No32 Souvlaki & On the Subject of Necessity Being the Mother of Invention.....

Well, if anyone can suggest a better way of 'holding' scope tubes when baking on the suncorite in the oven I'm open to it! I get hell off her indoors because of the pong that lingers in the kitchen afterwards.......but some degree of transient odour is probably unavoidable.

Pretty well all of the tatty No32's that came from India have parts missing - some of them lots of parts. The Big Duke helped me with some sorely needed spares but is still in the process of getting his workshop built, so another fellow forummer got me some grat blocks for Mk3 scopes & some clicker plungers made. However, there's always something you never thought of. So, there comes a time when you just have to have a go yourself. I'm quite pleased, although I did have to make four attempts to get two usable clicker plunger retaining screws; the first worked out fine, the second fine, except I got a bit over enthusiastic with the parting off tool & so the screw lies as yet unfound somewhere in the dark recesses of my garage; the third one I got one of the dimensions wrong due to rushing after losing the second; & the fourth.........I also managed to get right.

No doubt I am making many mistakes, but I'm also learning a lot & thoroughly enjoying it.

I wound up getting a proper shop baking oven and can suspend parts with metal hooks. I use stainless steel blood hangers. They look good Rog. I've done a few scope tubes over the years but not too many.

Roger might be worth getting a mini oven to put in garage, then can setup to avoid the normal ear bashing from other half. Jerry had the same problem so bought something simple and similar to this to use in work shop Mini Oven | Portable Ovens | ALDI

Roger: Keep your eyes open at the local thrift store and pick up one of the larger toaster ovens.
They work well and once you get them set just mark the settings on the dial as the temperature markings are not that accurate.
Large toaster ovens are cheap as chips as you guys say and a large one is usually around 20 to 25 here at the local Value Village.
Same set up with rods and a frame and NOT SHMBO good baking pan.
Just take it to the garage or outside when baking.....

Thanks for the tips gents. I suppose it would definitely reduce the amount of earache I get if I get one of those ovens & use it in the garage! I'll look into whether they are available over this side of the pond as cheaply as in North America.

Brian, I use hooks for some parts too, but there isn't enough 'depth' in our oven to take a scope tube like that. Mind, I do suspend them, receivers, & various other parts in parkerising solution using hooks made from wire coat hangers cut into short lengths & the ends bent round. Works a treat!

Nice bit of lathe work Rog, yep small bits are right a pain, are you screw cutting the thread on the lathe ? or using a die nut ?

Hi Geoff,
I'm embarrassed to admit that I've never learnt how to screw cut on the lathe - I'm largely self taught & my skills are very limited. I use the chuck in the tail stock & open it enough to 'trap' the die in the die stock at 90 degrees to the job whilst bearing up against it. I then wind the three jaw chuck round by hand letting it 'draw' the die onto the job, thus cutting the thread. It's slow, but it usually works & ensures the thread is cut square. An old gunsmith showed me how to do it years ago in his garden shed workshop using his South Bend lathe that had come out of BSA Shirley at the death. I just use a little Myford ML7 in the garage.

Roger, dear o' deary me........ you are a total sucker for punishment. Those detent plunger housings are best made from a 6" length of brass bar, threaded all the way along. With me so far? Drill in, part off to AT THREADED LENGTH and same again, and again, and again until you have twenty or so..
What on earth do you want the step for the spring for? It serves no useful purpose....., the spring seats itself on the ledge, surrounding the plunger. It doesn't need an internal collar!!!!!
As for the round screwdriver slotted cap, then just machine bar to diameter and part off 50 or so circular tops. Soft solder round tops centrally to threaded inners. Simple I did one batch of 20 by leaving a small pip of material on the enner side of the top circular disc. And this little pip just sat into and closed off the open plunger hole.

As for the plungers.............

Thanks Peter. That's one of the reasons why I posted this thread - I'm always open to helpful suggestions, & someone, (you), has just told me a better way of making them! I'm with you & I'll do it that way in future. In fact, I know I'll need a few more of these components in the fullness of time, so I may run off ten or a dozen. It'll be much quicker & easier now you've suggested how.

As an aside, & I know Peter has spoken highly of them in the past, & I have always found them very good too, but I can't sing the praises of Tracy Tools, down in Dartmouth, too much. They always seem to have what you need, & when I ordered the 1/4" x 40 TPI Model Engineers die for making these screws on Friday afternoon at about 4.30pm I never dreamt a jiffy bag containing the die would land on my front door mat by 10am the next morning. Incredible service. I just don't know how they did it that quickly! If you need drills, taps, dies & so on I'd thoroughly recommend them. Their web site is easily found if you google their name.

Does anyone make a die for the double start elevation screw?

I don’t know of any off the shelf supplier, though others might. I have one, though it was purpose made by my late machinist Graham Smith.

(He made me a supply of lead screws & grat assemblies for Mk1 & 2 scopes & afterwards gave me the tap he'd made for the job).

I have to say that in the couple of years that I have repaired the sights I have only ever had to make a couple of lead screws and that's because they were missing! Worn lead screws are not a problem in Mk3's and L1A1's and are an easy fix in the Mk1's and 2's

Springs come by the foot and..........

Rog, re your threading technique, thats one way but to get it true use the same set up but use a die nut holder, put this up against the part to be threaded and use the tail stock fixed and wind in till its hard against the die nut holder......... as before wind/turn main chuck down, the die nut holder will or should stop itself against the lathe then its a matter of winding the tail stock in to keep the die holder square against the job, once mastered its easy, you can use this also to get a start on any threading etc to make sure its true and carry on as normal once the thread has started......

I have a baking oven made by Lauer. It's tall enough to suspend a barreled body using a hook. I prefer to install the barrel and paint it as a unit which makes for a very nice, even job. I admit that Suncorite is so tough that sometimes the body wrench won't even mar it if you're just changing out a barrel.

Taps and dies for the screws are around £280 for two sets IIRC, as they have to be made, I made enquiries some time back to complete some bits for Roger....... Oh and a two start tap you really need a jig to get it started or follow advice in previous thread use lathe etc but use a centre in the tail stock and wind in till it touches the centre of the tap.

If you have the eyes of a S**t house rat and patience of a saint and have a imperial cutting box on a lathe then its possible to make your own taps and dies,

The real Q is to ask what you need the taps and dies for? To replace missing - fair enough. To eliminate backlash - no need at all

Or, and no offence to anyone who is feels confident enough to tackle a rebuild on the hoof, without any formal instrument, mechanical or optical training, are we just imparting this info to aid the enthusiastic amateurs to xxxx their telescopes up.

Ask me about the now totally destroyed Mk3 drum that was 'repaired' because it was stiff. Well, it is now! Sorry but that's how it is in real life..................

Thanks Geoff. Tip much appreciated.

Quote:

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Originally Posted by Peter Laidler

The real Q is to ask what you need the taps and dies for? To replace missing - fair enough

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Just a few lathe tips and an answer to someones question Peter.......
Rog, watch this space as I'm just threading some 6mm and 8mm bar to make some crank case studs for my Matchless with 1/4" and 5/16" UNF thread...........if any anoraks are reading this the thread should be BSF or the old cycle thread, but you can still buy stainless steel nuts in UNF at a reasonable price, BSF/ Cycle thread nuts in stainless cost a small fortune.

Few pics for Rog,

As described in previous posts, this method will guarantee the nut runs square and not wobble all over the place, with practice a thread can be done in minutes, basically its a manual capstan lathe !!
You need to wind in the tail stock shaft whilst turning the chuck, always use some cutting paste etc.

https://www.milsurps.com/images/impo.../KWcrlAW-1.jpg
https://www.milsurps.com/images/impo.../MfXAmTZ-1.jpg

I've used the tool post holder to support the die stock and its free to move along
https://www.milsurps.com/images/impo.../2iIl7U0-1.jpg
https://www.milsurps.com/images/impo.../WLXZu6a-1.jpg
https://www.milsurps.com/images/impo.../M6H9iIT-1.jpg
https://www.milsurps.com/images/impo.../f3Q7eec-1.jpg

A set of the above studs sell for around £25 on ebay and there not even stainless...... although the tap and die set cost me £30 I took the plunge as I don't have many UNF or UNF taps and dies, my normal source is the car boot sales............. I've more Whitworth taps and dies you can you can shake a stick at.

Thanks for that Geoff. I've already made a few of the screws according to Peter's method, but I have enough brass to make about another half a dozen so I'm going to whilst I'm on a roll. I'll follow your suggestion for cutting the thread; what you advise is virtually what I was doing, except your method holds the die at right angles to the job better. Cheers.

Quote:

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Originally Posted by Roger Payne

Thanks for that Geoff. I've already made a few of the screws according to Peter's method, but I have enough brass to make about another half a dozen so I'm going to whilst I'm on a roll. I'll follow your suggestion for cutting the thread; what you advise is virtually what I was doing, except your method holds the die at right angles to the job better. Cheers.

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No problem Rog, your way is fine also but its getting the die square as you say and as its such a small thread etc no room for error, although this method does draw the die in the least resistance on small bits is crucial.

As an Apprentice in the training school we had to do it all by hand with a square etc, but it was mainly tapping, when we were in the college we were taught the easy way. One thing I do remember was two square metal blocks that were fastened together with several different methods called the "fastening assembly"

Of course you never got two square blocks to start with...... one side had to have material removed by chisel..... lots of lightening cuts had to me made then the waste chiseled away, what joy....

In the end you had one square about about 4'x4"x 1" as the base and a square approx 1/2 " that would fit diagonal on top of the big one.
All these sides had to be within a given tolerance and all square to each other, filled, scraped flat and then polished...... then marking out for the holes for fastening and dowels etc. Getting to this stage took some time and you were marked throughout the stages, to get this stage you didn't want to start again, so the tapping, reaming had to be spot on......... then the final hurdle was to drill the hole on one of the studs to allow for the split pin to go through when the castle head nut was torqued down.

What we never thought about at the time is each job you made it prepared you for the next, so all the taping and threading before did come in handy. I never got my fastening assembly back, it went into the Glass Display case outside the Training School managers office.............only works of art went to this case and it had been outside the office from when the training school was built, not much rotation on the items displayed, to have two pieces of work in there from the same apprentice was unheard of, until 1986......

Hi Geoff,
Many thanks for yours. All helpful suggestions are most welcome. It's at times like these that I wish I'd paid more attention to my metalwork teacher at school. Mind you, HAVING to do something as a schoolkid is a very effective deterrent to developing any interest in a subject! Looking into it because you want to makes a big difference. I found exactly the same with trying to learn a little French.....

While I was an apprentice, examples of our work weree usually presented to visiting dignitaries and other local visiting worthies. Alas. most of mine went into the 'also ran...' category. Like my set square, made during the last stages of our basic fitting part of the course. You were meant to take this square away with you to use thereafter instead of the crap Moore and Wright offerings. Alas, mine was the only 91 degree square. The class instructor wrote o my report to my parents words to the effect '.........a/t Laidler produced the only 91 degree square in the tutor group. He shoud mot be too down-hearted because when or if 91 degrees becomes the engineering norm, he will be ahead of the game.....'

Quote:

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Originally Posted by Peter Laidler

While I was an apprentice, examples of our work weree usually presented to visiting dignitaries and other local visiting worthies. Alas. most of mine went into the 'also ran...' category. Like my set square, made during the last stages of our basic fitting part of the course. You were meant to take this square away with you to use thereafter instead of the crap Moore and Wright offerings. Alas, mine was the only 91 degree square. The class instructor wrote o my report to my parents words to the effect '.........a/t Laidler produced the only 91 degree square in the tutor group. He shoud mot be too down-hearted because when or if 91 degrees becomes the engineering norm, he will be ahead of the game.....'

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Mmm that quote explains a lot.. :D