best way to make holdown fixures

[alex 850]

i am a custom knife maker useing cnc to cut my parts out. i am haveing trouble makeing fixtures to cut out 6 to 12 parts out at a time what is the best way to hold these parts like the blades ,or handles,bolster etc. how do you set it up so when you want to cut the same parts out on another day with the same fixtre and get it on 0?

thanks alex

[SORCHEROR]

im not sure what your parts look like,im assuming you need to cut around the outside?
if you have some thru holes in the parts you could put them in first and use screws thru them to hold on the fixture,you need to make the fixture with a zero reference hole for pickup and at least one straight edge to indicate straight,you will need to know where all the parts are off that pickup hole and work from there,if you dont have holes than you need to have multiple straps and not cut all around the parts where the straps are,than move them and run another program to finish cut those areas or have an optional stop in the program,you can write one program for the first part and repeat it it for all the positions,hope this helps some what

[ImanCarrot]

Again, assuming you're cutting round a knife shape- I'd stick a couple of holes in the tang or handle, bolt this to a sacrificial steel plate or something making sure the plate goes back in the same position by using guide bars.

Machine round to outside but leave a bit near say the tip of the knife then clamp it using traditional methods or a big magnet and machine the tip bit that's holding it in place.

[ImanCarrot]

Incidentaly, you might consider Jeweling (or Engine Turning) your blades.. they look really nice... here's some examples of Jeweling, you only need a drill press, some wire brush tools and abrasive. I haven't got round to trying this yet, but it dun half look sweet.

http://www.customjewelshop.com/page2.html