Idiots guide to brass

Hi folks,

Not only is it that time again but it's double as its bank holiday. So for those who don't know me don't worry you'll soon recover. For those who do. When you've stopped groaning. IM BACK...

Right down to business. I've got some basic brass tube 2mm OD and 0.3mm wall thickness. Now please remember apart from a lot of sharp knives and a junior hacksaw. I'm a wood top so have less than nothing in the line of engineering skills.

What I need to do is repeatedly, about 700 times, cut slices of said tube 0.5-1mm long. Now I know I can cut said tube with a sharp knife. So it's not too hard it's the accuracy I'm struggling with and I'm sure there is a safer way than a big swing with a meat cleaver. especially when I'm holding the tube. I still want to be able to count to ten without rummaging around in the sawdust.

So how can I cut this tube please?

In case your wondering what I'm up to now. I've given up on the distilling. It was all just hot air. And I'm now all at sea. I'm trying to make some pulley blocks. Enough to to rig the HMS Victory and about 8 other ships including three Cutty Sarks. And as the Victory requires around 700. Never mind the rest. I'd like a nice simple way of making them. Emphasis on SIMPLE please.

Hope you are all well since my last visit no lost limbs or nervous breakdowns. That's my job, to give them and have them...

 

Hi... Can't you borrow a small clock or watch makers lathe? That's the only way I would consider making that many. Or.... What about finding someone with a Boxford TCL CNC joby... That would certainly do the trick without losing your sanity!

John

First thought..I wonder if one could stiffen the inside with say an aluminium or plastic rod and then use a guillotine with a stop for the length. The guillotine would need a base board, metal strip edge and then a heavy blade (good kitchen knife or cleaver hinged at one end. If you can find one of those cleavers with a hole at the blade end for a hinging bolt... You then need two stops... one for length and one to stop the tube rolling away from the blade as you cut.

Second thought... If you're happy enough doing the cutting with a knife then make up a jig .. the rod resting between two closely spaced pairs of bearings.. it'll sit in the angle between a pair of bearings and be able to rotate.. and bridged across from the other pair gives you a gap to cut into. A raised block and stop at one end for the length and a guide for the knife. You should be able to build something robust enough out of timber for thin tube like this. Rolling the tube under the knife should give a clean straight cut??

Third thought.. hunt around for tiny brass spacers in that size and buy a bundle. It's the sort of thing that is used in small races to space the id of bearings so may be worth a google search.

Too late on the sanity side I'm glad. But my engineering contacts stop at the number zero so looney tunes here I come sorry already am :-P

If you are building a ship model why do you need to make brass washers? Wooden blocks work perfectly well.

Thanks for that. Not too sure about the first as it sounds way too safe . But the third is doable even if I used wooden dowel on marbles to create the bearings. And I'll definitely look into the third as its a route I haven't realised existed. That's why I'm here if in doubt ask the best. And I'm the biggest doubt...

Sounds worth a try thanks.

The only problem is inside the wooden blocks needs round wheels. And at this size wood just crumbles it's all about scale. While accuracy would be great I can't make wood molecules any smaller. So I've got to choose another product. Enter the next thing they used brass. And as its self lubricating if it's cheap enough because of the lead content which because of the structure of brass sits on the surface so giving it that smoot slimy feel. Wait that's an engineering fact. Oh my word your rubbing of on me quick pass me a lump of wood and perhaps it'll wear off...

Also last time I tried working with pignut vitea I spent more time sharpening the tools than working with them as its nearly like planning steel. And that's what was in the original blocks so no thanks.

But surely on a model the blocks don't actually need to work? They just need to look right.

I can't help but pop over to: http://modelshipworld.com and see how they do it over there.

The people that sell kitsets for wooden boats will also sell you little bags containing lots of little blocks, in different sizes too. They don't have actual sheaves in them but if this is a glass case model that should not matter.

John

Wolfram zu Mondfeld in his book "Historic Ship Models" shows how to make blocks from wood, boxwood is a good material. It doesn't crumble. But I have to confess that I didn't make the blocks in my model shown above, I bought them.

A possible solution might be to make a small guillotine. The blades would each have a 2mm hole in them and and be arranged to slide past each other. You could either have another hole in the plates as a pivot point or arrange for them to slide past each to be used in an arbor press. I have never tried this but it might work. You could add pgk's idea of putting plastic or aluminium rod through the tube while cutting it.

Les.

Edited By Les Jones 1 on 25/05/2015 09:11:02

Edited By jason udall on 25/05/2015 09:25:58

http://www.syrenshipmodelcompany.com/swiss-pear-rigging-blocks.php

Should have what you need.

Wooden jig, Dremel with circular saw.

> Wooden jig, Dremel with circular saw.

What the man says

I have a lovely little tube-cutting jig for use with a razor saw on test here from Expo, including a neat end-stop. I would recommend it except that you will get through a fair number of razor saw blades doing 700 and your hands will go numb.

Build a dremel into a temporary support so you can slide the tube past a cutting disk, you will get through cutting disks but may keep a vestige of your sanity.

Neil

They don't have to work but from rigging a 1/350 scale Cutty Sark. I realise that they still do the same job and as such all have to be adjusted until everything's just right. While this is possible with plastic or solid wood blocks there is a tendency for the lines to snag on the uneven surface. So creating tight spots which suddenly slip meaning all the other lines are out of whack. And the plastic blocks tend to snap at the becket causing even more headaches. So apart from the greater authenticity, it's a big help rigging the standing lines.