divisions). You can save some stamping by not putting a '6' onto the dial.

Have a look on the Vertex as the zero indicator on that is a Vernier scale and allows you to resolve lower than one minute - if you have to make a zero indicator, you could incorporate that feature. I'd be tempted to go for 20 seconds, dividing the minute into three and then use the Mark 1 eyeball to split the lines if you need 1/2 a minute.

Rannsachair · Apr 25, 2022

Agroshield said:
What is the worm ratio of the table (count the teeth on the wheel)? From the picture, it looks like the dial is divided into 4 x 60, which would be 90:1, the same as your Vertex (6 holes in a 16 plate for 240 divisions). You can save some stamping by not putting a '6' onto the dial.

Have a look on the Vertex as the zero indicator on that is a Vernier scale and allows you to resolve lower than one minute - if you have to make a zero indicator, you could incorporate that feature. I'd be tempted to go for 20 seconds, dividing the minute into three and then use the Mark 1 eyeball to split the lines if you need 1/2 a minute.

Looks like its 120:1.

Rannsachair · Apr 25, 2022

Carried on cleaning things up and got the body painted

Some extra 0BA holes plugged and loctited:

Can see where the brass oil label was riveted on, will make a new label and drill out the remains of the old rivets.
What a mixture of threads on this BSF, BA and could not figure out what the ones holding the end plate to the shaft were so I could clean them up with a tap, turned out to be 3/8 UNF!

Rannsachair · Apr 30, 2022

Reassembled and lubricated:

No backlash and turns nicely, just the graduated collar and zero scale to make now.

galooph · May 1, 2022

Quite a transformation from your first photo!

Windy Miller · May 1, 2022

galooph said:
Quite a transformation from your first photo!

Indeed! Hard to believe it’s the same one!

Rannsachair · May 1, 2022

Windy Miller said:
Indeed! Hard to believe it’s the same one!

It definately is, just a few hours work. Not to the standards of some on this forum, though am happy with it to go with my Mill. There is something about taking a rusty piece of scrap and making it into something useful again that makes me happy.