Member postings for Nigel Graham 2

Thank you Colin.

I remember seeing that edition of the course mentioned, yes.

Not only a readable size as-is, but can also be enlarged a bit further by the normal screen controls (as I have often done with pdf documents.)

I doubt I still have the link as I no longer have the original trial version, but although the Alibre short-cut's there on the screen, trying to open it fails immediately with a Licence Expired message.

I re-loaded it yesterday to avoid operating-system problems SillyOldDuffer warned me may occur by my having merely deleted the programme, rather than removing it properly. (I'd forgotten where to find the control.)

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BTW I had an amusing moment when I followed that CAD/CAM link JasonB posted a few message back. I have set my PC's protection fairly high, but I'd not bargained for making a model water-pump to arouse the "BT Parental Controls" into asking if I wished to authorise my reading it!

Thank you.

I remember the Viewer-only limit being stated, possibly in MEW. I did follow the first instalment in the magazine, but I have deleted the resulting file.

Though I had found by experiment how to enlarge and recess that scribing-block's base similarly to a real one I own, to make it more stable!

I lost heart after missing two editions of MEW despite being sure I'd specified my first subscription issue correctly, at the same time as meeting big, insoluble difficulties with TurboCAD. I had bought the first edition in WH Smiths, on the strength of the Alibre ads in ME magazine; thinking with the serial as well I'd find Alibre Atom simpler to learn.

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.

Thank you Michael.

Yes, my error.

FIVE BA is of 0.126 " diameter.

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I quoted the Imperial sizes of BA threads to cater for measuring these parts in both, and directly from a text-book giving both scales in one table for the same reason.

BA is metric but so different from the ISO-M range only one or two sizes are vaguely close together, and then only by coincidence, not proper fit.

I wondered as an exercise if they could feasibly be screw-cut on my Imperial lathes. Using a spread-sheet (whose absolute reference function really comes into its own for such things), I managed to produce some fairly close change-wheel combinations for short threads before the cumulative pitch errors become too large. They'd still need finish-profiling by die,

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I'm not yet gardening fit, and my lawn (using the term loosely) is becoming a hay-meadow with lots and lots of flowering grasses and their seed-heads. Managed to trim the front-garden buddleia yesterday, before its low-growing branches closed the pavement to anyone over three feet tall.

Advice taken. Thank you chaps.

I can't use it because the licence has expired, but at least I shouldn't have those problems.

And it is there if I have a change of heart, though I know that will be expensive.

It's certainly not 5BA, whose o.d. is very close to 1/8 inch.

(8BA is actually 0.126 " full diameter, and a lot of model designs specify 1/8 " dia rod for 5BA studs, so within tolerance.).

I still think 7BA but I'm surprised an 8BA nut will fit.

SO

7BA 0.098 " full dia, pitch 0.019" : 2.5 mm 0.48mm respectively.

8BA 0.087 full dia, pitch 0.017 " : 2.2 mm 0.43mm " "

Diameter measured: 0.085" (2.16mm)

Pitch from the photograph, very slightly <0.5mm

Inch values rounded to 3 dec. places from 4-figure tables. The sizes look odd because the full BA range is a metric geometrical series.

If it's none of what anyone's suggested it can only have been some non-standard thread of the maker's own.

Does anyone have a spare 7BA nut they can give, or a 7BA tap they can lend, to Nearly Done? (I might have a tap, but not a nut.)

Still tottering about on crutches but I managed, with great care not to put any load on my "done" leg, I moved enough rammel around in the workshop to put an adjustable medical-type stool in front of the lathe.

So hopefully I might be able to make a bit of swarf in the next few days or so!

This is a rum 'un....

44tpi is not a standard Whit-form thread. Studying the Mechanical World Year Book 1957, and your supplied information, I reckon the following:

It's actually metric but not from the modern ISO Series.

So:... 7BA? BA is in fact metric, based I think on the old, Swiss Thury thread.

OD for 7BA = 2.5mm. Pitch = 0.48mm.

Enlarging the page to read the photo better...

Pitch by the rule: a gnat's crochet under 0.5mm.*

Dia. measured = 0.085 " = 2.16mm but could be accounted for by over-rounding when cut, and by wear in service. The thread does look as if it's seen a year or two.

So I reckon the nearest standard to the photographed screw is 7BA.!

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(Long-time listeners to I'm Sorry I Haven't A Clue will know that unit of estimation...)

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.

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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.

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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.)

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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

Thank you David.

Even if in fact I decide to leave installed, it should at least remove the risk of the difficulties SillyOldDuffer cites.

Jason -

My thoughts on availability come from reading the publishers' web-sites, which don't mention costs but certainly don't mention private sales. There are companies in all sorts of areas that sell to the trade-only, so I took it these software firms are the same.

Jason -

I am impressed! I can still appreciate the skill involved even though disappointed by my attempts.

I've know for a long time you can make machine-control files from CAD drawings but I hadn't known you can translate even images like that catalogue engraving into the CAD drawing to start with.

I read their remarks about the distortion given by the angle of view, and so used known vertical heights to start establishing the correct horizontal dimensions.

I don't think the SolidWorks and AutoCAD they used are available to private customers in the UK, but I imagine you can use Alibre or Fusion for similar? (Fusion and AutoCAD are by the same company anyway.)

I first met CAD as SolidWorks, at work, but just by observation not experience; around the time TurboCAD was being advertised in ME. It was there too that I encountered the practice of putting a pictorial rendering in the corner of the orthographic drawing, to help visualise the work-piece. Hemingway Kits follow the same practice.

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SillyOdDuffer -

Thank for you for that advice. I found "Uninstall " eventually. However, it could not remove Alibre because it could not find what I assume are Alibre components. I tried to repair / recover the programme to uninstall it properly, but to no avail.

So I am stuck with a programme I wanted gone because I could not use it, but I've now damaged so badly it cannot be used, repaired or removed anyway! I will have to hope it just lies there and causes no trouble.

I don't know if this will work or be at all possible, but I'd wondered about re-loading so it sweeps up or disables any intact fragments it can find, then uninstalling it properly. A bit like using new oil to remove dried-on oil. Unfortunately I doubt I still have the last Alibre e-post that offered it.

Thankyou Tom.

I didn't know you can do that!

It's not something really covered in the only two CAD "primers" I have found anywhere, by DAG Brown and more recently, Neill Hughes; and sold by our very valuable specialists, TEE Publishing

I don't think Mr. Brown describes it at all; whilst Mr. Hughes tells us more what can be done than how to do it. His example of using a scanned 2D drawing to guide the CAD version seems much as you describe, and he notes the value of the original drawing's scale-bar.

Hughes also mentions 3D scanning, but only briefly and fairly clearly as what's done industrially. In fact his book's sparse bibliography lists only reference-works for professional designers and production-managers. Having said that, versions of such books written early in the 20C are very useful when trying to replicate an Edwardian machine without its original drawings, for showing contemporary practices, component proportions, etc.

If really stuck I have sometimes gauged details by parts that need literally be measured in "hands" (well, the machine develops or absorbs 'horsepower ' ... ) and other anthropocentric proportions, such as handrails, steps and the grips on the ends of levers. Essentially, think in likely full size, and how it was operated, first.

Barrie -

I asked about scanners following your remark about photos.

That could have even helped my own project, as I have nothing but old archive photos and a few dimensions.

The big difficulty though, is a photo is usually at unknown angles to its subject, and from an unknown distance, so simply scanning it would give a distorted result. If the subject is long, such as railway locomotive or a building, the photo may also be affected by perspective.

I recall an article a long time ago, I think in ME, that described how to correct for these manually, provided you know a few key dimensions. For the locomotive this may be the coupled-wheel diameter (by its height, if all visible) and track gauge.

For my wagon, I used the wheel diameters and overall length and width, quoted in old trade reviews, but to make it more fun, E.S Hindley & Sons did not appear to worry too much about standardising theri products, and the reviews' illustrations were not necessarily of the wagon the reviewers test-drove!

I don't know if the software you describe can correct for both of these distortions.

As far as I am aware, TurboCAD doesn't read scanner files, which are images types at least from my scanner; but I think it will accept other drawing files. Its default saving is in its own " .tcw " format; but you can save its fully-rendered pictures as .bmp (and .jpg?) images.

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Alibre's sales people don't seem to talk to their agents, but they do want you to buy their software!

A lady from its own American offices no less, asked me yesterday how I was progressing with the trial.

I replied I had failed; explained why, and that as the trial and its licence have expired I'd now have to buy the full version but it would be silly to spend £250 on something I can't learn! Then added I had already deleted Alibre from my computer ("Deleted" it, files and folders, as I could not remember how to "uninstall" it.)

I'm not expecting a reply of course, but I would not surprised if she tries to persuade me otherwise, since she is paid to sell it.

All very well but there will still come a time when the old batteries are beyond use, so what then? How recoverable are their materials, including the case, which I assume are some form of plastic?

Y4es,. we can only admire the quality many of them achieved with very basic equipment.

For decades they were doing well to have a treadle-driven Drummond lathe (which was quite a versatile machine), a hand-operated bench-drill and hand-operated grinder.

Early-20C Model Engineer & Electrician as it then was, is a treasure-trove of ingenuity - I've seen in one copy, even how to re-seat a kitchen tap before the days of tap re-seating tools. (On the lathe, of course.)

" Thinking of space(lack of) I suspect for reasons I don't yet know a milling machine dosen't make a good drilling machine either? Perhaps they don't take Jacobs type chucks.... "

Ah, now, you CAN use a milling-machine as a precision drilling-machine; co-ordinates and all.

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In fact a typical milling task may involve drilling and tapping several holes as well as squaring the outline to shape and size, cutting slots etc., all in one piece of metal.

No, they don't take Jacobs chucks directly in the spindle. Instead, the chuck fits onto a special adaptor with the Jacobs nose and an appropriate taper shank with internal draw-bar thread to fit the spindle; and it stays on the adaptor. You remove the adaptor from the mill, not drill-chuck from adaptor.

Just make sure you don't spoil the machine by drilling too deep and into the table!

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Milling-machines generally don't have a chuck as such, like a drilling-machine. Instead the cutters, drill-chucks etc are held by interchangeable tooling that fits into one of various standard types of spindle taper. The two standards you and I are most likely to encounter are:

Morse (MT3 being perhaps the most common for model-engineering milling-machines).

R8. This was the standard on Bridgeport milling-machines once very common in the engineering trade, and on the Myford VMC mill. (The one I have)

You might encounter ISO - number; the modern industrial standard particularly suited to high-performance CNC machines. I don't know if any of the model-engineering trade machines use them: some of the larger, latest might.

New and second-hand Morse and R8 tooling is quite easy to find. The advantage of R8 is that the taper is steeper than Morse, so much less likely to jam in the spindle; but Morse tapers means some tooling is interchangeable with other machines, like most small lathes.

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You can also add to milling-machines, accessories like vices designed for that task, rotary tables for cutting arcs and drilling accurately-spaced rings of holes, and angle-plates which at their simplest hold a work-piece on its side.

On-line catalogues like those of Arc Eurotrade have photos of milling- (and other) machine tooling, as examples.

May I ask why you want an ER chuck on a drilling-machine? To hold a milling-cutter?

Also, though I don't know your particular example, most drilling-machine spindles do not have through-holes so you can't use a draw-bar in them; but many have MT spindles with an internal slot to drive a drill tang.

Everyone's been advising you NOT to use a drilling-machine as a milling-machine, even below 10mm dia cutters. It is NOT made for it, and would a recipe for disaster. The only thing you can use a milling-cutter for in a drill, is to complete a counter-bore first partially drilled to that diameter .

Neither is a co-ordinate- or cross- vice a substitute milling-machine table. Nor is it like a lathe cross-slide, which is designed to take the sideways loads in turning. It is a small drill-vice on top of a slide mounted in turn on another, used solely to move the work-piece between drilling each hole; and taking downwards pressure only. Many of them are very lightly made and of very limited travel anyway. Note what I wrote above: it "... may seem the answer but it is not..." (for milling).

To convert a drilling-machine to a basic mill is possible but only with a lot of precision-engineering, not least including a heavy-duty radial bearing located accurately on an arm fitted to the column to take all the side-loads off the spindle and its bearings. Then you would need a co-ordinate table capable of absorbing milling-type loads.

I admit I got away with a cutting a short arc slot in a bit of plastic sheet, but a rotary-table IS a milling-machine accessory, and I was taking only very light cuts in a very soft material. I also said it was a quick solution to an immediate problem, and I do NOT make a habit of it.

You could build a basic milling-machine, but it's a lot of work. To add to what Larry Phelan said, you are better buying a new or decent second-hand one as large as you can afford by both room and money.

Don't go for the round-colum types though because you have to re-set the centre alignment every time you move the head up and down the column, sometimes several times in making the same part. As I found out! Fortunately there are now available even quite modest milling-machines with dovetail columns, and many people seem to find them very satisfactory.

I tried a simple test with a 300mm Vitrex TC "blade" this afternoon.

With end fittings rather like wire crimp terminals it fitted the hacksaw easily, but would need a short slot cutting if used entirely within the material.

It had no problems with an oddment of RHS steel angle 6mm thick, but as it is abrading its way with a kerf of perhaps 4mm, it's not the most efficient method.

It had no problem with a small scrap of aluminium-alloy bar, apart from a bit of clogging.

I tried it on the back end of an HSS lathe tool, with a view to suitability for roughing out a form tool, or cutting a length of tool-steel to make a boring-bar bit. Starting the cut neatly was hard because it skidded all over the place, but eventually I made a groove perhaps 6mm deep before stopping - no point wearing the blade further. An angle-grinder with a cutting-disc would be the better choice, and a lot cheaper.

So these abrasive tools are better than nothing, but not ideal replacements for round tension files for making cut-outs in metal plates.

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Anyone tried the Bestway files yet?

Unless you wish it to be "proper" wood, you could use a good-quality plywood. Sand all the edges and give it a thorough sealing with polyurethane varnish or similar.

The problem with oak is that it is rather acidic and corrodes iron and steel.

My past employers used to use a lot of special-to-contents boxes, and some of these were lovely examples of plywood art, with some parts like equipment cradles laminated plywood-on-plywood enabling ready inclusion of rebates and flanges; and all heavily treated with exterior-grade varnish. I used similar techniques for parts of the computer desk I am typing at now!

Thank you for that last paragraph - it seems to bear out my thought why Alibre was preventing me using even the trial software it was still sending.

I'm pretty sure I had used "Uninstall", but when I tried again it put up a message about "Repairing", hence my thinking Uninstall is similar to Delete File.

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Otherwise,.....

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Oh I Am Sorry I Spoke in such august company.

Don't worry, I won't ask about "licensing (or anything else)". A forum at a level obviously beyond anything I could achieve, is clearly not my place.

I will remove Alibre from my computer; and will not renew my MEW subscription which I purchased originally for the Alibre offer. (I may keep buying ME, as I have done for many years.)