Member postings for Nigel Graham 2

They may well have had some form of very simple lathe, even if the motive power was an assistant turning a handle, or it was perhaps a pole lathe.

The basic concept of turning, in wood, seems to have been used by the Ancient Egyptians; with an assistant revolving the work-piece directly. The Romans used simple, probably pole-, lathes for furniture making.

As for tools, did the Ancient Greeks have iron? Or could they have used knapped flints in suitable holders to cut the relatively soft bronze? (Flint is silica, I think harder than tungsten-carbide!)

Artefacts from the Bronze Age often show engraved patterns and other examples of cut work, so having discovered how to make the alloys in the first place, the ancients don't seem to have taken too long (historically) to develop methods of working them into items often both functional and aesthetically beautiful.

I have a small earthenware bottle of the stuff, too. There must be something I can use it for. Unless there are specialist metals dealers who will pay more for it than the cost of my taking it to them.

Sorry - I did NOT intent that stupid 'wink' sign.

I forgot it appears from certain punctuation marks and I can see no way to edit it away.

Edited By JasonB on 04/06/2019 16:13:52

Neil -

Thank you for your good wishes! I received the letter today asking me to make an appointment with the physiotherapist.

'

Doncaster Racecourse: easy if you know the area. I don't. Very busy roads, many large, complicated junctions, few sign-posts. Having to concentrate on fast-moving, heavy traffic while trying to listen to the sat-"nag" I dare not read, looking for any signs that did exist; counting confusing roundabout exits. In such conditions the sat-nav cannot keep up, so becomes very ambiguous. It did lead me there, but via a trading-estate and the rail-freight yard.

The car-park was signed "Full": had to cross that very busy urban dual-carriageway and look for the alleged "Overflow" car-park - no signs, either for or of.

Finally, in one last attempt before giving up and driving on to the Dales, I came round that big roundabout once more, spotted a single space in the car-park and succeeded in getting in.

Public transport? Excepting I needed to drive elsewhere that weekend anyway. The North of England is very easy to reach by train from Weymouth (via Bristol), but distance and times would enforce a prohibitively costly two nights' accommodation in Doncaster.

'

On CAD, I want to learn it sufficiently to produce drawings good enough for making functional items in my own workshop, to my own designs.

TurboCAD's very meagre materials, including its extremely poor on-line "Manual", at least go straight into using that package.

Alibre: I felt that MEW exercise was drawing a scribing-block by rote, not understanding Alibre. When I realised my mistake, I deleted the lot. I did though, find how to improve the block's stability by enlarging and recessing its base!

I've subscribed to ME for years and started buying MEW partly for Alibre, but a pensioner now, will probably stop one or the other, or both, subscriptions at next renewal.

Fusion 360 looks forbiddingly difficult, and is even worse in assuming you already understand CAD concepts and want to make pretty pictures.

I bought two books from TEE Publishing on CAD basics, one by D.A.G. Brown, the other by Neill Hughes (whose publisher can't spell "metre"; but they can obviously only be very general. Brown's book is perhaps the better, despite its rather out-dated cover photo, by concentrating on orthographic engineering drawing; Hughes is really wedded to the pretty pictures approach.

-

Boiler Bri -

Ah, but with great respect you are illustrating the point I made, that all these CAD programmes are intended for use by professionals taught them professionally and fully.

Oh yes, I know ability to use CAD does not itself mean you can design or make anything. I saw examples at work of CAD detail-drawings meeting artificial "design review" standards of appearance, of items thereby very difficult or impossible to use!

Paul (TheCAD) Tracy once offered TurboCAD classes, but they were expensive. I don't what happened to him but he was the only agent for the only decent-quality CAD software available at a reasonable price to amateur engineers, and he used to advertise in ME and MEW. I bought my copy, on a CD, at a model-engineering exhibition.

Solidworks and AutoCAD are for trade and university buyers only, judging by their web-sites, and probably costlier than a fully-fitted Myford Super 7.

'

I'll stick with TurboCAD. I cannot draw isometric assemblies in TurboCAD of more than 2 or 3 simple, concentric elements, but luckily, unlike its rivals, it lets me make multi-part orthographic drawings directly.

Edited By JasonB on 04/06/2019 16:13:33

Hmmm. Interesting. Obviously how well you manage to learn CAD is extremely individual, as is the extent to which you wish or need to explore its darkest depths including Isometric models.

I have seen others similarly to Nicholas admit finding it hard to think of a three-dimensional object, orthographically. I don't find that, but perhaps from familiarity with engineering drawings and OS Maps.

I do find awkward, the unfolded-box model used to teach orthographic projection. To me, it flaps empty projection-planes about in space, so is too abstract. Instead, I pick up a simple, real object and by looking at each face squarely, see at once what goes on the plane behind (1st Angle) or in front (3rd Angle) of it. I.e. the object rather than projection plane is the more important.

'

Learning to draw manually does not require much tool-manipulating skill, so you can concentrate on the subject of the drawing, hence if it's original to you, its design. There certainly are difficult topics in manual draughting, such as interpenetrations, developments, loci and what my A-Level Technical Drawing course called "Lines In Space"; but these are all graphical plotting skills related directly to the subject, and use no more tools than any other part of the drawing.

On the other hand, Computer Aided Draughting (not "Designing" places a vast wall of complexity between rough pencil sketch and printed workshop drawing; even for simple orthographic drawings of straightforward items.

Isometric drawing manually is harder than orthographic, entailing a lot of plotting to make even simple circles let alone interpenetrations look right. In the workshop though, normally you need orthographic projections. Isometric drawings are good for assembly-drawings and helping you visualise a complicated item, but are not otherwise as important or useful as the orthographic images.

'

I found 2D CAD hard enough, and 3D too hard beyond a very basic level. I think the comparison with other subjects like languages interesting but erroneous, because we learn unrelated disciplines and their own topics in their own ways, and to personal limits on general and subject learning.

One limit is the level of abstraction - I understood (x, y, z) graphs in Maths at school because they related directly to familiar orthographic engineering-drawings and Ordnance Survey maps (I enjoyed walking as a hobby). Yet Matrices baffle me totally by being merely abstract sum-boxes with non-intuitive names and no link to anything.

I compare learning to filling buckets with water, on a beach; each sized for a particular discipline or topic. The seas of the world are inexhaustible, but once you have filled a bucket, any added water just overflows.

'

Isometric drawing in CAD lets you place a picture in the corner of the workshop drawing to help in visualising the part. The Hemingway Kit drawings use this. At professional level, it allows ready construction of assembly drawings and publicity pictures. For the amateur drawing for own use, these advantages are secondary at best, and outweighed by the sheer difficulty.

I bought TurboCAD hoping to learn it enough to help me draw the engine and transmission I need design for a miniature steam-wagon whose archive materials are merely a few old photos and some leading dimensions. I knew CAD has many advantages, such as copying and pasting similar elements, and that it would be a lot to learn; but I'd not bargained for it being so dificult.

Fusion360 deterred by its brashness, but more seriously, by being so confusing. My mistake with Alibre was that after some progress with TC, starting a very different package would be silly and costly. Also, both use isometric drawing first, so very roundabout indeed, and far harder. To its credit, TurboCAD allows 3D-first too, but gives you the choice.

That is NOT a matter of ability to visualise 3D items in 2D - that applies in manual draughting too.

It IS a matter of learning software unsupported by training materials. (Videos? Not all of us can learn from a video of an expert demonstrating his skill.)

CAD adds many concepts and traps non-existent in manual drawing. For example, tools not responding as they should, because they need certain, hidden conditions from previous stages. If you do not know these concepts and traps, you cannot learn CAD properly, but no-one tells you.

We are amateurs trying to use software for professionals, by publishers who expect it to be taught in full-time, professional courses. (I don't think SolidWorks and AutoCAD, extensive in industry, are even available for the amateur.) We can only buy the software then try to understand it without proper literature, tuition or prior understanding of CAD principles.

If I'd have stuck with MEW's Alibre offer I would now have a pretty picture of a scribing-block, but then what? I already have a real scribing-block. It would not help me draw my wagon engine!

Edited By JasonB on 04/06/2019 16:10:21

The facsimile manual (from Tony Griffiths) for my Harrison L5 tells you not to level the lathe, but give it and its cabinet a very slight tilt down to the chip-tray drain.

Bear in mind these lathes are designed to be on their own cabinets, a massive steel-plate fabrication with a planed top.

Logically, the only real advantage of having a machine-tool dead level by slide-ways or bed measurement is allowing work-piece setting by levels, and what really matters is that the machine is secured in a way that maintains its alignments and straightness without unfair strains.

A point indicated but not really raised almost at the start of this was the nature of the claims.

Those who claim to have "invented" perpetual motion that works on flat planets etc; clearly have a poor understanding of basic science. All the illustrious names, both engineers and scientists, quoted did either understand, or were seeking to understand properly, their particular fields.

Shady dealings and patents manipulating to steal intellectual property or personal credit is another matter - that is blatant dishonesty.

The example of bees that can't fly is different again, and turned out to have been based on people not asking the right questions because the paper was correct on the face of it. The notion was proposed by someone who'd tried to apply equations for fixed-wing flight, but it would be interesting to know what was genuinely asked by readers understanding the science but not spotting the weakness in the argument. Unfortunately, all the publicity focussed on the self-evidently mistaken notion, not why it was mistaken.

In a way it was the scientists' version of the fairy-photographs hoax: everyone looked at the evidence but failed to ask if the right evidence was used or had been gained in the right way. The method seemed inherently safe if the maths was right - bumblebees can't fly, but no-one's told the animals. No-one thought for a long time to question the choice of method and why the original researcher had taken his results as proven. An attitude less common now, but shown by the "computer error" excuse and over-reliance on said computer.

Ah, yes, I have just taken mine out of the tool-chest to examine it... No the PC's not in the workshop. It's in the lounge. The tools are in the hall.

Mine is the same as Adrian's, with its indicator needle and scale exposed at the end, not in a small window as on Nicholas' version.

'

Adrian: it's probably intended to be used as a height comparator on the surface-plate, so the scriber you've clamped yours to would act only as its support arm. Same as any DTI. Similarly for centring work on a lathe or rotary-table, from a turned surface on the work-piece.

'

I'd always thought my Unique's neat little tin-plate box, just the right size, was original to it; until I looked closely. It reads "By Appointment Tobacconists to the King" on the lid, and embossed in the bottom, is "Duty-Free H.M. Ships Only". By which I conclude, it was a snuff-tin, it being only of Unique DTI size. As for which King....

I must admit I've never used it, but it's there in case. In its case. By vicarious Royal Appointment at that.

Nothing in the workshop for now, as I've only just returned from hospital with a new left knee joint. I suppose at tome time they'd fitted white-metalled liners and a Stauffer grease lubricator...

My last but one pre-op foray was to the exhibition at Doncaster, but I don't think I will go there again. You'd expect a major racecourse to be easily accessible in outer suburbia if not countryside, not practically in the city centre or the rail-freight terminal. Rip-off food prices too, but blame the race-course managers, not the exhibition organisers, for what the equine world probably thinks pennies. Then via a stop in the Dales, to Kendal to collect my purchased Myford gearbox. The lady in the box on the dashboard sent me on a very strange point-to-point to the seller's home, though to be fair to her, she could not have known a particular road was closed for repairs.

So what to do while temporarily crocked and glad I'm not a race-nag....

I can still fight with TurboCAD. I thought basic 'Access' was hard!

Still, I had a basic-level geological article for my caving-club Journal to complete, and TurboCAD grudgingly allowed me to complete one 2D and two 3D diagrams for it. In time akin to knacker's-yard stagger rather than 13.375 Furlongs Handicap Chase.

They actually look-half reasonable but I was creating diagrammatic sections of hills; and Nature no more builds hills to ISO-approved metric milli-furlongs, than horses to integers of hands (1H = 101.6mm). So no worrying about more than visual alignment, and then by co-ordinates. Assembling 3D drawings elements by the "approved" course totally foxes me, and I've gone to ground on that one.

Nor did I need do what the CAD experts all like to show off 'cos they can: model the item isometrically then take off orthogonal projections from that. Apart from not finding any instructions for that anyway, my workshop drawings need to be orthographic, and I try to make them as accurate as possible (but know how to re-type "wrong" dimension values...). Why waste hours crashing into 3D CAD hurdles too high for me, when I want to make the 3D objects, not their pretty brochure pictures?

I did try Alibre, briefly, to see if it's easier than TC; but an unintended and unexpected succession gap between shop-bought and subscribed MEW issues didn't help me, then I saw the price for the real version. I've also sampled Fusion 360 (free for hobby and student editions presumably, like Alibre's trial edition, stripped of key functions) but went nowhere with that either. Also, both of these seem to insist on isometric-first. Bit like trying to learn to sing from The Ring Cycle libretto.

Ah well, I've still my A0, commercial-standard drawing-board...

Edited By JasonB on 04/06/2019 16:05:29

Thank you very much:

Michael - yes, I think there is enough steel in the spindle for that.

I would have either to use split bushes around sections reduced in diameter only in the journals, or reduce the full length and bush the pulley and back-gears, and modify the tail thread & collars. Err, I think split bushes!

Hopper - thank you for explaining the materials difference. While at it I would make a new thrust bearing pad for behind the nose, where the spindle flange has worn a recess some .03" deep.

I wonder if anyone can help with this:

E.W. Stringer 2.5" BGSC lathe.

The cast-iron headstock is in two parts dovetail-clamped to the plain bed.

The spindle appears to be mild-steel, or at least unhardened, a plain 3/4" diameter for most of its length apart from the thrust-flange and nose. It has a fine thread also 3/4" dia. on the outside end for the bearing collars, just inboard of a reduced section that holds the first change-wheel.

The bearing surfaces are simply directly spindle to headstock bores. No separate bearings of any kind. The castings are split one side only, for adjusting against their own elasticity by a cheese-headed screw.

The poor old thing is probably of mid-50s vintage and the spindle and bores have worn enough to make the chuck jump visibly. I would like to refurbish it, but there is precious little metal spare metal I can remove safely from the headstock, and undercutting the spindle for non-split bearings will truncate the back end thread and reduce the pulley section.

Options:

Bore the headstock and turn or grind the bearing areas of the spindle just enough to allow using bushes split to correspond with the headstock...

... Bushes of...?

- Oilites (commercial items in metric and inch sizes - but still need their walls thinning drastically, from the outside of course)

- Cast iron (is a c.i. bush of perhaps only 0.50" wall thickness feasible?

- Aluminium alloy (is that feasible even - it can be machined very thin but I don't know its bearing compatibility with mild-steel)

- Bronze (I understand it is not suitable for non-hardened mild-steel shafts, concentrating the wear on them.)

- Reinforced Nylon (bit easier than PTFE but still not the easiest material to machine, and likely to be more brake than bearing if the shaft warms up. 

- SRBF ('Tufnol' (Is used for bearings but I'm not sure of suitability here.)

- PTFE-lined steel (commercially available, metric-only, suitable size might not exist)

OR

Bore the headstock to minimum for rounding; make new spindle to suit. This involves the 1MT nose end. Spindle of...?

- Mild-steel?

- EN8 (probably tougher than needed but not necessarily less wear-resistant, though I expect it'll see me out!)

- Stainless-steel. (probably well over-spec for the demand).

+++

I envisage using the Harrison L5 with boring-table mounted, to line-bore the EW headstock (and come to that, tailstock) between centres, either still on their own bed or on a dovetailed adaptor.

Might be permissible to line-bore slightly below-centre, taking most of the iron from the stronger side; using as limit the faceplate clearance (I think about 1/16" above the bed).

The tailstock is thicker-walled, so a PTFE-lined or modified Oilite bushes could be feasible, with a small reduction in barrel diameter.

++++

The bed might like some attention too: machining-marks at the ends show it was simply fly-cut or face-milled. Whether that was original or by an overhaul I have no idea, but it is probably just short enough for the Myford VMC's bed and travel.

Cutting a right-hand thread away from the chuck entails running the lathe in reverse, so if using a screwed-mandrel lathe like the Myfords, beware of the chuck coming loose...

I concur with Howard Lewis' warning - whether studs, set-screws or bolts (I chose to suit the task), the fastening must not bear on the floor of the slot.

The commercially-available clamping sets sold by various model-engineering suppliers seem to be 3/8" BSW rather than M10, but anyway their nut threads are staked to prevent the studs passing through them.

For the delicate T-slots on my EW lathe's vertical slide and boring-table I made full-length T-nut strips, rather than separate nuts, with 1/4"BSW threads.

I take off the worst of the "teeth" with a file or angle-grinder before machining a stitch-drilled edge, to reduce the hammering effect on the poor machine and tool.

Cutting thin metal with an angle-grinder or a jig-saw is a bit quieter if you sandwich it between a couple of sheet of gash plywood or similar, with the under-sheet just clear of the cut, the upper a bit further back to be clear of the grinder. I did say "bit quieter"... These power-tools are noisy enough as they are!

I'd certainly take the above advice, but I've also noticed subtly convex ends on normal facing. Cross-slide worn / out of adjustment? That would affect parting, too.

Congratulations, Harry! The rallies and exhibitions beckon...

Me? Collected the car from being serviced and MoT'd, then continued fitting the DRO to the milling-machine. E-posted Machine-DRO to ask which was better - static magnetic strip or static sensor.

Alice Coles' very helpful reply was that most users go for the former (and it is easier and more logical for the long travel) but it does not matter from the electronics' point of view.

FMES - The MoD's ban may have been for technical reasons not connected with anything that would worry "the general public".

WD-40 is what the initials mean: "Water Dispersant (or Displacer?)". Despite the waffle on its cans, that is its best purpose, but you can also use it as an oil-dispersant for cleaning, .e.g miniature locos after running them, and as a cutting lubricant for aluminium. It is not very effective as a lubricant, nor as a penetrating-oil.

Plus-Gas is a long-established, well-tried penetrating oil. That is what is made for, nothing else.

It's better to buy materials like these in bulk tins rather than spray cans, but for covering areas you can use them in a salvaged, manual aerosol sprayer bought wrapped around a kitchen cleanser. (NB: The "aerosol" is the spray, not the spraying method!).

For point application, to minimise waste use a small paint-brush, wooden spill, the ink-tube from an exhausted ball-point pen (as a pipette), or similar. I've even used a twig.

Slightly digressing, the kitchen and bathroom also supplies potentially useful pumps, on liquid-soap bottles, that will draw off liquids in 5-litre tins whose spouts are designed to spread more of their contents over the surroundings as they pour into the container you use with the brush!

Unistrut is really an architectural / electrical-installation material, is folded or rolled from sheet as Michael says; and the applications I have seen rely on simple plain square nuts rather than T-nuts. Perfectly good for its intended purposes and could be used elsewhere if suitable, but it's not intended for precision-engineering or holding very heavy concentrated loads.

Regarding point-loading, it might be possible to overcome that by using long nut-strips, but this starts to get messy. (I have used this principle for the T-slots on my EW 2.5" lathe's boring-table and vertical slide, making not separate T-nuts but T-strips the lengths of the slots, to spread the load.)

Aluminium- alloy T-slotted channel is made, as Mike Poole says. To help search for possible suppliers, it is for such purposes as electronics cabinet assemblies and among what are sometimes called collectively, "transport sections" (for vehicle bodywork). However, Chris123 seems to need it to take quite heavy loads so these might not suit.

If all else fails, whatever this is for, the profile might have to be fabricated.

One wonders if a fresh look at the design is called for!

I feel as if I am criticised unduly, but I am not clear on what point.

I was not disputing the need to be able to set a vice or any other work-holding arrangement squarely - I simply suggested a way easier and quicker than tapping things with mallets. That might work for you people who obviously used machine-tools professionally for many years, but most of us on this site don't have the luxury of such intensive experience, because are amateurs who have to work alone, with the largely self-taught skills, the equipment and the time constraints, we have.

A lot of vices don't have accurate faces on any of the sides of the bases; but it may be possible to machine registers on some. The Abwood 6" vice I had for a time had a banjo-shaped, as-cast base, machined underneath of course but not even rectangular. ("Had" only because it was too large and bulky for my milling-machine.)

Actually the vice I was using does not lend itself to using one of its clamp-bolts as a pivot, by its design, if used across-bed.

Others suggest various dowel or tenon fittings - yes, all valid, and chosen to suit the design of the vice.

I have had to go to hospital to have a lump of metal removed form an eye... Not nice but luckily I had not done any lasting harm.

it's not only flying burrs or shards we've to consider, either; but there are times when we are handling chemicals would not want on our hands, let alone eyes.

Once, I dismantled an old NiFe (Nickel-Iron) mining-lamp case to replace the original three cells with a sealed lead-acid battery; for caving. The NiFe used alkaline electrolyte, and there were instances of people sustaining burns from this, usually when the filling/vent plugs on the cells leaked.

On my occasion I was sure the cells were all empty. Each cell was in a moulded-rubber case, making them a tight fit inside the stainless-steel outer battery case. One came away suddenly, causing me to stumble, but apparently without other problems.

Now, acid tells you it's there almost immediately, but alkali is insidious. It was not until that night I started to have something akin to "arc-eye", and realised I must have caught a tiny spray of remnant electrolyte, projected by the sudden movement as the cell came free.

Treatment was in Casualty, by running a thin stream of weak saline solution across the eye by cannula, for I think an hour - but with some discomfort for a while afterwards, not to mention the fear.

SO easy to hurt yourself; but these days there is even less excuse because PPE is so readily available from builders' stockists as well the engineering trade; and genuine health & safety advice and information is very easy to find.

In fact I'm only surprised we see very little PPE offered for sale on our exhibition trade-stands, or advertised in the model-engineering literature.

Edited By Nigel Graham 2 on 05/05/2019 01:06:24