Disc Cutter - Beginner's Question

[trampledown]

Hi,

I have been doing classes in silversmithing for about 3 months now. I've just received my Cooksons disc cutter - the one which cuts flat, concave and convex discs. There weren't any instructions with this and although I am getting to grips with the cutting the flat discs, I thought I'd be able to work out how to use the concave and convex cutters. It's not that obvious though and I found a Cooksons Youtube video for this but it only really shows the flat discs.

Also which is the best type of hammer to use with it?

Many thanks :~:

[Goldsmith]

A decent chasing hammer is a good addition to your tool kit.
The disc/dome cutters will only make a start to the shape you wish, any domed cut disc will need finishing on a doming block or a cone die, I believe that this is stated on the description of this product on the Cookson webpage as follows; " Please note: covex & concave punches produce a shallow cone. The disc will need to be domed on a doming block ".

[trampledown]

Thanks for your help :) I've used a doming block before but never to make cones - I guess this is what the cone die is for.

Can you tell me how the 7 concave and the 7 convex punches are actually used? They look like they are to be used together rather than separately. It is strange that the Cookson webpage describes them as 'convex and concave' punches as a hollow cone is both these things anyhow. It would be better surely to state that is cuts 7 diff sized flat discs and can begin the shape of a cone in 7 diff sizes?

I'm a little confused....

[mizgeorge]

I like a brass hammer for disc cutting - it's less likely to damage the punches.

I'm afraid I'm always suspicious of tools which claim to do more than one thing.

[trampledown]

Thanks George.

Can you recommend where to buy a brass hammer? I have searched on the Cookson site and they don't seem to be available here.

Gail

[ps_bond]

I've been using a Thor hammer with my disc cutter - copper one side, rawhide the other. As is my wont, I've got one that's complete overkill for this application, but it's handy in other areas.

[mizgeorge]

I got a 2lb brass hammer on ebay for under a tenner.

[Tabby66]

I'm with George, after trying a couple of different hammers, you cannot beat a 2lb brass hammer for this purpose!! (sorry, I'm no help with the use of the punches to make concave and convex shapes).

[trampledown]

Thanks all! Can't find a cheap brass hammer as yet but will keep hunting.

I await to see if someone who's used one of these can explain...

[ps_bond]

There's a set of instructions around - hopefully LittleGem will locate them, they're on one of my hard drives (somewhere) too...

[trampledown]

Literally just found them! On the knowledge base site on 'latest articles'. I will try this out later...

[ps_bond]

She found them first :)

[Dennis]

Literally just found them! On the knowledge base site on 'latest articles'. I will try this out later...

The members are in a sulk. Could they have the link please? Dennis.

[ps_bond]

http://portalgc.knowledgebase.net/display/2/kb/article.aspx?aid=315301

Added - sorry, it was worth a try, but the knowledgebase doesn't seem to allow direct linking after all... It worked when I checked it on my work PC.

[Dennis]

Intrestingly the instructions suggest that you can use the cone shaped punches to locate the first (smaller) hole and then using a larger punch, cut a washer.
If this works, it offers a remarkably inexpensive alternative to the Swanstrom, but of course much more primitive. Dennis.

[Dennis]

Engaging brain in the cold light of day, I note that no sizes are given, so that any washers made might not be large enough to turn into rings. Something beginners long to do, because of their dread of soldering. However shallow cone washers might be transferred to a collet plate to make tapered collets.

I have the collet plate and use it with tube, but it is quite challenging to get a tidy result. Not surprisingly I am unwilling to add to my tools graveyard by buying the disk cutter set to try this idea. Dennis.

[ps_bond]

I'm still getting a feel for bending a strip accurately for making a collet - it'll come with practice, but at the moment I still make a rough plot of how much curvature I need then bend it to shape.

You're correct that these won't do ring diameters - the largest punch being 5/8" means that you're probably not going to go much over 18mm successfully.