Gallery, Projects and General > How do I??

How do "They" serrate cutlery knives ?

<< < (3/5) > >>

awemawson:
Bernardo,

I was sitting here daydreaming how I could fixture a knife held vertically in my CNC mill, with a 90 degree horizontal cutter held in the vertical spindle.

The slight curve on the profile could be accommodated in the program, stepping the spindle down 1 mm each iteration with appropriate X & Y moves.

Certainly need to make up a dummy to test it on before the live test !

AdeV:

--- Quote from: awemawson on November 08, 2018, 12:58:43 PM ---Certainly need to make up a dummy to test it on before the live test !

--- End quote ---

I should think you'd want a pretty damn good fixture too! I can just imagine a freshly-sharpened 6" knife firing out of the side of your mill at high velocity....

awemawson:
I have a box, secreted away somewhere, from when I had a horizontal mill, with a fair few odd angle cutters, hopefully something will be suitable.

I do however envision an angle plate  with a custom clamp towards the top allowing the vertical knife to rest on the mill table as a reference height, but just clamping the blade itself.

Also I'd reckon to run the spindle pretty slowly so hopefully not too many dramas  :clap:


Now where's my cache of spare time - haven't seen it in a while !

j1312v:
You are on the right path Andrew :thumbup:,

You just need to have a nice rigid setup :poke:, the right cutter  :dremel: and some spare time :scratch:

bEst

BeRNa12do

awemawson:
I found the box of horizontal milling cutters, and in it is a nice 90 degree cutter, but the tip radius it too large for this application. Then hunting around I found an internal threading bar with inserted tips that I think can be pressed into service. OK the gash will be 60 degrees not my estimated 90, but i'ts very shallow so I don't think that it will notice.

The bar can go in a collet held vertically and spun. I did today run a digital caliper over the curvature of the serrated bit. (Fortunately the bit of the blade opposite the serrations is a straight line to use as reference.) The width varies from 18 mm down to 9 mm at the point, with serrations every 1 mm. The Excel spread sheet that I put the data into will be the basis for a program to follow the curve cutting constant depth scallops. The blade where the serrations are is only 0.5 mm thick, and the cut is 1 mm long at 45 degrees so the cuts start deep and tail off to zero at the cutting edge.

Navigation

[0] Message Index

[#] Next page

[*] Previous page