Member postings for Nigel Bennett

Chris

The Gibraltar Toolpost was dreamed up by Tom Walshaw (Tubal Cain) in ME quite a few years ago. It replaces the Myford top slide with a big cast iron toolholder, which removes the play inherent in a topslide so as to increase rigidity. I imagine a search in one of the on-line ME indexes would find it.

I described one in ME a year or two back to fit the Myford-Dickson toolholder in a slightly lower position than can be accommodated on the standard Myford topslide-mounted arrangement. It allows the use of 12mm tools, which the toolholders can hold, but you can't get them low enough on the topslide to use them!

Obviously turning short tapers is not practical with a Gibraltar-type toolpost.

Oh - one other thing that occurs to me; did you let the motor come to a complete standstill before reversing it? If you simply flick from forward to reverse, it probably won't, but just carry on in the same direction.

Hello David

The "reverse gear" is done electrically and involves the swapping over of some contacts within the switch unit. It's quite possible that the previous owner has not wired it up that way, or has been obliged to omit the reversing facility as some of the contacts have burned out. If it's the usual Dewhurst affair then that's a common failure. It may even be that the motor itself doesn't have the necessary wiring in place.

I would look out for a ML7 Manual. I think I've seen one in pdf format on the web somewhere, but they're readily available. You ought to have one for setting it up and for routine maintenance.

Reversing an ML7 is also a bit worrying on occasion as the chuck can unscrew, which can lead to a furrowed brow as you examine your broken workpiece and the dents in the lathe bed. It's very rare that you should need reverse anyway.

Look out on the usual auction sites for a copy of Ian Bradley's book on the Myford lathes - a lot of good stuff in there too.

Free Range eggs? They all seem to be priced...

I'm typing this one-handed. The other one contains four springs, Lee LC-035C-04-S. If you will email me at Nigel at PK dot co (and another dot) uk, with your address, I'll put 'em in an envelope for you!

Nigel

There are similar-sized machines to the Major but with a dovetail column. Warco do one (GH Major) and Chester do their Lux and Super Lux machines. Axminster and Amadeal probably do them as well. This gets round the loss of alignment problem quite well. (Unlike the VMC, they can be bench-mounted and so take up a little less room.)

These are all geared-head machines, so are perhaps a little noisier than belt-driven ones. I don't find my Lux too bad, but some set-ups need ear defenders if the job starts "ringing" - but that would be the same with a belt-driven machine.

Try to have a look at somebody's machine before you buy. Where are you?

The original question concerned the proximity of the tube holes to the flange. I had no bother in that respect with my Clayton boiler (I built it in 1988 or so and I wish I'd made it an inch taller!) Provided you drill the holes AFTER you flange the ends, you should have no trouble.

I made my safety valves a bit larger than the drawings, as I'd heard that they were on the limit regarding the accumulation test.

Thanks for that, Neil!

They make it look so easy, forging those rods. Amazing.

Edited By Neil Wyatt on 07/12/2015 08:17:48

Which JM Matthey flux is it? If it's Easyflo flux, I wouldn't use it on a boiler. It doesn't last long enough at temperatures for the length of time you need it to work for boilermaking. I've used Tenacity 5 with much better results.

If flux gets oxidised in a joint before the solder has run in, you've very little chance of recovering it as you can't get in to clean it for re-doing it later.

Easyflo is fine if you're doing non-ferrous fittings (I never use it on steel) when the heating time is quick.

The only disadvantage of Tenacity flux is that it's harder to get off after it's glazed, but the integrity of the joint is far more important than the expenditure of a bit of elbow grease.

Try JB cutting tools. They'll sell you one if they stock it.

Many years ago I bought a 5" Polish 4-jaw self-centring chuck, mounted it on a backplate on my S7 and then thought "Oh dear, it's a bit big." It just looked wrong. It wasn't weight so much that jarred, as the distance of the front end of the chuck to the headstock. Large bending moments seemed likely! By an amazing coincidence, they were about to buy an identical model at for use at work, so I persuaded them to buy a 4" one and we'd do a swop. Never regretted that choice.

Apart from trawling back through ME over the years for Lawrie Laurence's and others' articles, "Miniature Injectors Inside & Out" by DAG Brown is a mine of information on the subject. He also covers fault-finding and the design of water valves. Even if you don't intend making your own, it's probably worth a punt.

it's 435,4mm long at the top, 454,6 at the bottom (Angled backhead!), following Paul Tompkins' updated design (ME 4472, p17). 107,9mm OD.

Does that help?

You'll learn a lot about cutting angles if you buy a cheap 6" double-ended grinder and some HSS and grind your own tools!

Tipped carbide tooling has to be worked hard, and it needs a rigid machine to get the best results. Yours isn't in that category.

Many of the cheap sets of carbide tipped tools I've seen are not really suitable for taking fine cuts; feel the edges and they're surprisingly blunt. In these sets, the grade of carbide and the geometry are usually "general purpose".

However, lurking out there are many grades of carbide and carbide geometry to choose from. I've had a lot of success on a Myford Super 7 using DCGT11 tips; they're designed for aluminium and they're really sharp. They work well on steel, stainless, and bronze as well as aluminium. Downside is they're really brittle, so chipping them is all too easy. They do not work too well on brass as they have the wrong top rake and will often dig in with disastrous results. For peeling thick, smoking lumps off, (it's all relative!) I will usually start with a DCMT11 "standard" grade, and then finish with the DCGT11.

For 8mm tooling, DCGT07 size would be the one. DCMT07 is the "standard" grade with the "blunt" cutting edges for use on steel.

JB Cutting tools in the UK sell them; I've no idea about suppliers in Oz.

Oh dear. The OP wanted a simple system for learning to use CAD and it's been hijacked by professional 3D CAD users. (Yes, I'm one too; Pro/E and SW).

As others have mentioned, there are many cheap or free 2D systems about, but they all need a lot of work to enable a newbie user to be able to use. Yes, Draftsight is free, but whenever I've played with that, it's driven me round the bend. If I, as a professional CAD user, can't get on with it, what chance does a complete novice have?

So you choose a CAD system. Assuming that the necessary hair-tearing, screen-punching and vindictive abuse regarding the software designers' parents has subsided, some level of ability to use the system chosen should emerge. This is when the investment pays off, because even with an inexpensive 2D package, it's possible to lay out designs and check for clearances and functionality. Working out co-ordinates for drilling and machining becomes so much easier. You can add all sorts of extra dimensions on the drawing to assist you in manufacture - dimensioning from different datums if you need to. Add a DRO to your machine tool(s) and you can work in metric, Imperial, or barleycorns to suit.

In other words, you will need to invest a significant amount of time and effort on any CAD system before you see a decent return. But you can do it inside in the warm on a cold winter night when the shed is less than inviting!

All CAD packages (without exception) have one serious shortcoming. None of them have a "Just Do It" button. When somebody come up with that, and it works, they'll conquer the world.

We had a chap come to see us at work a while ago; he was selling Nord-Lock washers. He ran some tests with a rig he had brought, using locknuts, Nyloc, bent-beam, and they all came undone almost immediately. A plain nut with a pair of Nord-Lock washers underneath just sat there and grinned. Amazing. They use them on the pavement whacker jobbies - and if they can withstand that, then they're good for anything. I've specified them a fair bit with work. It's vital that you use pairs of washers the correct way round - they come glued together with a bit of Pritt or something just to hold them together. They can be re-used any number of times. Usual disclaimer. Google Nord-Lock for details.

Graphited yarn has been used for years with a great deal of success. You need a suitable cavity in which to fit the sealing medium, which is, as you surmise, compressed by tightening up the gland.

Depending on how the crosshead is attached to the piston rod, it may be possible to use O rings. Some have used conical-shaped PTFE seals whereby tightening the gland compresses the PTFE against the piston rod.

Whatever system of seals you use, the piston rod should be a very smooth finish, or you'll wear your seals out very quickly.

Have a look at some Stuart Turner or similar drawings; Model Engineer has shown the arrangement of seals for locos (eg Martin Evans, LBSC, etc), traction engines and stationary engines (eg Anthony Mount) over the years.

Like a lot of LBSC's designs, it isn't a particularly accurate model of the real thing. The frames and horns are not as the full-size 9Fs, which had the horns affixed to the outside face of the frames. I also found out (after I'd spent ages fitting steel tyres and fitting separate balance weights on mine) that the castings I had bought only had 13 spokes instead of 15.

Having said that, careful attention to the detail appearance (from photos) can give you a reasonable-looking locomotive which should run well - like Ken Ellwood's Times and Star which carried off a number of prizes in its time in efficiency competitions. If you want more accurate detail, you could always refer to the Les Warnett 5"G version, published in another magazine from about 1983.

Cheers, guys! It's obvious when it's explained! Like Richard, I assumed that the cars would use one side of the loop going up, and t'other one going down, as per normal railway practice. I had done an Internet search before submitting the question, but for some reason I never found the Wikepedia entry Martin Millener shows.

I was intrigued by the passing loop on the Cairn Gorm funicular railway. The passing loop has fixed points at each end - an advantage to have no moving parts in icy conditions. But how on earth do they work? If the wheels on the vehicles are flanged, then surely they'll derail, and if they're not flanged, they'll fall off! Anybody know?