Cutting a brass cylinder

vampireuk · Post by **vampireuk** » Wed Sep 16, 2009 3:01 pm

Afternoon all, I'm currently facing a bit of an issue. I have a brass cylinder, a now empty and fired casing that I'm converting into a money jar for a bit of something to do. I've marked up on a practice section from another casing. At the front of the casing I have marked a line at 45mm inwards and marked this point going 90 degrees to each side of the casing. At the top of each 90 point I intend to cut down diagonally through the brass to create a slope where I will braze another brass plate onto this angle and another brass plate along the top half of the case that is remaining flat. What are my options for making as clean a cut as possible without risking having the angle of the cut off and having to start filing down everywhere to make the cover plate fit snugly?

Post by **ultimatehandyman** » Wed Sep 16, 2009 5:39 pm

You could cut it flush on a metal cutting bandsaw.

Or you could use a hacksaw if you make something to guide the blade and stop it from wandering.

I'd probably cut just above the line though and file it afterwards as I have made quite a few bits using this teqhnique-

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vampireuk · Post by **vampireuk** » Wed Sep 16, 2009 5:44 pm

I forgot about the old above the line the file to fit, been a while since I have made anything.

I've done a trial run using a dremel which I believe could do the trick, but it would be a case of file to fit using that, along with embedding a shattered cutting disc in my safety glases.

Post by **ultimatehandyman** » Wed Sep 16, 2009 6:48 pm

If you cut it just above the cut line and then file it down it should be fairly easy as brass is pretty soft. When you get really close to the line you can draw file it, which should make it easier to get a dead flat line ready for the braising.

I had a friend who had some world war two shell and bullet cartridges that were made into hats and they were brilliant.

I'd love to see a pic of the finished item if possible

Hitch · Post by **Hitch** » Wed Sep 16, 2009 7:36 pm

A tricky one, easy with something like a bandsaw.

If it was me, id go with a 5" grinder and thin cutting disc. With care they can be very accurate.
If not, if the line is marked accuratley, hacksaw then file back.
Rotate it round, quarter of a turn at a time, cutting bit by bit. Possibly cutting through the sides first, then the top and lower sections.

The brazing will cover any slight miss alignment. I gather its going to be polished back afterwards?

Hitch · Post by **Hitch** » Wed Sep 16, 2009 7:52 pm

I forgot to add, easy way to check, mark it up, then offer it into a bowl of water at the required angle. The water will give you a flat palne across any shape. ;)

Other way is to set it up in a fixed position, then use a pen/scriber mounted on a block to mark the plane.

vampireuk · Post by **vampireuk** » Wed Sep 16, 2009 8:09 pm

I'll take a few pictures as I'm working away on it, I've already removed the primer, but I'll screw it back in so we can pretend it's starting right from the beginning.

And indeed it is going to be incredibly shiney!

big-all · Post by **big-all** » Wed Sep 16, 2009 8:25 pm

yep i use my 18v dewalt 115mm grinder with ultra thin blades for crafting steel ally brass ect

vampireuk · Post by **vampireuk** » Thu Sep 17, 2009 9:40 pm

I managed to borrow a bandsaw from a nearby workshop in exchange for another casing for them to turn into one.

Now another fun one, I'm looking at attaching a capbadge to the thing.

The badge itself is about an inch tall and is quite flat on the back, is there a way of making the item bend to fit the curve of the cylinder or is this one just wishful thinking on my part?

chris_h · Post by **chris_h** » Fri Sep 18, 2009 6:47 am

As for the cutting....could you not use a hand mitre saw with a metal cutting blade ????

Worked for me when I built my exhaust system

vampireuk · Post by **vampireuk** » Fri Sep 18, 2009 8:29 am

The cutting dilema has been solved.

vampireuk · Post by **vampireuk** » Tue Sep 22, 2009 6:24 pm

This was a test piece of material that gives an example of what I was cutting.

Here is the base along with the fuse assembly which had to be hammered out using a drift, hard work I can tell you and I pretty much ruined this assembly. Luckily I had another spare which is a lot tidier.

Here is the fuse removed from the casing, it's been cut down just above the thread as a plug for the money box.

Oh eck, bit blurred this one, shows the cut that was made on the bandsaw in comparison to the original shape.

Starting to shine up nicely!

It's all coming together, tommorow I'm going to visit somebody on my travels and see about getting the top brazed.

Post by **ultimatehandyman** » Tue Sep 22, 2009 8:59 pm

When I saw the second picture, I thought holy sh!t that has not been fired

It's looking good so far though

Hitch · Post by **Hitch** » Wed Sep 23, 2009 8:27 pm

As its polished, they will need to use a very close matching filler rod to the original....sometimes its hard to know what the original is.

I did some brass the other day, TIG welded, using small strips of the original material offcuts as filler, that ensures a perfect colour match.

Normally a slight missmatch is unnoticable while brightly polished, but when it starts to tarnish the joint shows up more.

vampireuk · Post by **vampireuk** » Fri Oct 16, 2009 1:05 pm

as promised, a couple more.

Just back in from engraving, some song lyrics my friend wished to be engraved on there for her.

I cleaned the thing up a little bit since it had been sat around for a couple of weeks with no polishing going on.

The brass lid metal glued in place, I was originally going for a braze but was advised with the thickness of the brass for the lid it would distort quite badly. In this one the lid is at a bit of an angle so I removed it and put the damn thing back on.

I forgot to get any pictures of doing the lid itself, I had originally gone with 3mm thick brass but cutting the material with the tools in my workshop was far too difficult and a decent shape would not have been possible. Luckily I had a roll of much thinner material used for shims which was easily cut, I used some snips for the first attempt, but it didn't look up to standard, especially after I knocked it with a hammer a couple of times to try and remove a kink, so the next was cut with a good old dremel which did the trick nicely. It's not going to win any awards but for what it is I'm quite content with it.

And of course, the finished article. :)