Lathes & M/C tools

[bertiedog]

To clarify a bit, the steel to use is called in the trade in the UK Silver steel, it is a heat hardening steel for tools, and goes under many other names across the world, Gauge Plate, and Gauge Rod in the States, Blue Steel on the continent, also Drill Rod and Drill Blank.

 

Drill Blank in the UK means HSS

 

Most drills are made of it, unless HSS drills, most mills are HSS.

 

Silver Steel is not high speed steel, used for tool tips and forms, or carbon steel, which is case hardened to cut other steels. but hardened Silver Steel will cut anything that HSS does, until overheated.

 

HSS (high speed steel) comes in many forms and commercial.names.

 

Stephen

Edited July 25, 2016 by bertiedog

[Guest Isambarduk]

Is it a good idea to have to glue the ends together to make a belt, rather than start with a complete ring in the first place?

 

Yes, for the very reasons that bertiedog succinctly gave.  It is very easy to join and I have only ever (in 30 years) had one break ... and that was not at the join! 

 

To make the joins, I made a bespoke bit for my soldering iron that is essentially a copper rod with a piece of rectangular brass sheet let into the end, so that it looks like a strange sort of paddle.  I hold the soldering iron in the vice and, when it is hot, I touch each end of the belt either side of the hot paddle, slide them up and press them together. Voilà!

 

My late father, who was a very skilled engineer, was never one to allow any vagaries into a process and so, to avoid any chance of misalignment due to not bringing the two ends together precisely, he made a jig with two V-channels to support the ends whilst they were against a hot plate and whilst they were being pressed together.  When the exuded poly was removed you "could not see the join", as the saying goes.

 

David

[AndyID]

I've been know the melt the ends of polyurethane belting on our electric range (stove), but only when the domestic authorities absent

[Happy Hippo]

Isn't trepanning the name given to the mediaeval practice of drilling holes in the skull?

Still used today in brain surgery where a very fine and thin cutter is used to remove segments of the skull.

 

These are either replaced when the surgery is completed or removed and a new piece of stainless steel inserted as a cap.cutter.

 

The model engineering supplier Hemingway do offer a trepanning kit for sale!

[bertiedog]

The only reason I never used a jig to align the poly was I did about 2 a day in a photographic shop for years in the seventies, to fit projectors, you get good at it after several hundred.......and the years in high precision work with Schaublin, Pultra,and Lorch lathes, with full overhead drives as well, which required regular belt changes for special set-ups. The company had always used leather, and it took a bit of persuasion to get them to use the cheaper poly belting. The main thing was it was quiet, no high speed clacking from the joints. The poly does stretch with use, but it takes minutes to slit the joint and remove a bit and re-heat to join up again.

 

Stephen.

[bertiedog]

Rafifi, the infamous film scene where the cinema audience are shown exactly how to cut a hole in a safe without explosives. The treppaning cutter is rotated by ratchet lever, with a frame bolted to the back of the safe, and considerable pressure is applied to slowly cut the hardened steel with a carbide cutter. The authorities at the time, including the British Censor complained it gave away how to rob a safe!

 

 

Stephen.

[Horsetan]

^^

 

Now that is genuinely useful.....

[bertiedog]

You could of course save a lot of time these days by just using a diamond core drill, as in the Hatton garden raid in London!!

What was so effective in Rififi was the entire jewel robbery was shown in detail, and in almost total silence for 20 minutes. The only reason the censor passed it was that retribution by death due to greed caught up with all the gang! A classic of post war French cinema.

[Porcy Mane]

Avez-Vous un cuppa?

 

 

P

[bertiedog]

Mon Sewer,...trace of Eddie Gray there I think..Ohh!! and only people of a certain age will get that!...a great variety stage comedy favourite of days gone by, Monsewer Eddie Gray, complete with his dog, juggling and his Cockney French, long before Del Trotter mangled up his efforts at French. Worked with The Crazy Gang for many years.

 

 

Stephen

[Porcy Mane]

Isn't that the fella that introduced Tashspotting live?

[bertiedog]

[AndyID]

But didn't they have to drill and tap three holes first? If it had been me, the tap would have broken-off in the third hole.

[Quarryscapes]

Right then, right now i'm struggling with making some brake standards in the unimat, any advice on turning really thin and relatively long and fragile stuff such as this? 

 

I've created a handle by cutting a very short length of 1.5 OD 0.7 ID tube and slitting the end across (like a slothead screwdriver) into which is soldered the handle, made from 0.5mm wire. This was then supposed to be dropped onto the column, which I can create no problem - but the problem comes when I need to spin it round to create a spigot which I can then insert into the hole in the tender. Because it's tapered, I can't grip it in the chuck without damaging it, and if I hand it out of the chuck and go at it with a right hand tool it just pings off as there's too much unsupported. 

 

I'm now going to try doing the spigot first but using a steel spigot soldered into a hole in what will become the column, hoping the 1mm steel rod will be tough enough to hold the rest of the column. 

 

Failing that I'm going to slack off and just use the straight 1.5mm OD tube as a column and forget about tapering it. 

[AndyID]

Right then, right now i'm struggling with making some brake standards in the unimat, any advice on turning really thin and relatively long and fragile stuff such as this? 

 

I've created a handle by cutting a very short length of 1.5 OD 0.7 ID tube and slitting the end across (like a slothead screwdriver) into which is soldered the handle, made from 0.5mm wire. This was then supposed to be dropped onto the column, which I can create no problem - but the problem comes when I need to spin it round to create a spigot which I can then insert into the hole in the tender. Because it's tapered, I can't grip it in the chuck without damaging it, and if I hand it out of the chuck and go at it with a right hand tool it just pings off as there's too much unsupported. 

 

I'm now going to try doing the spigot first but using a steel spigot soldered into a hole in what will become the column, hoping the 1mm steel rod will be tough enough to hold the rest of the column. 

 

Failing that I'm going to slack off and just use the straight 1.5mm OD tube as a column and forget about tapering it. 

 

You might try drilling a hole for the sipigot first. Leave extra length on the blank that can be held in the chuck and drill all the way through it for the spigot hole.

 

Now put that end in the chuck, machine the brake standard and part-off the standard when complete. That should leave a hole in the bottom that will accept a mounting pin.

[Horsetan]

Mon Sewer,...trace of Eddie Gray there I think..Ohh!! and only people of a certain age will get that!...a great variety stage comedy favourite of days gone by, Monsewer Eddie Gray, complete with his dog, juggling and his Cockney French, long before Del Trotter mangled up his efforts at French. Worked with The Crazy Gang for many years.

 

Eddie Gray.jpg

 

Stephen

 

Looks like Alf Garnett.

[PatB]

Andy's idea is probably the most sensible, but you could try making a split collet by boring a piece of bar to the same taper as the column and slitting it with a hacksaw. It should then be possible to hold the column securely in the collet in the three jaw.

[bertiedog]

It is a problem with all items that are long a thin in a lathe, and a brake standard is on of them. Try to grip the blank with the thicker end towards the chuck, holding the bar material, and turn a small spigot stub on the end, and them use a cone centre on it, a centre with a cone hole not a point. Cone centres are made from bar, and can be gripped in the tail stock chuck with reasonable accuracy. Use oil in the cone.

 

This will allow the rest of the brake standard profile to be turned on one go. With such small items the speed must be at max, the tool razor sharp, and the cuts very light to minimise any chatter etc., that could bend the work. The stub spigot can be removed afterwards and the top split or drilled to take the handle.

 

This assumes the standard will be fitted into a plain hole and soldered. If the standard requires a tapped hole in the base, take the blank sawn off a bit long, and face, and drill, and tap, the hole in one end, take the blank out of the three jaw and turn around and grip the blank at the internally threaded end in the 3 jaw or collet chuck.

 

Then proceed as before, and you end up with the thread already done before the major turning, it is just a matter of planning.

 

Stephen

Edited July 29, 2016 by bertiedog

[halfwit]

Q.scapes - is your tapered brake standard flanged top and bottom? If so try holding the finished item gently in a 3 jaw or better still a collet gripping the job by the top flange and the part of the column that is of equal diameter (so that the job is held in two places). Then, rather than turn a spigot, drill a hole and insert a length of suitable sized rod. Another dodge would be to hold the job on its largest dia. with the outside of the jaws butting up to the bottom flange, with a modicum of care the job will run true enough. Carefull work with a drill won't put any undue pressure on the job, allowing a gentle grip, and of course there's no sideways pressure to worry about.

 

I have done this myself, both when drilling out tapered chimneys (using a home made split collet) and making a brake standard for a OO9 small quarry Hunslet.

[JeffP]

For those who are familiar with machine tools:

 

I've recently seen a post on Facebook about milling out tender frames using a milling machine and rotary table. I have the former, not the latter. I asked and the poster said she did not have use of any pantograph equipment.

 

So how difficult are we talking here?

[bertiedog]

All frames. loco and tender, can be cut out quickly on a milling machine and a rotary table, just a matter of planning a datum reference and milling the major edges first, then any cut outs for axle boxes etc., or drilling the holes for them, and items like frame spacers.

 

This can be done with or without a rotary table, which can be used to do angular cuts, or large radius curves. If you have a substantial rotary table then the work can be done in one go.

 

For frames I screw the pair firmly down on to hard oak wood, fit that into the machine vise, and mill with a slotting drill around the shape. The frames can be glued, or soldered, together to provide complete security. The slotting mill is useful as it can cut in a down action very cleanly saving switching to a drill to start a cut out without a path from the edge.

 

The datum reference is important, and you should plan the movements with careful written notes from the start, and keep checking at each stage that you are not off course.

 

Some curves may be short, and from defined points that may be best to saw, or file, out, the only method if you have no rotary table.

 

A pantograph milling machine is only used for mass production of items, using a larger master frame, although a complex frame could be made in wood at 3:1 and step down to a final one in brass.

 

For mass production of several frames at home, then simply stack more together for the milling, and use a longer milling cutter, and cut finer and slower to minimise risk of breakages.

 

Stephen

[jrg1]

All frames. loco and tender, can be cut out quickly on a milling machine and a rotary table, just a matter of planning a datum reference and milling the major edges first, then any cut outs for axle boxes etc., or drilling the holes for them, and items like frame spacers.

 

This can be done with or without a rotary table, which can be used to do angular cuts, or large radius curves. If you have a substantial rotary table then the work can be done in one go.

 

For frames I screw the pair firmly down on to hard oak wood, fit that into the machine vise, and mill with a slotting drill around the shape. The frames can be glued, or soldered, together to provide complete security. The slotting mill is useful as it can cut in a down action very cleanly saving switching to a drill to start a cut out without a path from the edge.

 

The datum reference is important, and you should plan the movements with careful written notes from the start, and keep checking at each stage that you are not off course.

 

Some curves may be short, and from defined points that may be best to saw, or file, out, the only method if you have no rotary table.

 

A pantograph milling machine is only used for mass production of items, using a larger master frame, although a complex frame could be made in wood at 3:1 and step down to a final one in brass.

 

For mass production of several frames at home, then simply stack more together for the milling, and use a longer milling cutter, and cut finer and slower to minimise risk of breakages.

 

Stephen

Pantograph masters can be made relatively easily in plasticard

[Vecchio]

Tool question: what is the thinnest practical parting-off tool?

Always best to grind one yourself. Made 0.8mm, but cutting depth only 3mm. If it breaks you make a new one. The only thing needed besides a wheel grinder are patience and water not to overheat the tool while grinding.

Vecchio

[jrg1]

Always best to grind one yourself. Made 0.8mm, but cutting depth only 3mm. If it breaks you make a new one. The only thing needed besides a wheel grinder are patience and water not to overheat the tool while grinding.

Vecchio

You could make one from an old hacksaw blade.  After grinding off the teeth and grinding the profile, clamp it with a steel strip either side (Screwed together) and secure int he toolpost.  Unclamp to regrind.

[bertiedog]

With hacksaw blades as thin parting tools always try to use only the HSS type, not carbon steel cheap blades, as they can be brittle.

 

Some makers use a compound type, Bi Metal, that has carbon mild steel as the main body and HSS bonded only to the edge to make the teeth, these are not much good for parting as the body is deliberately left soft, and can bend easily.

 

As far as I am aware junior size hacksaws are only made in carbon hard steel, and can shatter under stress, so the HSS blades must come from a 1/2inch or above size.

 

As no side clearance can be ground, they must be used with cooling lubricant when cutting steel, but can do brass etc dry.

 

The blade can have a holder made from steel bar, a saw slit in the end to take the blade and silver solder it into place, the heat will soften the steel, so heat again and quench in oil, then clean the blade and warm till blue to get back the hardness.

 

Stephen