Rotary Table Mounting Method

**LMMasterMariner** · Jul 17, 2017, 06:15 PM

The very first time when I tried to mount 6” HV RT vertically, I observed that this rotary table is not designed for my mill cross table. T-slot grooves on my mill (HF40939) table are not suitable for this rotary table. Didn’t want to secure rotary table by clamps as there is no enough space to do it properly, so it was required to drill and tap holes in mill table and secure RT with double end studs. Drilled 2 holes 119.5 mm apart and threaded them with M10 thread. Two socket set screws serve as plugs to prevent chips filling when rotary table is not in use. Looks like this RT is designed for some bigger mill as aligning keys are 16 mm wide and grooves at my mill table are 13.8 mm wide. Milling of these keys to 13.8 mm was done first.

Hope this info can help.

LMMasterMariner

**NortonDommi** · Jul 18, 2017, 03:43 PM

Hi LMMasterMariner,
I had the same problem on my mill/drill but used an alternative method which was to mount the R/T to a large angle plate and mill the mounting slots closer to center. This of course made the slots enter the relieved area under the head. Another problem was that the slots in the R/T are M14 and my mill table has M12 slots.
I used some scrap to make some T-shaped reducing sleeves to fill from M14 to M10 and also provide a flat bearing surface. The reason for M10 was twofold.
1: A lot easier to get bolts in place. 2: More room to maneuver a spanner.
Other mods were new T-nuts tapped for M10 and milling the locators from M16 to M14 to fit the slots.
One day I might get around to milling a flat where the sleeves sit but for now it works just mighty fine.

- Cheers.

**Toolmaker51** · Jul 18, 2017, 04:47 PM

An alternate would be mounting to a flat plate, to occupy less real estate than an angle plate, or accommodate longer parts. It is common to not index or mill parallel to the X-axis and a plate would allow that too.
We normally remove fixture keys for that reason, indicating the part for desired alignment. It also saves the surface from unintended marring; keys on larger tools are hardened.

**NickP** · Jul 18, 2017, 04:50 PM

LMMasterMariner, thanks for your post. Like most of the really good / helpful ideas it is really obvious when someone takes the time and trouble to show you how. Thanks for taking the time. Now where did I put my M10 tap?....
Cheers, Nick

**LMMasterMariner** · Jul 18, 2017, 05:39 PM

Hello NortonDommi,
Thanks for your ideas. Unfortunately I don't have large angle plate to mount 6" rt onto it. And yes, M10 bolts are strong enough to hold it.
Best regards
LMMM

**LMMasterMariner** · Jul 18, 2017, 05:52 PM

Toolmaker51,
Thanks for all your comments. Mounting rt to flat plate would be much better idea which didn't cross my mind at all. In that case it wouldn't be necessary to drill holes in mill plate. Also have 2 excuses for that; Didn't have any surplus flat plate laying around and already made fixed height tailstock for this rotary table.
Cheers
LMMM

**LMMasterMariner** · Jul 18, 2017, 05:55 PM

NickP,
Before drilling your mill table read my reply to Toolmaker51.
Cheers
LMMM

**DIYer** · Jul 19, 2017, 08:44 AM

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

Rotary Table Mounting Method by LMMasterMariner

tags: rotary table

**Hans Pearson** · Jul 19, 2017, 11:08 AM

Drilling and tapping your mill table - ouch. I too have a similar problem and have not yet got as far as solving it, but my idea so far has been to manufacture an adapter plate which will line up with the T-slots on my lathe/angle plate. However, thanks for your submission.

**LMMasterMariner** · Jul 19, 2017, 02:06 PM

Originally Posted by Hans Pearson

Drilling and tapping your mill table - ouch. I too have a similar problem and have not yet got as far as solving it, but my idea so far has been to manufacture an adapter plate which will line up with the T-slots on my lathe/angle plate. However, thanks for your submission.

Drilling and tapping of mill table (cast iron) was the simplest solution for me. I moved mill table all the way to the right and locked X axis movement. Two holes are in the same line that way and I don't see what's very wrong with these two holes. I don't see any job in near future which will require rotary table to be aligned in any other angle except 90 degrees.
Cheers
LMMM