Putting Curve on Block Plane Blade

Re: Putting Curve on Block Plane Blade

Denis Ch�nard, Orl�ans, Ont.

>I would grind the iron to the proper curvature with a bench grinder, then on to the waterstones.

DC

Re: Putting Curve on Block Plane Blade

Frank D. in Montreal

>It depends how much curve you want though Denis...I know I can't put a one thou curve on blade right from the grinder. I use Charlesworth's old method of finger pressure and keeping track of how many strokes I've done. I can get verying curves depending on whether I start applying pressure to the sides of the blade on my 1000, 4000, or 8000 stone. I don't really measure the curvature but I can guess if I measure the thickness of the shaving in the middle when it tapers off to nothing (or almost) at the edges. It just takes a little practice, then you know how much camber to put on which blades (however much you want...try out the block plane and see id there's enough--if not then apply pressure for more strokes or start applying pressure on a coarser stone).

FWIW

Re: Putting Curve on Block Plane Blade

stephen wiseman

>Hi James,

I was able to put a "decent" curve on my 60 1/2 with strips of .008" card each side. About 12 strokes each side on an 800 King to gain a little more curve than the bench plane irons.Works great. Always could put an embryonic" (as David states) curve when grinding as well.

Best,

Stephen

Re: Putting Curve on Block Plane Blade

Denis Ch�nard, Orl�ans, Ont.

>I did put a camber on my Veritas low angle jack using the differential pressure approach, and it took forever, as you need a lot more curvature on the iron to produce an effective camber when the iron is bedded at 12 degrees.

Even for a "regular" bevel down plane, it is easy to create a proper camber on the grinder, provided you use a light touch. The trick is to check your progress often and to use an engineer's square (2-3" in size, depending on the width of the iron) to measure (sight) the size and symmetry of the camber. It's actually quite easy, but until I took that course at Rosewood I would have been loathe to try it, seeing it done in front of my eyes helped alleviate my fears.

On a different topic, check your e-mail... There's an Islander featured in the latest installment of Woodworker's Journal e-zine...

DC

Re: Putting Curve on Block Plane Blade

David Charlesworth

>James,

I think the light showing at the edge of mine, when offered up to a flat surface is about 10 to 12 thou".

This is quick to establish on an 800g stone with the plastic shim, even if your grind is straight. This stage gets a three facet approximation to a curve, which is then blended a bit with some extra stokes and point pressure form one forefinger.

A slightly curved grind speeds things further if you can do it. I exploit the slop in my Tormek jig, pressing on one corner while lifting the other.

People who find this slow and hard going are probably not grinding at a low enough angle, (approx 23 degrees).

I do the 800g work at 30 degrees and polish at 32 degrees.

best wishes,

David

Re: Putting Curve on Block Plane Blade

James Blandford-Baker

>Dear David et al

Many thanks for all that information; it is hugely helpful. I now know where to start (always the key in my experience!)

Best wishes

James