How does this rotary table bolt down?

[Philip AParticipant @philipa30666]

Can anyone make out how this rotary table attaches to the lathe table? I can see t wo small holes, maybe it needs to be dismantled and then use those holes to bolt down?

[Philip AParticipant @philipa30666]

[Clive Brown 1Participant @clivebrown1]

If those 2 small holes are threaded then they might be for attaching tenons to align the table with the milling machine tee slots, if that should be required.

Can't say on the bolting down method though, unless its clamped from the side

[Colin HeseltineParticipant @colinheseltine48622]

The two holes are almost certainly tapped and will be for fitting tenons for alignment in the slots on the table. There is obviously a single slot at the top for a holding down bolt. I would hazard a guess that if you turn it round you will see a slot/ledge will can have a clamp located in it to hold down that end. Difficult totell inthe picture but are there holes in the face which it is standi g on so you an bolt through to hold it vertically.

Colin

[SillyOldDufferModerator @sillyoldduffer]

Not clear from that photo is it!

With the chuck upright, the bottom slot is notched to take a T-Nut:

And on the other side, the 'ear' takes another:

The two big holes unused in the first photo are for T-Nuts & bolts when the table is mounted chuck-sideways.

Note the mounting slots and holes in the rotary table have to align with and be sized to suit the T-slots in the machine table. Pictures are of a 6" Vertex clone on a WM18 milling machine.

Dave

 

 

 

Edited By SillyOldDuffer on 06/12/2020 13:16:00

[HopperParticipant @hopper]

In the vertical position as pictured, there are two bolt slots in the base on the other side for T bolts to pass through.

In the horizontal there is the one slot shown at the top in the picture and the other end would have to be clamped down unless it has the slot like SOD's above.

Edited By Hopper on 06/12/2020 13:19:01

[Pete RimmerParticipant @peterimmer30576]

I'd knock up a small toe clamp to fix that down. Saves messing about trying to find just the right length bolt and fiddling with a thin nut in the slot.

[Phil H1Participant @philh196021]

I think my rotary table might have less useful features. I can just about get the ends of some slotted clamps round mine but they never fill me with confidence because the top flanges on the casting are so small and uneven.

I plan to fix a couple of thick steel plates to the bottom and side of mine using dowels and counter bored cap screws (drilled and tapped into the body of the table). They will have tenons for easy alignment and reasonable slots for 'T' bolts to match the milling table.

I have studied mine a few times and can't think of a better way to do it.

Phil H

[SillyOldDufferModerator @sillyoldduffer]

Posted by Phil H1 on 06/12/2020 13:56:25:.

…

I have studied mine a few times and can't think of a better way to do it.

Phil H

What a pain. Can you post a photo of your table from the same angle as my first. As the design is similar to mine, it might be possible to file it out to take a nut & bolt.

Once in a Blue Moon I clamp the rear slot to resist toppling pressure but it's rarely necessary – most jobs aren't that heavy and the tail-stock is better if there's room for it.

Dave

[larry phelan 1Participant @larryphelan1]

I thought all rotary tables were much the same. It,s quite clear how that one bolts down, did you not notice the slotted lug at one side and the two bolt holes at the other ?

My table is much the same, although I dont think it has those two small threaded holes, and I have no trouble clamping it either flat or upright. To mount it horizontal, I use an angle plate to make use of that lug and it works fine.

[Howard LewisParticipant @howardlewis46836]

With the surface of the table in the vertical position, it is secured to the table using the two slots visible in S O D's picture showing the bolt in the slot for clamping with the table in horizontal mode.

So there should be no need for external clamping; which occupies space which, one day, will be needed.

Because of the pitch of the T slots on the table of my Mill/Drill, I had to extend the slots, on my Vertex HV6, to enable two M8 bolts to be used for clamping.. This meant clamping the Rotary Table to an angle plate, and setting the surface level, to allow milling to take place.

Howard

[JasonBModerator @jasonb]

I've had a Soba one just like that and never had a problem using it like SoD shows, never had to hunt for a bolt as the one for my vice fit and plenty of room for a standard nut if I wanted to use a stud

[Anonymous]

Posted by SillyOldDuffer on 06/12/2020 14:23:25:

Once in a Blue Moon I clamp the rear slot to resist toppling pressure……………….

Dumb question, but is there a reason for the supporting block being the wrong way round?

Andrew

[JasonBModerator @jasonb]

Posted by Andrew Johnston on 06/12/2020 15:31:56:

Dumb question, but is there a reason for the supporting block being the wrong way round?

Andrew

It is Dave using it

[Jim NicParticipant @jimnic]

As Pete Rimmer, I made a couple of toe clamps like this:

Two clamps hold the RT down just fine.

Jim

[old martParticipant @oldmart]

The two holes in the 6" Soba that I have exactly line up with the tee slots in the Tom Senior, but not the drill mill when the axis is horizontal. In addition, I have drilled and tapped the base to hold a small angle plate for extra stability with a three point holding system. The slot on the end shown in the second photo has been milled deeper to fit the 1/2 UNC tee slot fixings for the mill drill. It is not difficult to modify tooling to fit and work better, although some people with machine tools are terrified of doing so, as if actually using the machinery was a bad thing and painting and polishing it was all that was needed.

[SillyOldDufferModerator @sillyoldduffer]

Posted by JasonB on 06/12/2020 15:44:24:

Posted by Andrew Johnston on 06/12/2020 15:31:56:

Dumb question, but is there a reason for the supporting block being the wrong way round?

Andrew

It is Dave using it

Yup…

Dave

[Clive FosterParticipant @clivefoster55965]

Seems to be a rotary table designers union rule that the slot be too shallow to take a clamping kit nut and the lug too short to accommodate a washer leaving the bolt head (almost) overhanging outside. My high grade professional10" and 12" tables suffer just as much as the hobby grade Vertex 8".

Objectively Jims toe clamp is the best solution.

Alternately a thick washer of L section used with the overhang of the thick side butting up against the RT body would give a better seat for the bolt head.

Some time in the next 20 or so years mine might irritate me enough to "do something" but right now such improvements are firmly filed in the "life is too short" drawer. Which currently re-defines way overfull!

Daves first picture looks just like mine do.

Clive

[Phil H1Participant @philh196021]

Dave,

Yes I'll take some later and post them provided nobody feels I'm stealing the thread. Mine is quite a challenge.

Phil H

[JasonBModerator @jasonb]

The alternative is to buy a R/T that comes complete with clamps and even the locating blocks (and screws) that screw into the slot. Nice of Uncle Ketan @ ARC to include them Their tables also have a good long slot so you can be sure that a clamp will fit no matter what your tee slot spacing is, I tend to do them diagonally opposite so the clamp on the far side is in the rear tee slot.

Edited By JasonB on 06/12/2020 18:50:49

[Roger BestParticipant @rogerbest89007]

I do like those toe clamps.

I have a large turntable, (missing its worm gear, which is why I have it), that has two featureless pads sticking out the side. I think its simply a clamp-down job. It does seem bizarre. It won't be out for a while, far too much to do.

[Phil H1Participant @philh196021]

This is the top view of my table and there are no slots in the sides. You can see that any 'land' to put a small clamp 'nose' is rather limited and even the surface of any land is rough 'as cast'.

There is a slot in the bottom of the table that I can use when the table is turned by 90 degrees (spindle parallel with the milling table)- so I could make one of the handy clamps already posted for that orientation. Please forgive the swarf by the way.

It is not the best table for a number of reasons. For example, I think I would prefer 4 tee slots on the table top rather than 3. But I am not complaining. It does work for the work I have done so far and it was 'CHEAP'. It was probably cheap because nobody else could figure out how to hold it down to a milling table.

[SillyOldDufferModerator @sillyoldduffer]

I see the problem now. Not like the usual Vertex style table is it! It can only be clamped, and not easily. Hard to see what the designer was thinking.

Toe clamps seem the only option unless suitable holes can be drilled through the web. But I bet they won't match your table slots.

I'm stumped.

Dave

[Anonymous]

Posted by SillyOldDuffer on 08/12/2020 15:22:45:

Hard to see what the designer was thinking.

Always assuming that he was, thinking that is.

Andrew

[Clive FosterParticipant @clivefoster55965]

Phil

In your position I'd fix the table to a small baseplate with overhangs for clamps or lugs / holes for bolts / studs suitably positioned to match the slots on your mill table. Alloy plate, around 1/4" or 3/8" thick held on by 5 or 6 mm c/s socket head screws in tapped holes will be fine for a base plate. You will have to strip the rotary table to find sensible homes for the tapped holes but that shouldn't be too difficult and will give you the opportunity to verify the condition of the internals and state of lubrication.

If you choose to copy the excellent toe clamps supplied by Arc and shown in Jasons picture do be aware that this style of clamp has a rather nasty inherent gotcha that can mark or even damage your mill table if appropriate precautions aren't taken.

The nature of the clamping action means that they have to pivot about the opposite end from the holding down toe. Which produces very high forces on a small area at the end. Not good for nice tables. I've not seen a mill table with significant damage beyond cosmetics from this but I have seen the top of a optical table dinged. Not a good thing to do to £20,000 worth of Ealings finest!

Simplest answer is a piece of packing under the tail but that upsets the geometry a little and the shop gremlins tend to hide the just the right size piece. I prefer to make them flexure style with a short, thicker part at the end to sit on the table with the rest thinned down by 50 + thou / 1.5 mm or so allowing it to bend and apply force to the toe. If you make it right size it doesn't have to flex much for a very decent grip. Fancy folk use a part cylindrical section washer under the bolt for cleaner flex, which is going a bit far.

I generally use light alloy for clamps, tee nuts and other table contacting accessories. Any swaf that gets underfoot tends to be pushed into the alloy rather than damage the table. Alloy is plenty strong enough for Tee nuts, if you strip one you are overdoing things, and no one has yet figured out a way to completely clear all swarf from the table slots so steel ones will eventually mess the underneaths up.

Clive

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