machining a wedge

[salvageclaus]

I am going to make a wood working tool called a Froe.
This was used alot over the last couple hundred years to cut roof shingles
Here is what the tool looks like:
'

Here is what the blade itself looks like:



I can build the blade no problem. It is made from 1/4" mild steel.
I do not have a machine tool to cut the edge on the blade. The edge is more like a wedge.
The angle is steep close to 45 degrees. Any suggestions on how to produce the edge with tools I might already have?

[theonlybull]

a grinder, some wheels. and some time

[Pangea]

I have made two froes in my life. Probably the most simple tool ever made. You can shape the edge with a file or a angle grinder. As mentioned, it isn't a sharp tool but rather made for controled splitting.

Good luck.

[salvageclaus]

How do you get a precise angle cut? I consider myself as handy as anyone with a handheld angle grinder or even a bench grinder, but without some sort of jig, you can't control the angle.

[BillDaCatt]

How do you get a precise angle cut? I consider myself as handy as anyone with a handheld angle grinder or even a bench grinder, but without some sort of jig, you can't control the angle.

Mark and scribe a line about 1/4" from the edge. Bevel it to that line, leaving a tiny amount of the cutting edge flat as a reference for your final edge, and check the angle. You should be close. Scribe another line 1/16" from the first and regrind if it is not right. Continue like this until you reach an acceptable angle.

Use a 40 or 60 grit flap disk to grind your angle. It will give you good control and a smooth finish. Finish lightly with a 120 grit flap disk to remove any scratches from the other disk(s) and to sneek up on your final line.

From what I know of "froes" the angle is not critical and it is intentionally a little dull. It is sort of like the edge on a hatchet or splitting wedge. It is there to get in between the fibers of the wood when you first hit it, nothing more. Once the blade is in a few inches, the rest of the split is a twisting motion with the handle.
Dave

[salvageclaus]

Mark and scribe a line about 1/4" from the edge. Bevel it to that line, leaving a tiny amount of the cutting edge flat as a reference for your final edge, and check the angle. You should be close. Scribe another line 1/16" from the first and regrind if it is not right. Continue like this until you reach an acceptable angle.

Use a 40 or 60 grit flap disk to grind your angle. It will give you good control and a smooth finish. Finish lightly with a 120 grit flap disk to remove any scratches from the other disk(s) and to sneek up on your final line.

From what I know of "froes" the angle is not critical and it is intentionally a little dull. It is sort of like the edge on a hatchet or splitting wedge. It is there to get in between the fibers of the wood when you first hit it, nothing more. Once the blade is in a few inches, the rest of the split is a twisting motion with the handle.
Dave

I can see that working for me. Thanks. Good tip on the flap disk to dress up the edge and polish.

[Gary Brady]

Lacking machine tools I would make a grinding jig out of wood. Use a table saw to get the angle and screw the blade to the wooden jig. That way you can grind and file flat.

[whateg0]

The sanding disk or flap sander is great and relatively quick. I agree that the exact angle is not that important in this case. If it were though, a jig and a hand held file would give you the most control, IMHO.

Dave

[vicegrip]

Hi , mild steel is not a good choice , got an old broken leaf-spring ....or buy a flat in O-1

5/16 thick X 2" wide or your metal to wood joint will loosen readilly , if the tool is to see serious use..........any weld method will work ...just let it cool slowly

aneal

harden full lenght

draw to medium blue

included angle to be 50 to 60 degrees.........I like 50

good luck .......I may still have the last one I made ....I'll pic it if I find it !!

[Blacksmith]

I agree with the leaf spring. For a lot of homemade tools, leaf spring or coil spring is a good substitute for tool steel. I have a few punches and chisels made from coil spring. Its really neat the first time you run the colors to temper it. (Heat to red, quench the business end, then quickly polish it with a file and watch the colors as the heat soaks in from the other end, then quench the whole tool at the right color.) By the way, I think the rocking action of using a froe to make shingles is the origin of the saying "to and froe".

[salvageclaus]

Hi , mild steel is not a good choice , got an old broken leaf-spring ....or buy a flat in O-1

5/16 thick X 2" wide or your metal to wood joint will loosen readilly , if the tool is to see serious use..........any weld method will work ...just let it cool slowly

aneal

harden full lenght

quench to medium blue

included angle to be 50 to 60 degrees.........I like 50

good luck .......I may still have the last one I made ....I'll pic it if I find it !!

I have been wondering about the angle of the blade as it attaches to the handle tubing.

I have seen some with a slight offset while others are straight.

[whateg0]

I agree with the leaf spring. For a lot of homemade tools, leaf spring or coil spring is a good substitute for tool steel. I have a few punches and chisels made from coil spring. Its really neat the first time you run the colors to temper it. (Heat to red, quench the business end, then quickly polish it with a file and watch the colors as the heat soaks in from the other end, then quench the whole tool at the right color.) By the way, I think the rocking action of using a froe to make shingles is the origin of the saying "to and froe".

That's interesting information. I shall have to try some of this. I have use leaf springs to make slappers before, but never thought of it as a "substitute" for tool steel. Perhaps I'll try using it for a blades in a shear that I made a while back. Also didn't know the proper way to temper something before. Thanks for posting that!

Dave

[Pumpkinhead]

By the way, I think the rocking action of using a froe to make shingles is the origin of the saying "to and froe".

Uhhhh, no, to and fro (no "e") comes from 'there and back' i.e. go to and return from, although not necessarily from the word 'from' but but from the Saxon word fra/o "back"

froe comes from frower, which comes from the middle english froward, 'turned away' (from the handle)

[coalsmoke]

How do you get a precise angle cut? I consider myself as handy as anyone with a handheld angle grinder or even a bench grinder, but without some sort of jig, you can't control the angle.

That's not necessarily true. I put a 33* bevel on my pipe pieces with an angle grinder no problem, and its precise. Get an angle finder, set it for 45* or whatever angle you want, and learn to use the grinder to your advantage.

[firebird77clone]

That's not necessarily true. I put a 33* bevel on my pipe pieces with an angle grinder no problem, and its precise. Get an angle finder, set it for 45* or whatever angle you want, and learn to use the grinder to your advantage.

I'm glad someone else cued into this comment of his.

The most precise and accurate machine tool in the machine shop is the surface GRINDER.

Now, you are not a Computer Numerically Controlled machine, but you Do have the same tool it has. A grinder. Tip for ya: if you got serious grinding to do, grab that big HE MAN grinder and put a 10" disc ( or larger ) and get skippy buddy. A 4" will get the job done eventually, but you'll have to be the judge of which one will tire out your arms first. Sometimes you can get quicker results with a cutting disc, compared to a grinding disc.

Just make complete, controlled passes of equal time and speed. Pass across the entire face of the object, and check your progress often.

There is no real secret to precision use of the angle grinder, but one item which must be emphasized is even repeated motion. I can use a 4" angle grinder with a thick disc to ACCURATELY remove the ridge of a brake drum. I have made many precision parts with just an angle grinder and a cutting disc. ( you be the judge of precision.. I say if it is closer than .1 it is pretty fair. )

anyway, the good ol' fashioned bench pedistal grinder is still around somewhere.