shooting boards

[Phil Pascoe]

I was doing a little research and came across this (not that Cosman is my favourite) -
https://www.youtube.com/watch?v=n2yZuylIB1o
I thought the point made at about 5.50mins was interesting, and something I hadn't thought about before. It made sense to me.

 

[sunnybob]

I'm confused.
he says to make the board crowned, rather than cupped. But then says cupped is bad but crowned is good. How can either of those circumstances affect the board to be cut because its in a different plane (horizontal v vertical type plane)?

 

[Phil Pascoe]

Because if the board is cupped the plane can ride on two narrowest parts of the side and can tip slightly. It it's crowned the widest part of the side of the plane is bound to be in contact. It made perfect sense to me.

 

[Racers]

Don't glue the two parts together then it won't warp.

And you can cut a dust groove in the bottom board where the fence board meets the bottom, so no dust/shavings can get trapped in the corner.

You can also trim the top board when it gets worn.

Pete

 

[John15]

I've got the same small strip detail as Rob to stop the plane taking shavings off the fence. I expect most people have the same. Works well.

John

 

[custard]

I understand why he advocates a crowned board, but I wonder if it's "overthink"?

My planes have a lateral adjust lever, so do his, that compensates if the plane tips back. Plus, if the lateral lever isn't carefully adjusted then it will introduce an error way bigger than any cupped/crowned board error!

If I'm shooting with a cambered iron (and let's get real here, it's actually pretty tricky to sharpen without introduce some degree of cambering) then I adjust the lateral lever so that the apex of the camber when the plane is sitting on the shooting board coincides with the centre of the workpiece.

Each to his own, but this approach works for me. Dozens of times per year I use a long shooting board that runs along the bench to shoot the edges of narrow stock for drawer sides and drawer bottoms, this technique delivers shot edges that permit ultra reliable edge jointing.

 

[sunnybob]

Still dont get it.
He's talking about a vertical rise (or fall) of the board. The plane slides horizontally along the edge of the board. The plane base is 2" plus wide. just how high is this cupping going to be to make the plane move out of true?
And however out of true it might be to start, several sweeps of the large plane will bring it back to to flat anyway.
A shooting board doesnt even need a lower rubbing strip. the plane will cut its own strip very quickly.

 

[Phil Pascoe]

I understand why he advocates a crowned board, but I wonder if it's "overthink"?
My planes have a lateral adjust lever, so do his, that compensates if the plane tips back.

I think the point was that it could tip slightly without your noticing it. If you're aiming for perfection (which by using it in the first place you are) why allow this risk if you can prevent it? As he says it's a very, very slight bow - so it's more ensuring there isn't a bow in the other direction than anything else.
You are of correct about the lateral adjustment - it doesn't matter whether the side of the plane is square to the sole, it can be compensated for and should always be checked anyway.

 

[woodbloke66]

Each to his own, but this approach works for me. Dozens of times per year I use a long shooting board that runs along the bench to shoot the edges of narrow stock for drawer sides and drawer bottoms, this technique delivers shot edges that permit ultra reliable edge jointing.

Same here, but mine gets used for a lot more than just narrow stuff. As I don't use a tablesaur, any components that need to be identical or made to an exact length are done on the shooter, even the top and bottom of my current job which are 380mm wide and over a metre long - Rob