Suggestions for making cab spectacle surrounds

[Stringfingerling]

I've read Guy Williams descriptions of creating these with a lathe - I haven't got one though.  

My alternative plan is to turn a roughly cut out disc of brass mounted in a cutting disc mandrel in my drill on a drill stand, and dragged against a file ( yes, with eye protection!) - until it is truly circular and of the correct width.  I would then solder this disc to a larger piece of brass temporarily to hold the piece while it is drilled out to the correct internal diameter, using the existing hole from the cutting disc mandrel as a pilot hole.  Finally de- solder from the holding piece of brass and clean up.

Observations welcome or alternative methods.
 

[doilum]

Safer and easer to mark out both circles on the corner of a larger sheet. Drill out the centre slightly undersize and finish with a file. Then trim the outside with snips or scissors. Finish with the file or dremel.

[Stringfingerling]

Safer and easer to mark out both circles on the corner of a larger sheet. Drill out the centre slightly undersize and finish with a file. Then trim the outside with snips or scissors. Finish with the file or dremel.

Thanks for that, I expect you're right.  I'll try it your way  My methods are very homespun and untrained, though I usually get there in the end.

[Pebbles]

Solder two roughly cut pieces of say 10th brass to a piece of thicker brass of roughly the same width but about 80cm long - this will be used as a handle. Mark out and drill the hole then carve the outer shape gradually cutting into the handle until you are left with a sandwich of the two pieces of 10th and the supporting thicker piece. Should during the carving the sandwich starts to delaminate just apply the soldering iron. Finally force the sandwich onto a sharpened pencil and finish shaping; unsolder and clean up on fine wet and dry. Subsequently, the pencil can be used to locate the spectacle surrounds when soldering them in place. A similar procedure can be used to produce cab side windows. 

[Stringfingerling]

Solder two roughly cut pieces of say 10th brass to a piece of thicker brass of roughly the same width but about 80cm long - this will be used as a handle. Mark out and drill the hole then carve the outer shape gradually cutting into the handle until you are left with a sandwich of the two pieces of 10th and the supporting thicker piece. Should during the carving the sandwich starts to delaminate just apply the soldering iron. Finally force the sandwich onto a sharpened pencil and finish shaping; unsolder and clean up on fine wet and dry. Subsequently, the pencil can be used to locate the spectacle surrounds when soldering them in place. A similar procedure can be used to produce cab side windows. 

Thank you - that sounds good.  I suspect you mean 8 rather than 80cm for the length of the handle

[Stringfingerling]

Solder two roughly cut pieces of say 10th brass to a piece of thicker brass of roughly the same width but about 80cm long - this will be used as a handle. Mark out and drill the hole then carve the outer shape gradually cutting into the handle until you are left with a sandwich of the two pieces of 10th and the supporting thicker piece. Should during the carving the sandwich starts to delaminate just apply the soldering iron. Finally force the sandwich onto a sharpened pencil and finish shaping; unsolder and clean up on fine wet and dry. Subsequently, the pencil can be used to locate the spectacle surrounds when soldering them in place. A similar procedure can be used to produce cab side windows. 

The sharpened pencil sounds like a useful tip; the problem for me is often figuring out a way to hold the work piece when a vise (vice?) doesn't quite do the trick.

Edited March 8, 2018 by Stringfingerling

[Crantock]

There used to be a Mainly Trains etch.  Spectacle plates and ones with protective bars etc.  Another loss and something someone else should pick up.

[KalKat]

Brass wire wrapped on an arbour perhaps? After cutting, you could hit it with a hammer to flatten or file flat once soldered to the model.

 

 

Emma

[doilum]

Try and find some budget wood drills. These have a small centre point. Although not designed for metal, they work well enough on shim brass and are less likely to "grab" as they break through.

[Pebbles]

The sharpened pencil sounds like a useful tip; the problem for me is often figuring out a way to hold the work piece when a vise (vice?) doesn't quite do the trick.

Sorry about the length of the handle; but its main purpose is so that you don't really need a vice. When it comes to shaping any thine brass - and I see that brass shim has been mention - soldering it to a piece of thicker scrap brass largely overcomes the problem.

[Stringfingerling]

Brass wire wrapped on an arbour perhaps? After cutting, you could hit it with a hammer to flatten or file flat once soldered to the model.

 

 

Emma

Thanks for the suggestion;  I did do this a long time ago on another model, and it worked reasonably well, but it looked like what it was to me - filed down wire, and I'm trying to nudge my meagre metal working skills forwards a bit

[Stringfingerling]

Try and find some budget wood drills. These have a small centre point. Although not designed for metal, they work well enough on shim brass and are less likely to "grab" as they break through.

That's interesting, I've never tried that.  Generally I get round the "grabbing" problem by working my way up the drill sizes in very small steps.

[doilum]

Correct but that last drill always wants to have the last laugh. The wood bit scribes round the circumference.

[Retro_man]

I cut thin slivers off a brass tube using my 'lathe' - a 3/8" electric drill clamped in my bench vice.

 

I use a short piece of tubing projecting perhaps a 1/2" from the chuck and make a groove with a junior hack saw near the end. I then file the end of the tube so the groove is the thickness of the spectacle away from the end.

 

I then insert a drill shank into the tube and finish the cut with the saw. The drill shank prevents the spectacle flying off into oblivion and also prevents a burr on the inside which can be tough to remove.

 

If the tube is slightly too small, I slightly taper a drill shank and hammer it into the tube end to stretch it to the size I need before starting to cut.

 

This method works well with round spectacles but is useless for other shapes. Luckily I still have a couple of the Mainly Trains etches.

[Stringfingerling]

I cut thin slivers off a brass tube using my 'lathe' - a 3/8" electric drill clamped in my bench vice.

 

I use a short piece of tubing projecting perhaps a 1/2" from the chuck and make a groove with a junior hack saw near the end. I then file the end of the tube so the groove is the thickness of the spectacle away from the end.

 

I then insert a drill shank into the tube and finish the cut with the saw. The drill shank prevents the spectacle flying off into oblivion and also prevents a burr on the inside which can be tough to remove.

 

If the tube is slightly too small, I slightly taper a drill shank and hammer it into the tube end to stretch it to the size I need before starting to cut.

 

This method works well with round spectacles but is useless for other shapes. Luckily I still have a couple of the Mainly Trains etches.

[Stringfingerling]

Thanks - that sounds good to me. Another one to try if I've got some tube of the right size.

Correct but that last drill always wants to have the last laugh. The wood bit scribes round the circumference.

Ìll give it a go thanks

[micknich2003]

What is the exact size of your rings, and how many?

[Stringfingerling]

What is the exact size of your rings, and how many?

There are four of them; internal diameter fixed at 6.5mm, external diameter 8.3mm.   The external diameter is not so critical as the internal, as the holes for the spectacles have already been drilled in the cab sheets.

[ian@stenochs]

Hi

 

It is best to do the spectacles before erecting the cab This is a method which works.

 

For spectacle surrounds, of any shape, cut out or file two pieces of thin brass to the shape of the outside of the frame. Solder two pieces of brass together before shaping, 4 if it’s a tank loco cab and the back is the same as the front, and they will all be the same. Solder to the cab front in the correct place and drill through. Saw, file etc to give the inside shape. If the spectacle is round and you can find a bit of brass tube the correct diameter just cut a slice and solder in place. File to the correct thickness and open out the centre.

 

Ian.

 

[micknich2003]

There are four of them; internal diameter fixed at 6.5mm, external diameter 8.3mm.   The external diameter is not so critical as the internal, as the holes for the spectacles have already been drilled in the cab sheets.

 Here are your spectacle frames, I have done six, you can choose the best four, a little fettleing may be required.

 Message me your contact details and I will post them this afternoon.

[5050]

On 4mm scale industrials I have used top hat axle bushes suitably adapted (ie the 'rim' diameter reduced along with the length).

[Stringfingerling]

 Here are your spectacle frames, I have done six, you can choose the best four, a little fettleing may be required.

 Message me your contact details and I will post them this afternoon.

1 SPECTACLE 1.JPG

1 SPECTACLE 2.JPG

That is really kind of you - thank you very much indeed.  Details coming to you via PM.  Cheers, Rob

[Stringfingerling]

Hi

 

It is best to do the spectacles before erecting the cab This is a method which works.

 

For spectacle surrounds, of any shape, cut out or file two pieces of thin brass to the shape of the outside of the frame. Solder two pieces of brass together before shaping, 4 if it’s a tank loco cab and the back is the same as the front, and they will all be the same. Solder to the cab front in the correct place and drill through. Saw, file etc to give the inside shape. If the spectacle is round and you can find a bit of brass tube the correct diameter just cut a slice and solder in place. File to the correct thickness and open out the centre.

 

Ian.

 

3BB55BE9-2331-4DE4-BDAD-9B8A8BAA33AD.jpeg

That looks very good - thanks

[micknich2003]

How have you got on with the Specticle frames?

[polybear]

There used to be a Mainly Trains etch.  Spectacle plates and ones with protective bars etc.  Another loss and something someone else should pick up.

 

The major already has........