Center scribe blade edge...

J

jakeotter

Joined
Aug 29, 2014
Messages
32
Hi sorry for the idiot question....
I've searched online and on this forum, can't seem to find a good way to scribe my center line on a blade before grinding the bevels. I typically just use drill bits and kind of 'guesstimate' but there's got to be a better way. I don't care if I have to buy a tool or make one, I'd just like to have a simple and reliable way to do it every time. What does everyone else do ?
 
Height gauge and a surface plate/granite block. I'm interested to hear what others have to say. I've been using a tool I made, but it didn't work as well as I hoped it would. Drill bits aren't working well anymore either.
 
I use my dial calipers. width of blade divided by 2 plus .010"... for a .020" edge. drag one of the arms along the edge while the other scribes the line. flip over and repeat. there is a scribe gauge you can buy too.
 
I use the one from USA Knifemakers - works great. I doubt you could make one for $43 if you pay yourself minimum wage.

Tim
 
samuraistuart said:
I use my dial calipers. width of blade divided by 2 plus .010"... for a .020" edge. drag one of the arms along the edge while the other scribes the line. flip over and repeat. there is a scribe gauge you can buy too.
Click to expand...

Bingo. I've been using $15 Harbor Freight digital calipers for years reloading precision ammo and scribing. I also have a set of mitutoyo dial calipers but the digital ones are easier and just as accurate in my experience.
 
Jake, You may want to take a look at the knifemaker's for sale forum and search for "precision height gauge" . I have been selling Mike Peterson's precision height gauge for him as a favor. If you like fine tools and want to scribe perfect lines for your blades then you might be interested. They are custom made prototypes and limited in number. Mike Peterson is a retired master machinist who has made a few parts for my tool rests. Larry Lehman

32dCSl0l.jpg
 
I love it when everyone suggests a new fancy tool to do the job a simpler tool does....and you already have that simpler tool.

Take a drill bit that is just a tad smaller than the thickness of your blade stock ( technically, .020" smaller is perfect, but any slightly smaller bit works). Lay it down on a smooth and flat surface. A countertop or workbench top is fine, but if you have a surface plate, use it. Hold the drill bit in place ( or clamp it) and pull the blade blank along the bit's point. Flip the blade over and run down the bit's point again. You will have two parallel lines close together. Grind/file the bevels to these two lines.
 
bladsmth said:
Take a drill bit that is just a tad smaller than the thickness of your blade stock ( technically, .020" smaller is perfect, but any slightly smaller bit works). Lay it down on a smooth and flat surface. A countertop or workbench top is fine, but if you have a surface plate, use it. Hold the drill bit in place ( or clamp it) and pull the blade blank along the bit's point. Flip the blade over and run down the bit's point again. You will have two parallel lines close together. Grind/file the bevels to these two lines.
Click to expand...

This is what I do 90% of the time. Simple, quick, effective. I have 12x12 granite tile I use for the flat surface.
 
I tried making scribes out of scrap pieces of knife steel with varying degrees of success. Then I ended up with a method very close to what Stacy describes. I get a very long drill bit from Home Depot or Lowes for drilling out my hidden tang handle holes. The bit is too long for that job so I measure what I need and cut off the rest. The excess goes over to the belt sander where I clamp a 1-2-3 block to the tool rest set at 90˚ to the belt. The block or anything else similar you have handy gets clamped as a guide to the tool rest at an angle. Feed your cut off drill rod into the belt along your clamped guide while turning the drill rod so you end up with a nice conical point. It doesn't need to be a long thin point, just conical. I do this with drills matching the steel stock I use - 1/8", 3/16", 1/4". Then holding your profiled blade blank down on a flat surface like a granite surface plate, lay your drill rod on the surface and drag around the edge of the blade. Flip the blade onto the opposite side and repeat. If you prefer you can do as Stacy suggests and clamp the rod to the surface and drag the blade around it. Same difference. Works just as well and probably as cheap a solution as you're going to find.
 
Grizzly has a reasonable price height gauge. The drill bit works, but I use my height guage for other things as well. Like markin center on my guards and handles and to give me some reference lines on the handle for shaping. Lots of ways to do it. I don't regret buying mine.
 
I used the drill bit method until I picked up this little guy. I think I got it from USA knife maker, I'm not 100% though. Works pretty good on stock up to 1/4"
14371915338_8e08c3d14d_b.jpg
 
Sometimes I do the drill bit thing, but sharpen the shaft of the bit to a pencil point. The profile of the blade should be pretty clean by then (I go down to 45m) and colored, and the bit will do a few blades before going dull.
A lot of my bits have a flat, not strictly pointed tip on the business end, so I don't assume I'm going to get an accurate line- that's probably my poor sharpening technique.....

Mostly what I do is break off the end of one of my 38457 small chainsaw files, and sharpen it to a pencil point- it's already hardened, and all I want is a guideline- a center line works, or any two parallel lines to get the bevels started evenly.
This is the part where the blade has to be flat and straight to get it to come out right. :)
 
The replaceable carbide tip of a scriber is close to 1/8"

Work well using that "the drill bit way" on 1/8" material
 
It is actually from riverside machine $20. u.s.a knife makers has a nice one as does jantz.

flatblackcapo said:
I used the drill bit method until I picked up this little guy. I think I got it from USA knife maker, I'm not 100% though. Works pretty good on stock up to 1/4"
14371915338_8e08c3d14d_b.jpg
Click to expand...
 
You must log in or register to reply here.
Back
Top