Rotating and Dividing on an ML7 – BS-0?

[William AyerstParticipant @williamayerst55662]

As per post in the TE subforum about my current setup of … just an ML7 – and the recommendation that for things like gear cutting as well as larger machining work, a mill is very useful.

Ultimately I think a mill, linisher, and drill press are in my future. I now realise the advice on here and elsewhere to get the biggest lathe I could handle was spot on – I'm already thinking that a few extra inches of swing would be useful – and I don't want to make that mistake with my (future) mill – so it will likely be a costly purchase and one taken after serious consideration.

With that in mind, I'm considering my options in the meantime – while RDG and Chronos do small rotary tables with chucks for about £120is to fit on a vertical slide. I'd really rather not buy cheap chinese guff, and it would appear that this is entirely a tactical solution – as once I've got myself a mill there would be no reason to use it over a larger and more robust setup.

The main thing I'm looking at is a Vertex-style BS-0 which both Chronos and RDG also supply – with indexing plates, tailstock, etc. etc. for about £330. This seems like something that could be used in a mill in future, but I'm not sure if it would fit on the ML7 cross slide?

Any thoughts or opinions gladly taken,

[William AyerstParticipant @williamayerst55662]

[Martin KyteParticipant @martinkyte99762]

I think the most usefull thing you could do is build the George Thomas Versatile Dividing Head. It will fit nicely on the cross sile at centre hight and on the vertical slide. You can make the basic version to start with with the option of going the whole hog at a later date. If you decide to make the Headstock dividing attachment in the future the plates, mocro adjust and some other bits are interchangable. And it was designed for the Myford.

I use mine far more than my rotary table which I would only use on the mill anyway. IThe rotary table can go several years between uses whilst the GHT head gets used at least every month.

It's a good excercise too with the Hemmingway kit and a full write up.

regards Martin

[William AyerstParticipant @williamayerst55662]

Thank you Martin – this sounds like a silly question but can I build it with just the ML7 with a vertical slide? I don't currently have a drill press (although I do have a drill pad for the ML7 tailstock and a hand clamp so can do a little drilling that way, in theory)

[JasonBModerator @jasonb]

I would say 99% of Minnie builders buy ready cut gears and that is how the original was designed to use off the shelf gears. So unless you specifically want to make them there is no real need to have a dividing head or rotary table, Mason describes ways to do the work without their use.

[William AyerstParticipant @williamayerst55662]

JasonB thank you – I absolutely did not know that and certain makes that less of a pressing concern. May I ask what book I'm after which describes the construction/drawings/etc. please?

[HopperParticipant @hopper]

That's true. You can buy metric gears stupid cheap on Aliexpress etc these days, including worms and wormwheels. Even if original plans are imperial, you can adapt the nearest size metric module I should think.

But if you wanted to make your own Versatile Dividing Head as a project, yes it can all be done on a ML7. I made mine on a 1937 Drummond M-type that is the same size lathe. Used a Myford vertical spindle for some of the milling and gear cutting. But it is a fairly extensive project all on its own and not really a beginner project, although it could be with suitable care.

There was a recent thread on BS0 type dividing heads for Myfords and it pointed out that the BS0 was too big to work on the necessary vertical slide. Centre height is way too much. The VDH is only about 2" centre height.

Edited By Hopper on 16/03/2021 10:01:24

[Nigel Graham 2Participant @nigelgraham2]

I would concur with Martin here.

The Vertex-copy BS-0 (as I own, with Warco's name on it) won't fit a Myford lathe, certainly not the vertical slide, nor is it meant to. Even if you made it fit the cross-slide, its bulk and centre-height will limit its use very severely.

Dividing-heads like that are meant as milling-machine and bench-drill accessories, and the Vertex-sizes are heavy, bulky items that occupy a heck of a lot of the available height between spindle and table.

You need a dividing head or rotary table designed for the class of machine that will accommodate it – such as the Geo. Thomas.

'

How much you use either dividing-head or rotary-table depends very much on what are making. They do different things, with some overlap; and many rotary tables, like mine, are made to be used flat, on a mill. You can use an RT for dividing to defined angles; but not use a dividing-head for arc-milling unless it is built for such duty.

I made a pair of T-slot inserts to locate my Warco "Vertex"-copy and its tailstock directly on my mill. One thing Waroc specified is that its version will take Myford chucks.

Adding to the ER collet set I bought for my ML7, I also bought a square and hexagonal Stevenson's Blocks with ER spigots, as a large proportion of common dividing work uses just 2, 4 or 6 divisions.

'

I can vouch for Hemingway's kits, having started with (but not yet used!) their between-centres boring-bar set and now nearing completing their 'Worden' tool-&-cutter grinder.

[Martin KyteParticipant @martinkyte99762]

Posted by William Ayerst on 16/03/2021 09:42:29:

Thank you Martin – this sounds like a silly question but can I build it with just the ML7 with a vertical slide? I don't currently have a drill press (although I do have a drill pad for the ML7 tailstock and a hand clamp so can do a little drilling that way, in theory)

Hi William

The dividing head can be built with what you have. The vast majority of the operations are either turning, face plate work (for which you will need a small angle plate or drilling, boring or facing in the saddle or vertical slide. You may like to obtain a copy of Workshop Techniques by Geo. H. Thomas which has a full write up of the VDH and the headstock attachment and the pillar tool and is an interesting and informative read in it's own right.

Access to other machinary whilst helpfull is by no means vital, for example he shows a bandsaw being used to rough shape a component but a hacksaw does the job equally well.

regards Martin

[JasonBModerator @jasonb]

William, see you other post for the link I posted, the articles are basically what is printed in the book "model traction engine building featuring Minnie" by LC Mason

[William AyerstParticipant @williamayerst55662]

Perfect – so VDH if required since BS0 is too big, otherwise bought in gears. I'll check the thread for the link also – thank you all very much.

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