Experiment cutting dies

[Shaun750]

But don't you have to angle the table so that the cut is chamfered?

Shhhh er gosh , maybe that's where I'm going wrong, I started this by just seeing pictures of the net and charged ahead. A while back i was about to buy the RT Blanking report,but it was so difficult to buy it from some jewellers guild,that I lost patience with them(send a check! or somehing!! send a check!!)..
I did thick if the negative half of the blank was tappered half way down the cutting edge,then it would help with getting what you just cut out.

[caroleallen]

I'm sure you could rig something up that was the right angle. I think I got mine from Suttons, or was it Walshs?

[Shaun750]

Cheers for mentioning that it has to be angled.It's only of a matter of a piece of wood on my 90 degree bench at the correct angle.
I can't work out what the angle does though? Even with a 90 degree cut there is a gap between the two parts.
Anyway I've got slightly distracted because of the metal I bought for the die. My brother has asked me to make him a hunting knife. A decent handmade knife can easily be £200.But that's without hand engraving or silver inlay,which I've said i will do. It's all metal work.Just with more sparks

[ps_bond]

I can't work out what the angle does though?

The angle means that the edges of the cutout line up top & bottom - which gives you a better shearing action. Depends how your geometry is - you need to know the width of the kerf & the thickness of your die material to calculate the angle. I'll run through the maths later on if you want/need, but I'll probably need to do some diagrams too.

As for the knife... What steel are you using, and is the inlay in the blade, the furniture or the handle?

[Shaun750]

The angle means that the edges of the cutout line up top & bottom - which gives you a better shearing action. Depends how your geometry is - you need to know the width of the kerf & the thickness of your die material to calculate the angle. I'll run through the maths later on if you want/need, but I'll probably need to do some diagrams too.

As for the knife... What steel are you using, and is the inlay in the blade, the furniture or the handle?

An pics about the die equations would be great Peter. I'd say I'm a visual person,some might say I'm lazy and a bit thick!

I was thinking in inlay both,but if it turns out nice,might quit while I'm ahead.I hope he actually uses it,if he ruins it,so what?
My Brother has spoken to someone about steel 440 c(stainless) he wants a mirror finish.
I've ordered some nice yew burr,which I might have a play with myself(could be a pen?)
I have made a rough knife(out of a half a pair of shears) just to get an idea,and started a dagger from an old chisel lying around. He bought me a belt grinder for the project.
I bought books on knife making over 25 years ago,it's all metal work to me.
Any info you can offer would be great.
Cheers Shaun

[ps_bond]

OK, how's this as a quick sketch:



You can see the top edge is in line with the bottom due to the angle of the cut.
If the thickness of the die metal is y, and the kerf width is x then the angle you need to use to get them to line up is atan(x/y) from vertical. A bit knackered right now, so a better diagram will have to wait! Also note that there is no tolerance in that calculation - your blade will wear & cut a progressively narrower kerf, there will be some variation in the angle you cut at... I'd probably knock off a few degrees and try. Or pay for the paper from the Goldsmiths' Hall

As for the knife - 440C is a good steel to use, but can be a bit fussy about HT. 25 years ago about the only stuff around was Loveless & Barney (can't remember when Jim Hrisoulas first went to print)... Might be worth getting some cheaper O1 to start with if you've got a new belt grinder to practice with?

[Shaun750]

OK, how's this as a quick sketch:



You can see the top edge is in line with the bottom due to the angle of the cut.
If the thickness of the die metal is y, and the kerf width is x then the angle you need to use to get them to line up is atan(x/y) from vertical. A bit knackered right now, so a better diagram will have to wait! Also note that there is no tolerance in that calculation - your blade will wear & cut a progressively narrower kerf, there will be some variation in the angle you cut at... I'd probably knock off a few degrees and try. Or pay for the paper from the Goldsmiths' Hall

As for the knife - 440C is a good steel to use, but can be a bit fussy about HT. 25 years ago about the only stuff around was Loveless & Barney (can't remember when Jim Hrisoulas first went to print)... Might be worth getting some cheaper O1 to start with if you've got a new belt grinder to practice with?

Cheers Peter,I can see what's needed now and why there has to be an angle. I'll have to bang that equation against my head for a bit until it sinks in.
I don't think I will ever buy the report unless i find it on amazon or something.Once I've been made cross there's no going back,I walk out of shops if I i don't get seved in a timely fashion!
I think I had a weird flashback with those authors you mentioned,I may have had that Loveless one.The one i do remeber one was called for ' For knife lovers only' For those who don't understand the appeal of knives,it sounds a bit werid. My books are long gone.Aint the internet marvelous! What and effort to learn something before it.

[caroleallen]

Somewhere I've got a chart that came with my RT blanking system. I'll see if I can dig it out tomorrow.

[Shaun750]

Cheers Carole.If you do come across it that would be great.
I was looking at a ball bearing draw slide today,it's for making my own version of the RT blanking system,I talked myself out of getting it.I've got to many distraction projects going on at the moment!!