scribing centerlines

It depends on what stock you are starting with. If I'm using flat bar stock, I measure center front and back with a rule and scribe a line. If It's something I forged I take the centerline of the tang and carry it forward. If it doesn't have a straight tang or the blade is so irregular I can't measure it, I "eyeball it".
 
Centerline ? what is that I didn't know that I was supposed to put a centerline on the blade before I started grinding..:D :D :D
I do all mine by eye.But I do have a marking scribe for my sheaths and things like that.The scribe is just a flat piece of brass with a hole in one end that I inserted a rod into that has a sharpened end of a drill bit soldered in at a 90 degre angle to the flat bottom,then I threaded a hole in the end that lets me tighten a bolt against the rod to hold it in place.This will work for marking centerlines on Blades also.
Bruce
 
I just use an old engine valve [with the edge sharpened] in the drill press, with the table adjusted for near center. A quick trip around, turn it over and finish the other side.

Saw this in a video, not sure which one. Quick and easy.

Dave
 
I do it by eye now also,but years ago I made a scribe using 3/8"x3/4 "x2" aluminum,2 pcs of 1/8" brass rod 1" long and a 1/8" broken drill bit.You can use a new one.Grind a point on the shank end of the drill bit not getting it hot.Drill aluminum and tap holes for the holder screws.I used 6-32 tap.When using just turn until brass touches blade,then drag down spine,Hope this helps.Dave

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Sheffield Knifemakers Supply sells a great little edge scribe with a carbide point so the line is still visible after heat treating. Honestly, I couldn't make knives without it.
 
Wow. Thanks for all the suggestions. I think that I am better off with buying a tool given my extremely limited shop experience.;)
WinDancer,
Allen Blade had the engine valve trick in his videos. Looks like it works easy for him. Of course he has a way of making every aspect of knifemaking look easy.:)
 
Here's an easy way to try prior to buying anything..

Coat the edge of your steel in permanent black marker.

Lay the steel on a flat smooth surface and use a drill bit the same size as the thickness of your stock to scribe the line, the point of the drill bit should be exactly the centerline of your steel.

Just lay the bit down perpendicular to the steel and pull it along the edge of the steel.
 
I do it like CPirtle does and use a permanent marker on the edge, and use drill bits. Except I usually use a drill bit 1/64" smaller than the thickness of the blade, and then I scribe, then I flip it over and scribe again, so there are two lines very close together.
 
I use my calipers and resently ran across a set with carbide tips that I plan on getting.
 
Hi all I been using a fly-cutter in the mill lowered down over the large flat on the mill-vise with a custom ground carbide lathe tool bit turned upside down. Then set the height and just drag the blades across the top of the vise. I bet this trick would work in a drill press also. Take care GenO
 
What do you do if you forge your blades and they have a taper in them? I use the by eye method but was wondering what the rest of you do.
 
Thats what I do Bill B ????, after I forge, I clean up my shapes with the grinder, cut my plunge cuts in with a file to the center of the cutting edge(leaving it a little fat) then grind in my bevels, on a flat grind it is real simple and comes out even. Use the spine for your gauge when grinding in the depth, if you don't over grind and just grind to the spine from plunge to tip she'll be straight and even. If its off a little when finished just straighten it up to the eye. Its not hard, just keep things simple and keep checking your depth from time to time along the cutting edge.

MERRY CHRISTMAS ;)

Bill ????
 
Howdy There...!
I do stck removal so I am using a basic similar thick material all the time. I took and old lathe cutting tool that I bought at the local flea market and ground it to th shape and height that I wanted for my blade thickness. I have one side ground for 1/8" stock and the other side ground for 3/16" stock, color the steel with marking dye lay it on a flat surface and run the sharp edge of the tool along the blank. Works great...and cheap..!

"Possum" :cool:
 
I do what Possum does only I use a center line and also 2 lines (one on each side of center).020 apart (.040 total). I grind to these outer lines I feel it's a little more accurate. I also feel it cuts down on the chance of blades warping...... I know I know I'm a real PIA sometimes.

Eric :eek: :eek: :rolleyes:
 
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