A Little Scraper Plane

[Leigh Betsch]

I just finished making this one. I call it my Texas Scraper. Texas mesquite body, Vera wood sole (thanks Dale), O1 iron. Bedded at 95*, with a 10* back bevel. 30* bevel down or should that be bevel up since it's 5* over center, or I'll just say bevel towards the frog.
When I first tried it out it pretty much sucked and I was thinking of ways to re-bed it at 50* and turn it into a smoother. Then I tried it with a burr and that sucked. So I added a 10* back bevel to the non-bevel side and I found the sweet spot. I tried it out on maple, curly cherry, high figured walnut and bacote, all worked excellent.

[Paul Saffold]

Very nice. Did you make the blade?

[Leigh Betsch]

I did build a couple of dozen A2 blades a few years ago, but this one actually came from a box of misc steel that I bought from Steve Knight a few months ago. It's 1/4" thick. I did make the cap iron. It's made of 4140 pre-hard steel. Nothing to fancy. Brass would have looked better but I wanted more strength. I machine a pivot groove into it and it gets fairly thin but the 4140 pre-hard should b fine.

[george wilson]

4140 pre hard isn't very hard. You can drill,file,saw,or mill it. I have used it for making injection mold parts. You will need to get a harder piece of steel to hold an edge for long.

[Leigh Betsch]

The blade iron is O1 but the cap iron is 4140. The cap iron is about 32 Rc, the blade was heat treated when I got it from Steve Knight, I assume it's around 61Rc. Agreed 4140 is not hard enough for a blade but I think it should be fine for a cap iron. Since all that does is hold the blade in place and deflect the shavings out the top. I only reason I used 4140 instead of brass is because it gets down to .07 thick where I cut the pivot groove into it and I want something that wont bend when I clamp the blade down.

[harry strasil]

FWIW, I used pre hardened 4140 for making die parts for the hammer plant here years ago, you want sharp tools (bandsaw blade, end mills and drills, etc.) as dull tools will work harden the 4140 to the point that you need to anneal it to finish it. just my 2¢.

[Leigh Betsch]

Yes the 4140 will work harden. I don't use coolant on my boring mill, my hss boring bar got dull and work hardened a spot. I had to grind a carbide boring bar to finish the groove.

[harry strasil]

FWIW, I quit using liquid coolants with my Bridgeport and most drill bits in a drill press except for the really large ones 1 inch and larger and went to using very light compressed air. It moves the chips away and when using end mills or Woodruff key seat cutters, I could grab ahold of the cutters immediately after stopping the machine and they were almost cold. I am talking about air thru one of those segmented nozzle gizmos made to replace the rigid ones on oil cans, and a needle valve with just enough air going thru that I could barely feel it on my bare skin. A 96 year old retired machinist, but still active in his own garage machine shop put me on to the procedure. And its a lot less messy than continuous liquid coolant, and it doesn't make a cloud of very fine mist particles that you end up breathing like the misters do. I was truly amazed at how such an insignificant amount of force air could keep the cutter and work piece cool. Air also cools extremely well for deep boring in the lathe with a large drill bit in the tailstock.

[george wilson]

Yes,4140 will be fine for the cap iron. I didn't read your post correctly.