Smithing advice please!

[Stanleythecat]

I am back on the shrink pot quest!

In short to make a bespoke tool to cut the v groove around the base of the cylinder into which pops the base of the pot. Having come up with an amazing invention 'the V scorp' late one night whilst I was waiting for the insomnia to subside (!!!) I found that flexicut make the very same tool! Basically it is just like a crook knife without a nice curve but an abrupt right angle.

I'm not paying for one of these as I quite like to make my own tools but I am struggling to get that nice crisp 90 degree (in fact what I need is more like 70-80 with a swan neck; a bit like a '7' in side profile) on the cutting edge; it is still only a tight curve. So how do i go about getting that crisp corner?

I picked up a cutting gauge cheap at the South West Woodfair and with this 'V scorp' I think it will be a winning combination!

I'm using spent chainsaw files as my metal supply.

Hope you can help.

Thanks

Leo

 

[Everything Mac]

You struggle with the crisp 90degree angle?

You could use a template for forming it. - such as a piece of angle iron already at 90 degrees.

I believe it is a good idea to upset the middle of the bend slightly as you stretch and thin the material quite a bit. Upsetting the middle helps prevent this.

All the best
Andy

 

[Stanleythecat]

You struggle with the crisp 90degree angle?

You could use a template for forming it. - such as a piece of angle iron already at 90 degrees.

I believe it is a good idea to upset the middle of the bend slightly as you stretch and thin the material quite a bit. Upsetting the middle helps prevent this.

All the best
Andy

Thanks Andy... what is 'upsetting'

I have been trying to form the corner on the edge of a small anvil and then by putting it in to the vice, bending over and then hammering... but its not crisp!

Leo

 

[Everything Mac]

Upsetting is where you heat a portion of the steel and hit the cold bits so that you end up with a fat section.

Several ways to do it of course.

http://www.youtube.com/watch?v=r986IuRiz0k

See how he has a fat bit at the end.

Best of luck
Andy

 

[Dave Budd]

is the crisp corner on the outside or the inside of the bend? If it's the outside then I suggest filing a V into a piece of scrap and forging the bar into it. If it's on the inside of the bend then there are several ways to make a sharp bend. One is to upset the middle, bend it as tight as you can and dress the bend into a corner using the extra mass that you have to prevent thinning. Another (and the easiest for this) would be to start with a large piece of stock thana small file, bend as tight as you can and grind the thing baco to the shape that you want.

There are going to be other ways I'm sure, but I'm not 100% sure of the overall shape you are after

 

[Stanleythecat]

is the crisp corner on the outside or the inside of the bend? If it's the outside then I suggest filing a V into a piece of scrap and forging the bar into it. If it's on the inside of the bend then there are several ways to make a sharp bend. One is to upset the middle, bend it as tight as you can and dress the bend into a corner using the extra mass that you have to prevent thinning. Another (and the easiest for this) would be to start with a large piece of stock thana small file, bend as tight as you can and grind the thing baco to the shape that you want.

There are going to be other ways I'm sure, but I'm not 100% sure of the overall shape you are after

Hi Dave

Thanks for the reply

Basically its a crook knife, bevel on the outside and shaped like a '7' so straighter lines and one strong angle as opposed to a nice curve. Like a 'v' parting chisel but held like a knife. I hope this makes sense?

Are you suggesting the 7 shape filed in to a piece of scrap and used as a template?

Leo

 

[Dave Budd]

ah. right with you.

if I made that and i wanted a sharp EXTERNAL corner, I would flatten the file to a little thicker than I want it to be, then forge it into a swage made by fiing the shape I want into a bit of scrap (try using a blunt chisel to push it into the groove). Then after its cooled just file or grind it to a true corner.

For a sharp INTERNAL corner, a way that should work is to flatten it (again still too thick), fold it over like a hair pin and forge the two sides togther (ie making a crease at the bend), forge the VERY TIP into a flat point (like a short obtuse V), open the thing out again and dress it over a corner or bar that is the right shape; this method would benefit from a little upsetting or leaving the bit at the tip thickened before forging the point.

for a blade with an external bevel the second method is better since the outside surface of the blade doesn't matter (the inside of the V or 7 needs the flat surface and sharp corner

 

[Stanleythecat]

ah. right with you.

if I made that and i wanted a sharp EXTERNAL corner, I would flatten the file to a little thicker than I want it to be, then forge it into a swage made by fiing the shape I want into a bit of scrap (try using a blunt chisel to push it into the groove). Then after its cooled just file or grind it to a true corner.

For a sharp INTERNAL corner, a way that should work is to flatten it (again still too thick), fold it over like a hair pin and forge the two sides togther (ie making a crease at the bend), forge the VERY TIP into a flat point (like a short obtuse V), open the thing out again and dress it over a corner or bar that is the right shape; this method would benefit from a little upsetting or leaving the bit at the tip thickened before forging the point.

for a blade with an external bevel the second method is better since the outside surface of the blade doesn't matter (the inside of the V or 7 needs the flat surface and sharp corner

Thanks Dave, excellent advice.

Can I ask for a little clarity on one point.

I'm not quite sure which would be the best edge for the bevel at the moment. A chainsaw chain is probably the best example of how the cutting edges might work (internal bevel) but a carver's V parting tool would work too (external). I've made an external (but not to my satisfaction) and will give it a try. But want to give the internal bevel a go now to compare the two; I also imagine sharpening with a chainsaw file might be an option...

When you say short obtuse V, do I understand you right in thinking the metal has been bent back on to itself and the two bits are now parallel, then on the outside of the fold you are in effect forging a slight bevel to take out the curvature of the fold?

Think I got it!!?

Leo

 

[nic.]

Leo posted this thread on another forum yesterday and I replied intially on there as to how I would tackle this, as I had a bit of time I knocked one up quickly.

Hopefully pictures paint a thousand words.

I made it really small as i thought it might be a good tool for carving initials with, trouble is it is so easy it seems a bit like cheating.

 

[Dave Budd]

ah I was thinking something bigger! Follow nic's pictures, much easier

 

[lannyman8]

oooooh, forged stuff....

 

[Whittler Kev]

Another (and the easiest for these) would be to start with a large piece of stock than a small file, bend as tight as you can and grind the thing back to the shape that you want.

There are going to be other ways I'm sure, but I'm not 100% sure of the overall shape you are after

Couldn't agree more.You struggle to get that 90 degree inner and outer without filing/grinding it - well I did when I made myself one
An outside cutting edge is easier to maintain as well

 

[Stanleythecat]

Couldn't agree more.You struggle to get that 90 degree inner and outer without filing/grinding it - well I did when I made myself one
An outside cutting edge is easier to maintain as well

What could I use as a replacement for a swage? I have a very simple kit and zero budget... I quite like the constraint though!

Leo

 

[Dave Budd]

piece of mild steel and file/grind/forge a groove in it. Not applicable for this tught corner, but I often use wood for short term swages too