Member postings for martyn nutland

Delighted you liked the site.

Good question about chassis twist. My chassis are circa 1926. I've assumed that because there is no physical connection at all between the front and rear brakes what twist there is, aft of the mid-point of the car, deflects the cross-shaft without too much harm other than to the stability of the braking. Maybe that is why the brackets and the wrapped bush that support the shaft are so flimsy - to allow some movement.

I did nothing to the original cross-shaft because I didn't want to make an irreversible modification. The shaft is only a steel tube and I obtained a shorter one so it would fit between the chassis rails but not pass through the brackets. It's the steel spigots that are contained in the brackets on the new bronze bushes that now have a wall thickness of about 2.5 mm. The other end of the spigots is 'up the tube' by about 30 mm. How far is governed by the location of an anchor pin that is located on the right side of the shaft and passes through it. This is to hold the one end of the shaft return spring. The other end simply bears on the channel of the chassis cross-member. I secured the spigots in the tube with bolts. I wanted to use taper pins but didn't get that right! The other difference in my 'design' is that the brake actuating levers are now on the outer ends of the spigots, clamped there with a pinch bolt. Formerly, of course, they would have been attached by the same means to the outer ends of the cross-shaft.

All the best and thanks again for the kind comment about the site.

Martyn

Phil

I've taken hydraulic conversions back to what Austin intended myself, and I would be interested in what you think of my idea for the uncoupled vintage brakes. (Described on martynlnutland.com under the drop down 'Engineering'.

Of course, the fundamental point is that safety is all, and although you are correct when you say that a perfectly maintained and adjusted system on the later Austin Sevens can cope with modern traffic it depends rather heavily on skills many modern motorists do not have. I.e. a finally honed sense of anticipation and use of the gears in slowing (actually frowned upon these days by the experts) etc.

That said we do need to recognise that the Austin Seven braking system is notoriously poor. Some would say, virtually non-existent; but that is a bit of an exaggeration! Swerve don't stop, eh?

All the best.

Martyn

Hello OuBaillie

I can't claim intimate familiarity with ARQ Ruby brakes, but I have two vintage Austin Seven chassis and have thought long and hard about the vagaries, inadequacies and general bad design of the braking systems.

As you would know the early cars have an uncoupled layout, and to a greater extent than on your car, there is a problem concerning the rigidity of the cross-shaft. Also there is no effective way to lubricate it and, like you, I thought this latter point unsatisfactory.

To address both issues, I decided to try to strengthen the cross-shaft and support it in proper bronze bushes at each end, instead of the original wrapped 'tin-foil' types lining the flimsy brackets riveted to the underside of the chassis side-rails. If you are interested, you can read in detail on my website (martynlnutland.com 'engineering' in the drop-down menu) what I tried, but in a nutshell I made solid spigots to insert in each end of a new cross-shaft, cut journals on these and supported them in proper bronze bushes inserted in the chassis brackets. Where this may be relevant to your predicament, is it enabled me to fit grease nipples in the latter and regularly pump grease into the bushes.

While I've never owned a Ruby, I do have a chassis frame of that type. Looking at it this morning I could see a number of places where one might consider fitting grease nipples to advantage. I think that may kill several birds with one stone for you.

Clearly, and wisely, you are worried about muck and grit harming the 'works'. Yet, being a sensible chap, you won't be using an Austin Ruby other than minimally and on high days and holidays! Thus, if we adopt the traditional practice of pumping in grease until fresh appears 'in the gap', the old lubricant coming out will carry away the muck. (I passed some of my mis-spent youth doing this for the king pins, and indeed, brake mechanism, on my father's Austin Sixteen.)

And that said, I wouldn't worry too much about gaiters or other elaborate measures to protect the structure from dirt. Sometimes we have to accept that if an engineer of the calibre of Herbert Austin didn't think it necessary it wasn't, and, by the same token, if he did, we should play it by the book!

Good Luck.

Martyn

Hello John

I too am in the rather lonely position of machining in France - in Picardie.

I make stuff for my vintage Austin Seven projects.

I run a Chester Super B lathe bought locally, a Warco Economy mill and a Rexon drill press.

If you wanted to contact me and occasionally discuss issues I should be delighted.

My email is [email protected]

Good luck with the cross-slide.

Martyn

Manny and Dave

I don't really have the skill to go into the niceties to the last 0.0001" of what is good tooling and what is not.

But I bought a Vertex Posiloc collet system and I have absolutely no complaints about it in it's nice wooden box other than to say Posiloc is an awkward design to use compared with ER. The Vertex stuff seems well made and adequate for what I do which is make small parts for vintage cars for my own use.

On the strength of my experience with the collets, I bought a 4" Vertex milling vice. Again, absolutely no complaints. Nice finish, smooth operation, good grip etcetera. Could be a bit neater round the area of the scale on the revolving base. Can't detect any lift in the jaw that the experts bang on about being a bad fault, but there may be a thou or so I'm too insensitive to detect. Again, does what I need perfectly well. Worth the money.

I have no commercial interest in Vertex.

Hope this helps.

Martyn

Hello

I was really intrigued by Dave running his lathe at 3000 rpm. That boggles my mind. Mine can only reach 1260 and my milling machine just over 2000 and I've never been over 600 rpm on either, and at the higher range only with small work and/or a small tool on mild steel.

I still consider myself a relative beginner as I've only had the lathe about 10 years and the 'mill' about six, but am I being very timid? I also would rarely take a cut deeper than a fifth of a millimeter on steel. I don't however, have, for my purposes, a problem with finish using a sharp tool and, on the lathe, automatic feed - not 'mirror' but smooth and even.

By the way, Andy with the stalling Warco (another would be 2000 rpm runner!) was disappointed with his after sales service from this company. So was I with my mill. Great when I was buying it, but very disappointing when I thought I needed a new belt for the gearbox. 'Can't help - go to your belt shop (not so simple when you're in rural France) and anyway, we don't sell those machines anymore; they're obsolete'. Not what you want to hear, about what was then a three-year-old 'mill'.

Martyn

Ian

Very interesting and helpful.

As you probably know from my other posts most of the stuff I do is for the Austin Sevens I'm building. The biggest ER collet I have is 20mm which is the maximum recommended end mill capacity of my 'mill' and is as big as I would want to go given the inherent limitations of the machine. Fortunately the diameter of the things I make is almost always under 20mm (brake pivot posts for example) and they are usually quite short, rarely longer than about three or four inches so the collet chuck on the lathe suits. Above that though I would probably have to go to a scroll chuck.

So I take on board all the very helpful points you make. Thank you.

Martyn

Thanks for all that reassurance everyone.

The Chester has a 3MT taper in the headstock and I have on occasion successfully used small scroll chucks with that fitment or with the 2MT variant and a convertor.

I plan to use the lead screw from an ancient Furnival book-binder's guillotine I scrapped to make the draw bar as its dimensions seem about perfect and the result might be a bit more elegant than studding!

I gather though, it's important not to pull up the draw bar too tightly in these situations (only about a quarter turn) so as not to get the taper gripping too tightly as knocking the tool out will require much bashing which, of course, is not good for the headstock bearings.

Thanks again for all the advice.

Martyn

Simple question if I may.

I've been using, with vert satisfactory results, a collet chuck with ER32 collets to hold tools (endmills, drills etc) on my milling machine (Warco Economy.).

Could I use the same chuck (No 3 Morse Taper) fitted to the head stock spindle of my lathe (Chester Super B) with a draw-bar passing through the mandrel to hold material like bar up to the ER32 collet maximum diameter? Or do I need a special collet chuck for the lathe?

Best Wishes to everyone.

Martyn

So pleased this has been raised. I'm an avid watcher of these videos and many of the practices shown don't follow basic safety rules.

One of the best practitioners I find is Erik Vaaler, who while being a bit 'stiff' plays it by the book and Tubal Cain who is very personable seems safe most of the time.

I'm a professional writer and Hopper is right. Self-publishing means every tom-dick-and-harry is in print and while it has its upside the downer is it has devalued and degraded the craft. The same applies to video-making on machining and otherwise.

Martyn

Marcus

Some very helpful thoughts there also for which I'm grateful.

And I do have a factory-produced example to work from - to measure etc. And as you rightly say, it's not necessary to worry too much about and exact replica. It only needs to hold the fan spindle which is static. The blade is mounted on an eccentric (for adjusting the belt) on the end of the spindle and that's where the rotation takes place.

But the reason the big rebate is there is to circumnavigate an oiler on the base on which the pedestal sits. So that shape is necessary.

Thanks again.

Martyn

MartynThanks Jacob. Beautiful pump. Hope I can get a result half as good.

I wonder if someone could advise me on the best way to shape the complex radii on the part illustrated - this may not have worked, as I can't see any means of attaching the pix!

It’s another of my Austin Seven foolishnesses, this one being the fan pedestal. Replicas have just come on the market but I thought making one would be a challenging project and I’ve bought the aluminium now!

The trickiness is obvious and I really can’t afford concave (or is it ‘convex’, never sure whether you describe the shape of the cutter or the shape you want to make !) to form the spindle barrel. In any case, I don’t think those kind of cutters are really suitable for a vertical mill, lending themselves more to a horizontal machine.

I think a large endmill followed by a bit of judicious filing ought to make a fair rendition of the big rebate that rises vertically through the base and finishes beneath the barrel. But I think the way forward for most of this, once the basic shape is milled out, is riffler files. Would that be a sensible approach?

I did think it might be possible to cut the barrel radii on a rotary table. I.e. secure the work to the table and turn it against an endmill. The experts’ view on this would be helpful.

As always very many thanks in advance for any thoughts.

Martyn

Edited By martyn nutland on 27/07/2015 16:09:58

Edited By martyn nutland on 27/07/2015 16:10:35

Hello Again Brian

I've been thinking about your desire for a four jaw independent chuck and what we've been saying on the subject, especially apropos the difficulty of centring work that we beginners experience.

I don't want to speak out of turn here and not for a moment suggest bad practice but if your heart's set on a 'four independent' and the budget will run to it, this has helped me and might help you. (As I've said, I find trying to centre a four jaw independent a considerable pain, although I can now just about do it.)

Buy a self-centring tailstock chuck, the Jacob's variety (like a drill chuck) are cheapest and will take a workpiece diameter of up to about 16mm. Centre your stock in that, offer it up to the four jaw independent, and clamp on. Then test with your newly acquired dial indicator! Simples! I know, I know the shortcomings in both chucks, the tailstock etc etc can lead to discrepancies but for most day-to-day work is that a real problem?

If you want to go the 'extra mile' on cost you can now buy a self centring scroll chuck for the tail-stock (about £65 sterling) and use the same principle, but it will give you a much greater capacity for a workpiece than the Jacob's variety.

No doubt I will be shot down in flames on this one, but it might just help.

Happy Days.

Martyn

Thanks for the sums. I keep that formula to hand.

Martyn

Dear David Jupp

Sorry to be a real pain.

Could you possibly work this through with me line by line?

15 MM bronze bar...

Martyn

That's really brilliant everyone. Thank you very much. I should now be able to do this either by 'slightly trial and error' or if I get really clever using the maths so kindly explained.

I do hope my old maths mistress is looking down on us and duly impressed Nutland, once a thorn in her side, has bothered to concern himself with this!

Again thanks all.

Martyn

I think this very simple question might be a product of my mathematical inadequacies, but I’ve been trying to cut hexagons on a mill using a rotary table to turn the bar (bronze) through 60° six times. It’s been a frightful banjax of which I am deeply ashamed.

Two nasties occur. Firstly the flats are not equally wide and secondly they are not true axially. I don’t think there is a problem with the rotary table, the chuck I’m using to hold the bar, nor the mill itself. Moreover, I think I may not be calculating the tangents correctly to ascertain the depth of cut (with an endmill) necessary to create equal flats.

Thus I think a collet block set is the answer.

But what I don’t understand with collet blocks, is, again, how to cut to the correct depth. Obviously the dimensions of the blocks themselves don’t vary. So, for example, if one wished to cut a hexagon on a bar 15 mm in diameter you would start by putting the stock in the appropriate sized collet and clamping it in the block. But when you have the block clamped in the vice on the mill, how do you know how much to machine off for the first flat, before you turn the block for the next? Do you take, say, a millimetre, turn over, take another millimetre, turn again and so on; and keep going until you have a perfectly even (hopefully) ‘hex’?

Michael

You are so right about 'talking this one to death'. Or, don't let's tear the arse out of it!

Most of the posts have been so helpful and I can now definitely come up with a solution.

There's no need for elaborate special tools to get the darn thing out and I'm gratified that Austin Seven expert, Alan, does it exactly as I do. Hammer, drift, drill, chisel!

Thanks to everyone who has helped me here. Much appreciated.

Martyn