Open Source Hollows and Rounds: Ironing out the Details

Continuing in the saga for a method for making "user" grade side escapement molding planes. This time I chase the gorilla in the room, the iron.

The irons in a traditional set of H&R planes are pretty intimidating to any wannabe non-blacksmith plane "enthusiast" like myself. Think about the processing required for traditional English H&R (18X):

Material selection

Beyond the O1 A2, PMV-11, R2D2 metallurgy stuff, there's the sizes. 1/8"- 3/16" is typical thickness, check. Since the name of this game is "frugal" To me it sure seems like you'd want to minimize waste and the amount of pieces of tool steel purchased. This leads to going after a very wide bar as a blank like this McMaster #9516K517 and then nesting your irons by rotating H&R 180° as opposed to many varying widths of steel strips.

Nested, still some waste in the centers

Cutting out Blanks

Ideally these could be done with a CNC laser or water jet cutter. (If you have one laying around.) This is a de-facto production method at the corporation I work for (but I don't have access, and side-job personal work is frowned on there #fired) I always thought if I were making a traditional set, I'd source the blanks laser cut with the size and shape marked decoratively in the corner for easier visibility and extra cool factor. (I have so many ideas, eventually one will be good.)

Given "users" don't typically have lasers available, that means hacksaw or angle grinder with cutting wheel. Now remember, this is not a simple cut to length/width job, but instead a wide bit and narrow tang. (Ideally both varying by plane width). Sounds like work.

Taper

To me this seems like the scariest part, though in reality, most of the material removal is at the narrower tang portion. I suspect a magnetic jig that would register off the inside corner could be used to coarsely (and medium-ly and finely) linish them on a common bench top sander. 

This isn't absolutely necessary (for instance Philly planes doesn't currently do this) but there are good reasons to do so:

• Why Tapered Irons from Joel@TFWW
• Excellent old discussion of tapered irons @Handplane Forum

Shaping Profile

This is another laborious part to match the sole. Not really any way around this one. More grinding.

Heat Treating

Scary, but it involves fire and possibly baking Ghiradelli double chocolate brownies (tempering)  so sign me up.

Sharpening

Not your average 1/2" chisel. I don't have a dog in the sharpening race, let's just leave it at that. 

Skipping Ahead

There are a couple of sources to acquire them "ready to go":

• L-N
• Philly
• Corradi

But you still are going to be doing the shaping, heat treating and sharpening on your own. These are certainly not crazy priced given the pre-work already done, but it's still a decent chunk of change for soft tool steel, and raises the expectations for the planes made, at which point you might as well go whole hog with the traditional methods in my mind.

So the design targets for the plane should revolve around the constraints of the "ideal" irons which would be something like:

Parallel in thickness (as they come from the steel mills)

Parallel in width to make them require less processing with limited metalworking tools

Much shorter in length to reduce material usage. 

• Less material and complication in a Krenov vs Stanley iron, despite the thick iron goodness.
• Use a common width of steel for bit length so the whole set can be made from one piece of tool steel.
• Stanley #45 uses shorter, simpler irons
• Bridge City Toolworks has a unique solution with its hp-6v2 irons

In my next post, I'll show my first frankenplane concept(s) that attempts to accomplish these goals. 

To get there, I've turned to an antique panel gauges, lifting devices and IKEA... I'm hopeful to get something usable slapped together to do some recon with the master plane makers at Handworks (next week!), but I'm also supposed to be demolishing my kitchen this week too.