.

A plumb bob.

Make it as simple :-

Or as fancy as you like :-

Nick

Six diferent operations in an hour? They would be quick if there was to be any cutting to size involved! QCTP? Tools already set to centre height? Etc, etc? The simple plumb bob shows all but boring, so doable in an hour or so, for a novice. As long as they don't have to manually hacksaw a piece of hard steel, maybe…..

Ideally they should already have experience fitting/measuring and reading drawings before they try the machines, so hacksaws, files, scribes and punches, drills. You get the point. First lesson should be showing them how the lathe works,H&S and what exactly turning is, as well as the speed calculation and then you could try a basic step turning exercise.

I'm afraid you might have to explain to whoever is in charge that this is going to take more than a couple of hours. These kind of skills(turning,boring,facing,knurling,threading, tapers) are normally spread out over a number of projects rather than just one. 

Michael W

Edited By Michael Walters on 13/10/2016 08:06:29

It's a good point john, but there wouldn't be any drilling unless you wanted to make a scriber with replaceable tips, would be a better design i have to admit. You'd even have a bit of threading to do with the grub screw! 

It's probably just too much to take in one session for people who don't know what they are. Leave some decent tolerances on it then you wont make them feel like a complete failure. Although that seemed to be the point of my college course!

Michael W

Edited By Michael Walters on 13/10/2016 09:01:24

A simple thick washer?

I would set the topslide to 45 Deg at the start (to save time later) and use a 45 deg approach tool, then :-

1) Turn O.D.

2) Face

3) Form a small chamfer on the outside edge

(All the above done with the same tool. Hence the 45 Deg approach tool)

4) C.Drill & Drill

5) Bore

6) Generate rather than form a chamfer on the bore using topslide and boring tool

7) Part off (probably best with the rear toolpost if available)

Edited By Nick Hughes on 13/10/2016 10:18:29

I'm inclined to agree with George. Also 40 people ? All in one go ? I suspect not.

I think lots of people will be rather cautious the first time they are stood in front of a lathe and told to use it. Seeing some one doing a hands on demonstration with a bit of a chat might help with that and not consume too much of what sounds to be a rather short time. Throw in too much information and some will get a sort of glazed look and what is said will go in one ear and straight out of the other and don't I know it. Best kept casual and simple, sort of look how simple it is approach.

Boring seems to have stumped all suggestions. Maybe a brass or al egg cup ? It wont have a curved interior but could have a tapered internal bottom and eggs generally don't fit egg cups that well anyway.

I'm pretty sure that my first piece of lathe work was a centre punch. No boring and needs some simple heat treatment. There may be H&S worries if the end is polished up in a lathe for tempering but it could be done in a vice. Worth while too really as it wont be made of air hardening steel. Same with low diameter punches. I made a couple having got fed up with what can be bought. One's around 0.110 dia and used to knock out anything larger than that.

A small tap wrench is easy to make. 2 piece with tapered handles one of which screws in. The tap is held in a round hole that has had a V hand filed to one side. Ideally the screw in part needs a hardened insert in the end – say a short length of 3mm silver steel locktited in. In my case the centre part was hand filed flat on both sides but it could be turned or milled, 2 hrs though and it needs some precise turning and the use of taps and dies and a needle file.

A number of things I made in training followed me around on various sections. Part of the work done on one and more done on the next etc. In some cases that meant that they went away for hardening and were waiting for me when I finally got to grinding. Some started with hand work. One item that might suite and include milling is a certain style of tap wrench. I'll try and describe it.

Toolmakers clamps are opened and closed by holding the usually knurled screw heads and twirling the whole thing one way or the other to open or close it. The tap wrench is opened and closed coarsely exactly the same way. The "handles" are easy to make but need to be a decent fit where they pass through the side of the jaws to the one that has the screw thread in it. The jaws are just a square block split down the middle with V's added to grip the tap. The only complication I can think of is milling the V's so that they line up. My father and many others made these during their training and they stood many years of real toolroom use. The handles were a bit fancy, flanged at the end so that the diameter there was a touch less than the thickness of the jaws. Then reduced and came out again tapered to meet the knurled ends. 2 handles in 2 hrs – just about on I would have thought. Milling – easily.

John

–

There are several problems with what you're proposing. Firstly, and as others have said, 1-2 hours is not long enough to make anything useful.

Secondly you say "a Myford". Do you really mean just one lathe, or did you mean one lathe per person? If just the one lathe per group, that could mean 12 minutes per person actual lathe time (actually much less in practice).

Thirdly, given your numbers, that is 7 to 10 students per instructor – that is definitely too many if you're talking about complete novices who have never been in a workshop before, and especially so if they each have a lathe to themselves.

Fourthly, what are you actually trying to achieve, and what will these students do with this knowledge? You have to decide whether it's a safety training course or a practical lesson. If these students will be going on to do some proper machinery training then they should have more time in the future for a practical project. If it's safety training they don't need to make anything.

I would strongly recommend a re-think on the time allowed, and probably on the numbers (of both students and lathes). 1 to 2 days is a bit more realistic for just the basic safety training, double that if you actually want them to produce something.

Sorry to sound so negative, but it really annoys me when I see these sorts of courses proposed (and I saw lots in my past life) – there is no way you can teach a complete novice anything useful on machining in an hour or two and then expect him/her to have any real fundamental understanding of anything.

Edited By Steve Pavey on 13/10/2016 11:31:31

I can't remember how it long it took but in metalwork class at school we made a Toolmaker's clamp, involving:

– Marking out with ref' to a drawing.
– Cutting / Filing
– Drilling through and blind holes.
– Turning / threading / knurling / parting off.
– Heating to cherry red with oxy/acetylene and "blackedising"? in oil. I think the teacher did this part.

I still have the clamp somewhere in the shed.

Ed.

The clamps could also include milling again I think that is achievable and a useful end product. The screws would be easier to make than handles for a tap wrench. Mild steel should be fine too – free cutting so relatively easy to get a decent finish.

Like the tap wrench this can take care of the milling aspect as well. Every time I use some of my bought tap wrenches I think about making one.

There is another simple type as well. It starts with say 2 150mm lengths of square bar. Turn a short handle on the end of each. The remaining square parts overlap and are fastened with opposing socket screws suitably spaced apart. V's cut central to locate the tap. The knurl on the sockets screw is fine for tightening. I do use one of these for what might be called model engineering sizes apart from the small stuff. Definitely apprentice made. It came with one of my lathes. The screws are spaced some way apart – to gain a bit more leverage from them I suspect.

My Dad's rusted past redemption but would be using those if they could be resurrected. I used them as kid.

John

–

Looking at the video on the last type there is no need to centre that accurately or turn the handles that long – it just weakens them. He looks to centre drill too deep to me as well.

Dad;s type should have a square centre too – imho. Looks like he doesn't know about twirling to open and close them keeping the jaws square. Some don't know that can be done with tool makers clamps either,

Knurling is pointless too really. I find it often turns out too sharp. I was taught and do knurl in one go and don't worry too much about how square the knurl is to the work. In fact with a heavy knurl I'm pretty sure I have angled it slightly to cut it gradually.

Tut Tut oh dear, he doesn't reverse his taps to break the chips.

John

–

Edited By Ajohnw on 13/10/2016 13:24:15

Hi Joshua,

I think regardless of whether they are a child or a fully grown adult will be beside the point. They must be all taught to embrace the principles of metalworking in the same way, as you cannot assume one mans knowledge to be equal of the next. And as much respect i have for arts as a prior student myself, i would be lying if i told you this adequately prepared you for the basis of metalworking.

You cannot have self directed study without expecting a few knocks and chips on your tools, and maybe even a disaster if a workpiece or key is thrown out at high speed.

You've already said how disastrous it was taking on too many people, it could be the same result with even 40, you need classes of 12 people maximum.

I can't see how this setup would work without expecting them to be already competent in lathe work, as a kind of members commune, whilst i have admiration for your endeavor, it might be wise to scale down the size of this ambition to manageable numbers of people.

Michael W