Sen

[Matt River]

Does a modern version of the sen exist? Wondering if I should look at extreme tool steel or repurpose carbide for a scraper. Also wondering if sen is always used as active tool on a clamped workpiece or if can be setup as a jig through which a blade is pushed. Have a number of books on traditional Japanese techniques but not in depth enough, any books or resources that are detailed?

 

[ron_m80]

I use a HSS parting tool from a lathe for this type of thing. It really helps me shape clip points. (especially since I don't have a running grinder at the moment, but looking at the clip points that are made with grinders it might be the better way still)

EDIT; I don't know if a jig would work, controlling it by hand isn't too bad.

-Ron

 

[Matt River]

Jig idea is simple, sen standing upright next to a register type of guide for grooves/fuller.

 

[ron_m80]

Oh, I forgot, Stacey did mention it was used for grooves, more so than flats if I recall now. I use the parting tool to help flatten high spots on the blade, and cutting in clip points, not for fullering.

If you wanted to cut a fuller, I would use a regular lathe bit ground the shape you desired, and fit into your "gig".

You could use a carbide insert type;

Or grind down a more typical lathe bit;

Just my opinion, no experience cutting fullers, like I said I use the parting tool for extreme shaping, and shaving high spots.

 

[Stacy E. Apelt - Bladesmith]

Yes, those replaceable carbide and synthetic PCD diamond inserts and a tool holder make a great fullering sen cutter. These tools can be as fancy as you want, with screw clamps and adjustable guides ... or as simple as a piece of wood with a square hole in the center and a wedge tapped in to hold the cutter.

Some folks use a sen that is like a draw knife to remove metal from flat surfaces. With skill, you can cut shavings of metal rapidly.

It would not work right to draw the blade across the cutter. You need to constantly adjust your angle as you cut and chattering would be a big issue. These draw knife type sends are usually made from tool steel or old files.

In the modern shop, a grinder and a 36 grit belt will remove steel faster and with more control, so a sen is more of a traditionalist type tool. The fullering sens are good tools to have.

 

[Matt River]

Right now a current project application is low tech but accurate marks on adjustable height wheel hoe cutters. Likeva motise gage with used circular saw tip, want grooves to interlock with prototype height mechanism. It is a blade... much of my edged work is agricultural in natural.

Thanks Mr. Apelt for the in depth fullering description, also make vintage military inspired knives, sounds exact on for several projects. Great tool ideas for small shops.