Using a pillar drill for milling?

[Nigel Graham 2Participant @nigelgraham2]

I'm afraid you won't find a reasonably -sized milling-machine made in the UK now.

My own is a Myford VMC, but that was made in Far East and Myford no longer make them, unfortunately, Inaccurately described by Myford itself as a "turret" mill, it stands roughly 6 feet high with its belt-cover open. That's on its proper stand. it's decent-size machine that will handle most model-engineering and similar projects easily.

Most except the smallest milling machines are made to fit on a purpose-made stand, not on an ordinary bench, as that's not rigid enough, though the stand is often offered as an extra ..

They do a need a good rigid base. My present workshop has a concrete slab floor, which is ideal; but my previous was an ordinary wooden shed which I lined for insulation. To stabilise the milling-machine I had then, a Warco " mill/drill " on a substantial frame made by its previous owner, I cut 4 holes in the timber floor and cemented brick pads to the concrete foundation, with interposed plastic discs to act as " damp-proof courses ".

A lot of stuff coming from the Far East is of doubtful quality, but the main model-engineering suppliers in this country are careful to import the better machines. You may need to carry out quite a bit of setting-up, starting with cleaning off thick antic-corrosion goo, but the importers will tell you how to go about it.

'

To amplify Dave's comments, a Jig Borer proper is a large, very highly specialist machine but the sort you and I are most likely to encounter (and I own one) is the compact but massively-built BCA, sold by Tenga Engineering. It's not really a "jig-borer" by principle, but is a small, precision vertical-mill whose long-travel table is basically also a rotary-table; but " long " is relative here: under 8 inches I think. Its main use for us would be making very small components with a lot of radius-based features. For most purposes a conventional vertical milling-machine, on which you can mount a rotary table anyway, will be much the better choice; and will handle those very small components easily.

'

So your best route is

1) Decide what sort of projects attract you, to gain an idea of the sizes of their largest components hence the machine capacity needed. Note that table size is usually smaller than travel.

2) Examine what's on offer, new or second-hand; but note Dave's comments on condition and spares availability; with reference to Point 1) as well what fits your workshop.

3) Again from 1), determine what tooling you will need to hold milling-cutters and a drill-chuck to start with. You can add nice things to have, like a boring-head, later.

Also what work-holding. A drill-vice is not suitable for milling as it is too lightly made, but there's no reason you can't use a milling-machine vice on a pillar drill if it fits the table. A milling-vice is a precision-tool with a hefty body sliding usually on dove-tails, as it has to carry heavy lateral loads, and the larger sizes are very lumpy beasts.

First and foremost though is a clamping-set with T-nuts and studs appropriate to the machine – and you will soon find you can never have too many clamps! Harold Hall's Milling book (Workshop Practice series) has a lot of advice on safe work-holding.

You can add angle-plates, a rotary table etc. later. but these greatly enhance the range of operations possible.

It will be worth your finding someone who can traipse around a major exhibition to examine machine-tools with you… though I gather one of the largest suppliers, Warco, has announced it is no longer attending the shows.

(BTW… your drill, is it a Pillar drill, or a Bench drill? The difference is simply that the Pillar Drill's column is very much higher, rising from a heavy base that must be bolted to a flat, level and solid floor. The Bench drill has a fairly low column and is made to be bolted to a rigid bench; even if the head is identical to that on the same maker's equivalent pillar-drill. The advantage of the pillar-drill is much greater height-range for the work.)

'

Finally I think you asked about lathe change-wheels. Yes, they are for fine feeds as well as screw-cutting, depending on the range of wheels your lathe has.

Books on turning detail the calculations, but I can show the principle by example. Say your lathe's lead-screw has a lead (= travel of the saddle per revolution) of 1/8 inch.

If you connect the spindle to the lead-screw by gears of overall ratio 1:1, one turn of the spindle will turn the lead-screw 1/8 " so moving the saddle 1/8 ". For cutting an 8 tpi thread (tpi = threads per inch).

Double the ratio denominator to 1:2, the lead-screw rotates half a turn, the saddle moves 1/16 " – a 16tpi thread.

1:4 = gives 1/4 of the lead, 1/32 " travel: 32tpi (a standard Model Engineering Thread-count).

And so on. Eventually, with a compound gear-train, the lead-screw turn is such a small fraction per turn of the spindle that it moves the saddle only a few " thou " per spindle revolution, giving a good though not necessarily satin-sheen finish (assuming all else being just so!).

I think the finest listed on my Myford 7's change-wheel chart is 0.004 " per spindle rev. This probably matches a lot of reasonable trade turning where the surface is be tidy but not critical to function.

( Lathes don't like being over-driven to cut, say, a 4tpi thread, by the way.)

Eventually, assuming you have the change-wheel

[Chris VParticipant @chrisv]

Thanks Neil, oh ok, add that to the rest of the stuff I didnt know! (-:

Cheers

Chris.

[Chris VParticipant @chrisv]

Thank you Bill & Silly Old Duffer, seems like I'll have little choice but to go Chinese, still think its a shame though.

Cheers

Chris.

[Chris VParticipant @chrisv]

Thank you Nigel G2. Well if I want one it looks like it will be imported and small, I only have one available place for it and that's at one end of my workbench. Whist the bench is substantial I take on what you say about rigidity etc but I'm restricted to the bench only. My drill is a bench top model. Yes I had looked at the BCA's and agree it sounds like its not ideal for me. Yes I was looking at Warco's offerings, I could get to their showroom ok to see first them hand. Looks like machine size will more determine what I can and cannot take on to mill, but I have to start somewhere. Having a modest capability rather than none will help guide me as to what I want to end up machining, most likely stationary engine kit/s. I wont be rushing into buying that's for sure.

So I had to look up what DRO meant, ….as its available on new machines is it now considered a must have?
On the down side it adds around a third to the cost of the small machines and is no doubt another thing to go wrong.

That said I didn't want digital calipers as I knew the batteries would run out and they would likely go wrong…Well I was right but that, but I'm so grateful I can see the display to read what I'm measuring!!!! (-:

So maybe the same holds true for DRO?

Cheers

Chris.

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[Chris VParticipant @chrisv]

Regarding the milling, also metric or imperial??? I'd probably find metric easier to get my head around than fractions of an inch, but would be interested in your thoughts?

Cheers

Chris.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Chris, something you can only answer yourself really, and if your not that good at imperial measuring, I would think is easy to solve.

Regards Nick.

[SillyOldDufferModerator @sillyoldduffer]

Posted by Chris Vickers on 27/06/2019 11:15:47:

Regarding the milling, also metric or imperial??? I'd probably find metric easier to get my head around than fractions of an inch, but would be interested in your thoughts?

Cheers

Chris.

I'm metric, partly because I have scientific interests, partly because metric is easier and less error prone because it's internally consistent and eliminates unnecessary conversions in the maths.

Two main reasons I would have gone Imperial:

1. Someone offered me a good deal on a second-hand workshop in good condition!
2. I intended to specialise in making stuff to Imperial plans, or scaling models from imperial prototypes, or refurbishing imperial equipment.

A third valid reason for preferring imperial is having a lifetime's experience of imperial measure. Not many youngsters in this group, unless you are an American! (And even they are gradually going metric.)

The tide in the UK is running against buying stock and tools in Imperial sizes. Not a major problem yet because a lot of Imperial is still about. But, in broad terms metric tends to be cheaper and easier to find. Some older Imperial systems like Whitworth are no longer mainstream, and only available as 'New Old Stock', to special order, or is even Unobtainium. Doubly difficult to be imperial in historically metric countries.

Worth putting a little thought into what your workshop is for. Far Eastern metric equipment suits me because I like learning and I mostly make metric objects. I see tools as consumables, to be used rather than cherished, Others like to celebrate traditional techniques and enjoy well-made British tools as icons. At one side of hobby are chaps embracing computers, CNC, cheap foreign tools, and experimental work (aka bodging!). At the other are chaps who making superb steam locomotives from LBSC plans with 50 year old manual lathes, where skills and quality are relished.

Most of us I suspect are in the middle, mixing tools, techniques, and outputs to suit our interests and budgets. In the end, it's your hobby, so spend money on what you want. My main regret is not getting stuck in earlier due to indecisiveness. Too much conflicting advice! Eventually I realised that flashing some cash on Far Eastern kit (a mini-lathe) would get me started with minimum bother. Not the best of all possible lathes, but I had lots of fun and learned a great deal from it. For me, cutting metal today is more important than setting up a top-end workshop in the distant future. I'm messy, care minimally about finish, and potter. I will never win any medals! What's your intent and ambition?

Dave

[not done it yetParticipant @notdoneityet]

Hi Chris,

My mills are old – 1960s. A centec 2B and a Raglan. The Centec can be used for either horizontal or vertical milling, so is quite a popular model among hobbyists, but certainly not a light machine.

[Nigel Graham 2Participant @nigelgraham2]

I owned a Centec 2B for a while, even fitted it with a raising-block from Tony Griffiths.

"… not a light machine.. " in weight, I agree. It is a good little machine, and it will fit on a strong bench, but its capacity is quite small.

If I were looking for anything similar now, I think I'd investigate the smaller Tom Senior or equivalent mills.

As it happens I have a Denbigh H4 horizontal mill, but it's quite basic and not designed to take a vertical head. I think people have made such heads for similar machines, but it's a lot of work and the base machine's flowing curves don't exactly help.

[Chris VParticipant @chrisv]

Thank you Nick, Dave, Not done it and NG2 I will investigate further.

In terms of my work I'm used to BA, BSB & Whitworth threads, though I normally use metric drills. I find most of my raw material suppliers still supply Imperial sizes. But measuring myself anything under 1mm my metric digital calipers come into their own…referal to conversion charts for drill sizes etc is frequent.

My lathe the old Myford ML1 was bought on grounds of size, ie small, basic, and looks, I like old tools & machinery. I am gradually learning the basics of how a lathe works and what does what, not that its running yet. Before buying I was aware a ML10 or ML7 is much more sophisticated and up to date but I felt it better to start basic. Someone mentioned Drummond treadle lathes I think, I was SO tempted but being tall I figured I'd bang my knees and maybe that was a step back in time too far, oh and space was against it too, I can store stuff under the Myford.

Apart from the general ability to turn steel (I hand turn brass on my wood lathe) the aim for me is to be able to make a stationary engine kit such as a Stuart Turner James Coombes. I started one years ago and put it down when self employment work took over. By started I mean I did some basic work like chain drilling and cutting out apertures in the plate steel, filing up castings and taper turned the 4 columns on my Unimat SL. Leaving the tricky stuff….

A few years back I gave it away to a relative to finish but hes not touched it so I might be able to get it back, if I don't I'd like to build something like the Polly Benson engine kit. But I don't have a mill and can see a dedicated machine would be better than trying it on my basic lathe. So I then looked at German Bengs kits, as they don't need milling, its already done. But they use metric threads of which I have very few, though I guess I could use imperial.

I expect the S Turner kits specify any milling required in imperial but I don't recall? That why I asked about metric or imperial, in a nutshell

Cheers

Chris.

[Neil WyattModerator @neilwyatt]

Posted by Chris Vickers on 27/06/2019 16:34:20:

I expect the S Turner kits specify any milling required in imperial but I don't recall? That why I asked about metric or imperial, in a nutshell

Cheers

Chris.

I recall that ST kits have dual dimensions on the plans these days? I may be wrong, it's a long time since I made my 10V.

Most of the ST kits can be made on a lathe alone, any milling is generally do-able with the work attached to the toolpost, or even by careful filing and checking against a flat surface.

Neil

Edited By Neil Wyatt on 29/06/2019 12:47:27

[Chris VParticipant @chrisv]

Thanks Neil, I've ordered some books and past ME issue CD'S and will take some time to process what's next.

Cheers

Chris.

[Chris VParticipant @chrisv]

Thanks Neil, I've ordered some books and past ME issue CD'S and will take some time to process what's next.

Cheers

Chris.

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