Bevel Up or Bevel Down?

[tja]

This might be nitpicking and I might have got it wrong, but doesn't skewing a plane mean changing the angle of the edge of the blade relative to the direction of travel of the plane in order to lower the effective bevel angle. On a ramped shooting board this doesn't happen, as the angle of the edge of the blade relative to the direction of travel of the plane stays the same.

Take

 

[Derek Cohen (Perth Oz)]

This might be nitpicking and I might have got it wrong, but doesn't skewing a plane mean changing the angle of the edge of the blade relative to the direction of travel of the plane in order to lower the effective bevel angle. On a ramped shooting board this doesn't happen, as the angle of the edge of the blade relative to the direction of travel of the plane stays the same.

Take

It's probably appropriate at this point to re-state the conclusions I reached with regard ramped shooting boards ...

1. A ramped shooting board is smoother (in use) than a flat shooting board.
2. A skewed cut (#51) is smoother than a straight blade (LAJ).
3. This is additive: a ramped board plus skewed blade is the best of the lot!

The full post (with experiment) is at https://www.ukworkshop.co.uk/forums/viewtopic.php?t=34664&highlight=

Regards from Perth

Derek

 

[xy mosian]

What a fantastic place to learn a great deal, thanks all.

Olly, I have never used a scraper plane so I'll happily take your word on how tricky they are to set up. I do have an 80, bought for use on Chesnut some years back. I cannot honestly remember how it was in use.

Matthew. I'm not sure just what is referencing the 'back' of the blade (normally no bevel?) in a Bevel Down set up. But I'm interested in the fact that someone else has thought to change the effective cutting angle by adding a back bevel to a blade used bevel down.
I haven't looked at the effect on cutting angle of skewing the plane during cutting. I assumed that most of the benefit I have been getting is from a slicing cut, from what you, and others, say this may not be the case.
I have two bevel up planes, the Record 311 has no lever operated lateral adjustment. The Stanley 060 has independant blade advance and lateral adjustment, perhaps not the best but they work. I take it from your words that this is not often the case.

tja, Take, As I said above my own take is that skewing the plane imparts a slicing action to the cut, which, first thoughts would suggest is also the case using a ramped shooting board. I must look into the whole thing regarding changes to the effective cutting angle etc., and slicing when my brain is clearer.

Derek, thanks for the reminders about your conclusions. Particularly the link to your post, I knew I had read it somewhere.

xy

 

[tja]

xy,

Slicing implies a movement other than perpendicular to the edge. On a shooting board, ramped or not, the movement is strictly perpendicular to the edge (assuming the blade's edge is perpendicular to the side of the plane, which is usually the case, unless you happen to have a #51 ).

Take

 

[xy mosian]

tja, Take, I hope that's right

This is how I see the action of using a ramped shooting board with a plane blade square to the direction of travel.

As I see it there is a small movement of the blade sideways to the axis of the board, this I would call slicing.

xy

 

[tja]

xy,

I'm thinking on my feet here :-k , but in your drawing there's no sideways component in the movement of the plane (marked "Path of Plane" in your drawing), thus no slicing. I think that the axis of the board, as far as slicing is concerned, is moot. As an academic exercise let's put the "Path of Plane" 89* to the axis of the board, the edge of the blade would still hit the wood headon, instead of it being the ultimate slicing action.

Take

 

[matthewwh]

I must admit I was looking at it from the perspective of a given point on the board being shot. If this passes up the bevel at any angle other than perpendicular to the cutting edge then the effective angle of planing has been lowered.

Take's point has really got me thinking though. I just did a quick empirical test and a straight or skewed plane both produce a straight, flat shaving, whereas slicing diagonally across the board produces a tightly curled spiral.

This suggests to me that Take is right and in the shooting board scenario a point in the shaving is still passing straight up the bevel at 90 degrees.

Having said that, a point on the finished surface (the bit that matters) is still passing under the cutting edge and under the top of the bevel at an angle other than 90 degrees, and Dereks experience tells us that the effects are similar to using a lower angle.

More thought required.

 

[xy mosian]

Take, I take your point, but given your scenario there would not be much cutting of the board.

Matthew, Thank you for looking into all that, and more importantly actually doing a practical test. As a man I respect used to say "When theory and practice agree you've normally done something wrong ".

More to the point I think we're getting to the 'whatever works for you' stage. That of course is true for most woodworking, but it is good to learn how others tackle the nitty gritty of this hobby/job of ours.

Mathew says "more thought required", I agree but my brain is hurting so I'll give it a rest and re-read Derek's post. Then all the rest of this post then who knows?

Thanks all.

 

[woodbloke]

my brain is hurting so I'll give it a rest
Thanks all.

Join the club...when the topic of ramped, skewed or whatever plane angles and convoluted shooting boards appears on the forum, my brain always aches. I use a straight forward ordinary shooter with a LN No 9...works for me - Rob

 

[Anonymous]

I use a straight forward ordinary shooter with a LN No 9...works for me - Rob

Ditto. Can't beat it :wink:

 

[wizer]

Pah use a disc sander, much more precise :-#

 

[Tom K]

Shouldn't Mr Maskery be giving one of his Bunteresque eulogy's at this point.
Crikey I thought it had been fully explained to you chaps. If it ain't skewed then it ain't a skewed cut it might feel like it but it doesn't fit the formula :lol:

 

[bugbear]

This might be nitpicking and I might have got it wrong, but doesn't skewing a plane mean changing the angle of the edge of the blade relative to the direction of travel of the plane in order to lower the effective bevel angle. On a ramped shooting board this doesn't happen, as the angle of the edge of the blade relative to the direction of travel of the plane stays the same.

Take

Correct. They're not the same as each other, but they're both beneficial to shooting.

BugBear