Member postings for martyn nutland

Thanks again. I can take it forward now using the formulae, reading list and practical advice.

Tim, don't go out in the snow. Not yet anyway.

Martyn

Again, many, many thanks for all the information and the trouble so many people have gone to to explain this.

I have come to the conclusion that gear cutters are not the way to go in this instance!

To Michael G, I would say, with the help of the forum and the internet I had 'worked a lot of it out for myself' but some of us are too daft to clinch the deal!

Thus, I'm still not clear as to which set of eight I might need for a particular task - an 0.5 module, 0.6 or what.

Putting the question brutally simply - which one for a gear train on a Showman's locomotive and which for the escapement on my half-hunter pocket watch. 0.8 for the traction engine, 0.5 or less for the watch I guess.

That said....I think the way to go on the Simms coupling is as suggested by 'old mart' - use a rotary table (in my case the dividing head) to measure the divisions and cut the teeth with a small ball mill and finish the angular tips with a file, Dremel or even a very small radiusing tool.

Can't thank you enough.

Best Martyn

Many thanks for all of that and for the encouragement.

As Lieutenant Columbo might say: 'There's still one thing bothering me'.

The tool supplier I use is RC Machines in Luxembourg who do indeed have eight piece cutter sets, just as we said. They are marked 20°, again as we said and then they have different number ranges to indicate the number of teeth each can cut. Understood.

Then there is a 'module' number. I now understand the 'module' to indicate the coarseness of the tooth; thus a low module should give a fine tooth, a high number a coarse one. However, the 'RC' cutters have numbers such as 0.5, 0.6, 0.8 etcetera.

So, following Jason B's most helpful advice of taking a Number 3 cutter from the eight piece set to achieve my Simms vernier gears, what module would I be looking for?

And, if I do other gears for different things in the future, do I need to keep buying additional eight piece sets of different modules (at 130-160 Euros a throw!)

Clarification would be, again, much appreciated.

Martyn

Hello Everyone

Seasons greetings and best wishes for peace and health from rural France.

I have treated myself to a dividing head (not a Christmas present!) This may be a bit ambitious on my part as I'm not sure my skill levels will enable me to master it. But I'd like to.

As far as I can determine from images on the internet, it's a clone of a Brown and Sharpe O Model Semi-Universal. It's probably Chinese judging by the incomprehensibly garbled manual, although it doesn't state it's parentage either on it or the box. That said, and I'm loathe to admit this, it seems rather beautifully made.

The prime purpose of buying it, is I wanted to make Simms vernier couplings for the magneto drive on my Austin Seven projects and this is where I would. appreciate some help. I'd like to do other work in the future.

As I understand it, one buys sets of gear cutters each one of which is suitable for a gear with a specific range of teeth. Say, for the sake of the argument, any number between 36 and 48. The next cutter would then take you from 49 teeth to 60 and so on.

But how do you establlsh the angle between the teeth? I think I'm talking about diametrical pitch (?). There seems to be a value in degrees on the cutters - for example 20°. Is that it?

So would the way forward, along the 'Simms road', be to count the teeth on the gear (19) measure the angle between them (?) and choose a cutter that includes 19 in its range and is of the appropriate angle?

I have a Machinery's Handbook and basic instruments such as grinding gauge, protractor, combination set, calipers etcetera.

As always very many thanks in advance for any comments and advice with renewed good wishes.

Martyn

Many thanks all - that's exactly what I wanted to know. There's no brazing or welding involved but it's useful to be reminded that there needs to be enough wall thickness to create the correct I/D but, very importantly, leave enough metal for the seating that takes the pad, shims and spring behind the ball connection on the drop arm and steering lever respectively.

Thank you again. Best. Martyn.

Hello Everyone

I want to make a steering side tube (drag link if you're American) for a vintage Austin Seven. Could someone tell me the grade of steel tube that would be safe for this purpose?

I know....look for an old one on the 'net'. But living permanently in France, as Brexit cometh, this is an increasingly unattractive option as I strive towards engineering self-sufficiency!

Thanks in advance and if it's not premature - seasons(?) greetings.

Martyn

Thanks for the additions. I can certainly work something out on this basis but accept 'attachments' are definitely 'out'.

Thanks again everybody.

Martyb

As always, many thanks for the observations and guidance. I think you have helped me avoid wasting much money.

I suspected the attachment offered by Chronos is only suitable for Bridgeports or Bridgeport clones. Even then I can't see how the dovetail support would fit onto the Bridgeports I have seen. The GTS item might go onto a Warco, although the taper is an issue. And there again, who would risk that weight of unsupported 'gubbins' hanging off the Warco spindle? Furthermore, as we all know, rigidity is 'all' in milling, and as has been pointed out, none of these set-ups, especially the GTS one, is going to be very rigid.

I don't think I can afford a horizontal mill or have sufficient work for one; neither do I really have the space.

However, I already have a three-slot rotary table that will configure vertically as well as horizontally, plus a dedicated three-jaw, self-centring chuck for it. If I bought another four slot rotary table (superior to the three) that came with indexing plates, I think I could contrive set-ups that would do everything I was hoping for with the horizontal 'attachment'. Yes?

Thanks again for all the valuable guidance.

Best Martyn

Hello

I'm considering investing(?!) in a horizontal milling attachment for my machine. This is a very expensive piece of kit in my terms and I wonder if experienced machinists would advise going ahead; or otherwise.

I'm running a Warco Economy. I fancy the horizontal device from Chronos (almost certainly a Vertex) because it has a support for the outer end of the arbor, although I can't, for the life of me, see from the photograph on their on-line catalogue how that would fit to the Warco.

Also, I'm looking at one (more expensive and definitely another Vertex) from Gate Tool Services that has no outer end support. That worries me although it seems it would fit my machine.

Important factor...I want to use the attachment just for more convenient use of my slit saws on some jobs and for some light gear shaping - for example bronze vernier couplings for magnetos.

Any views, experiences, however damning, would help me greatly;

Very many thanks in advance.

Martyn

Not a modeliste, but build vintage Austin Sevens from boxes of bits in what used to be Picardie, now Hauts de France. Lathe and mill a bit in a very modest sort of way to make small parts for them. Like others here find vintage engineering outfits hard to find but buy materials and tools from the most excellent company RC Machines in Luxembourg who will deal in English and have no silly automated credit card insistence.

I'm in Gueschart which no one's ever heard of, nor can find on the map. But it does exist and lies between Auxi-le-Chateau et Crecy-en-Ponthieu, or, if you prefer Abbeville et Hesdin!

4, Place de l'Eglise, 80150 GUESCHART (don't you just love succinct French addresses), website [email protected]

Best and many thanks for the opportunity to reveal this.

Martyn

Many thanks again for all the good advice.

I didn't know about shear tools which seem essential to the process.

Strangely enough, Tubal Cain has a whole video on making them and I'm now studying this.

Martyn

Many thanks all. HSS, fast, light, lubricant, stone. Got it.

M

Hello

I wonder if the experts could give me some advice on obtaining a high quality finish on a part.

I'm making track rod ends for a vintage Austin Seven. As many, many of you will know; on an Austin Seven a fork on the end of the track rod clenches a steel pin by means of the ubiquitous cotter pin, then the steering arm/track rod arm has a bronze bush to pivot on said pin.

I'm using EN16T at diameter +/- 9.5mm and for mechanical rather than purely cosmetic reasons I'd like to achieve as near to a glass-like finish as I can. Recently I used some steel described as 'polished' from my supplier here in continental Europe (the excellent RC Machines in Luxembourg) but found the tool tended to tear the surface and leave it rough how ever sharp the insert or light the cut. I don't want that to happen again.

I won't be tryng to harden the pin in any way - the mileage doesn't warrant it.

Any advice and many thanks in advance. Keep well.

Martyn

Like Philip, I've had trouble drilling bronze which I do when I make bushes. I have to confess that I have found that blunting the drill lips is of absolutely no help whatsoever! Maybe I do it wrong. As I understand it, what are termed the 'lips' are the parts of the tip that look like hooks and you are supposed to take the 'points' off said 'hooks'. I've bought and spoiled drills doing this and got no where.

That said, I find a brand new (or very sharp) unmolested drill will cut bronze as if it were cheese; no problem.

Just my experience.

Best Martyn

In the end I began by setting the flywheel vertically on the milling machine and, using a slitting saw (4" x 1" x 1/32), I undercut the teeth at the root in tangential increments. This is a laborious process as there are 80 teeth and the saw would only span 5 or 6 teeth at a time.

Edited By JasonB on 09/02/2020 16:23:09

Many thanks all. I will have a go and report back.

The question as to 'why bother' is sensible. It's just that, although it will be out of sight, it looks and is a mess and offends the eye.

Back soon

Again, very many thanks for all the advice and practical guidance. This accords with everything I have read and studied on the subject of enlarging/profiling ports and I will be printing this off and keeping it close as I work. Congratulations to everyone who has already made such a splendid job of the procedure and, above all, thank you for sharing the expertise with me.

Bonne Année

Martyn

Many thanks everyone.

Inlet.

Dremel

Especial thanks to Grindstone Cowboy. You seem to understand exactly what I want.

By the way Brian...I'm not into 'messing' with pre-War components. That is normally anethema to me. I'm just using conventional (pre-War if you like) engineering methods to try to improve an extremely poor aspiration system as thousands of Austin Seven Special builders have done since pre-War days!

Thanks again everyone. Bonne année from warm and sunny Paris.

Martyn