clock key manufacture

Hi all,

I have recently (re)discovered my Dad's old Hornby clockwork train set - I last saw it about 40 years ago - and seems to need a little TLC. However before I can assess it properly, I need to wind the motor up tosee if it even runs. Unfortunately, there was no key in the box it was hiding in.

Now, I know the easy way out would be to just buy one - there is on on ebay for a few quid, now - but where is the fun in that ?!

I've started to think about how I could make one...some brass rod with some 'ears' soldered on and - the tricky part - with a square hole down the middle...

I think the original would have been made from a flat sheet (maybe a 1/16" thick) that was formed round a square mandel in some form of press...not a practical approach for me, given the tools I have to hand.

So how ise could I make the square hole in the key...?

If it weren't a blind hole, I'd probably drill a round hole and file it square, though I suspect that the hole in question is a but small for even that...?

How about if I were to make the squasre from 4 pieces of (small!) bar stock soldered together around a square former...?

What would be the best material to use for such a former? Specifically, something what would not stick to the solder?

I'm thinking Aluminium..? I guess it's be fine for soft soldering...? How about stainless steel?

Or alternatively...are there any other potential methods I could try?

2019's 1st challenge!!

Happy New Year!!

cheers

Paul

Piece of tube or rod with a hole drilled in it hammered down over a square shaft would do it, maybe hammer it to a rough square shape first and need to file a lead onto the shaft.

Edited By JasonB on 30/12/2018 20:31:31

Easiest way is use a square, bar mill a slot to form the key size plus a smidgin' then solder/weld another piece of flat onto the bar, centre in a 4 jaw and turn to a suitable O/D -- hard solder is best. Alternative form one from sheet metal, many of the original were thus.

John

An amusing exercise

Using Brass, and broaching the square hole would be a good start.

MichaelG.

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Edit: I've just had a browse ... Clickspring will show you how:

https://m.youtube.com/watch?v=J3ZGlpDa-0g

Edited By Michael Gilligan on 30/12/2018 20:37:58

Rotary broach is my vote too.

You could make the stem of the key like a thin walled tube and then solder in a short insert with square hole filed through it.

How you end up doing it will depend on what tools, materials, and skills that you have but to make a key that looks identical to the original would be challenging.

For a quick test of the clockwork motor you could use a standard radiator bleed valve key and reduce the size of its square bore with two thin strips of metal (one wider than the other) bent into 'U' shapes and pushed into the bore.

Ian P

Many years ago the shop where I worked had to make some special bolts with hex socket heads. We just pushed a hex punch into the pre-drilled recess. The material sheared out of the corners was driven to the bottom of the recess. The same could be done with a square punch.

.

.... a Toolmaker's Clamp is very convenient.

[ unless of course the winding square is down a hole ] 

MichaelG.

Edited By Michael Gilligan on 31/12/2018 06:39:47

The idea of forming press around a mandrel as in the OP should be do-able just in a bench vice albeit the time spent making a jig to keep the register is OTT for a one-off.

It'd be simpler to mill a square channel into some stock such that you have a tall flat-bottomed U shape, fit a mandrel then tap the sides over with a hammer and drift the mandrel out.

The laziest idea I can think of is to use round tube or a drilled rod, make up a square section plug, coat with release agent (perhaps just candle wax) to mould the centre when filled with epoxy steel.

pgk

As for the square section, I used the tang of a small round file - yes, the hole is left tapered, but that wasn't a problem.

.

Alternatively, it may have looked like this:,**LINK**

https://www.alamy.com/stock-photo-vintage-hornby-railways-winding-key-for-clockwork-model-trains-40235128.html

MichaelG.

Jasons idea of tube or rod with a hole drilled in it hammered down over a square shaft the same size as the clockwork motor.

The same idea works for bigger shafts with a square end. Recently made a crank handle for a mill with a 1/2" square shaft. Handle heated to red hot and hammered around a piece of square rod.

Paul.

Used to make box spanner’s that way out of conduit, opened up the end of a piece of 1 inch conduit with the ball end of the hammer and then closed it round a 3/4 inch conduit bush.

You could make any length spanner up to 12 foot that way.

I know you should not hammer two hammers together, but we got away with it, but it is not to be recommended.

When an extension adaptor was needed for the speedo cable on a friend's vintage scooter, I drilled a 1/8th hole, mounted a 1/8th HSS toolbit in the Tailstock The toolbit was plunged in about 0.010" using the Tailstock barrel, withdrawn, the chuck rotated a quarter turn and the tool plunged in again. This was repeated until the square hole was 1/2" deep.

The four jaw chuck made the 90 degree indexing easy.

It was slow, but produced the required result. Not that I am looking to make many more!

Howard

Edited By Howard Lewis on 31/12/2018 16:04:23