Sole flat enough?

[matthewwh]

Karl Holtey certainly does not agree with this thesis. The 98 and newer version have blade support solely at the heel of the bevel and a single point pillar further back.

I had an infill plane once where the timber had shrunk and the heel of the bevel was not supported. It was unuseable.

The bend imparted to the blade by 95% of all capirons seems to be a good thing. Just an alternative point of view.

Best wishes,
David

Alternative views always welcome!

I would point out though that Karl uses incredibly thick cutting irons and very low profile cap irons which suggests to me that he is designing to maintain as flat a surface as possible. I can see the attraction of his tricycle bedding arrangement which provides failsafe stability in the same way as a milking stool - provided that what you are clamping to it has mass and stability engineered in already.

Clico freely admit that their solution is over-engineered for standard use, but when you are using steeper angles for example it's reassuring to be starting out with something that is built like a tank.

 

[woodbloke]

woodbloke, are you getting paranoid yet? :lol:


Cheers, Vann.

Moi?....Noooooooooooooo 8-[ 8-[ 8-[ 8-[ 8-[ 8-[ :lol: - Rob

 

[bugbear]

Karl Holtey certainly does not agree with this thesis. The 98 and newer version have blade support solely at the heel of the bevel and a single point pillar further back.

I'm always nervous of disputing plane information with someone who's thought about it as much as DC, but...

...isn't the #98 bevel up, with the "back" of the blade bedded on a flat bearing surface?

AFAIK the "three point" bedding is used on (at least) his A6 and A13.

BugBear

 

[David C]

Bugbear,

You are of course quite right.

The thought that was going round in my head was that it is a good thing that the conventional chipbreaker bends the blade slightly because we then know that the heel of the bevel is properly supported, which is a good thing.

Blades are generally not as flat as manufacturers would like us to think and Frog surfaces are very variable.

Best wishes,
David

 

[woodbloke]

The thought that was going round in my head was that it is a good thing that the conventional chipbreaker bends the blade slightly because we then know that the heel of the bevel is properly supported, which is a good thing.

Blades are generally not as flat as manufacturers would like us to think and Frog surfaces are very variable.

Best wishes,
David

...which is one of the points I was trying to make. The crucial bit is the area where frog, blade, chipbreaker and lever cap iron all meet in one thick steel (or iron and steel) sandwich. That's the area where contact must be maintained 100% across all mating or touching surfaces and what happpens further up the frog isn't too important - Rob

 

[Alf]

I also did some planing with my 1910 patent Bailey No 8 today. It amused me no end to find that the blade seat of the frog is one continuous flat casting (no relief hollows here) I wondered if Leonard Bailey really did intend the blade seat to be only at the edge, when it was actually bedded on a huge flat area. Or perhaps that was some misinformed fiction someone has come up with.

Dunno about Leonard, but iirc Rob Lee has voiced amusement that we get all excited about the machining over the whole surface of the blade bedding area when actually it's machined so the iron does indeed bear on it at the mouth rather than all over. At least I hope I'm not putting words in his mouth - but damned if I could find the comment when I looked for it.

Never, ever rely on my memory; I mis-remembered it. So from the horses mouth:

Bedding area IS flat... what people miss is that the adjuster sits a wee bit proud of the bed - so the blade really sits on the adjuster, and the area back of the plane mouth...so the locus of primary contact (before blade deflection from the lever cap) is a line across the mouth, and a point at the adjuster. The lever cap will flex more of the blade into contact with the bed - with the most pressure exerted at the mouth.

Bed area is something people look at, and figure that more is better... they never actually look to see if the blade actually contacts the entire area..

 

[Paul Chapman]

Well, I reckon he's wrong, Alf. Just checked a few of my planes and the adjusters fit inside the slots in the blades, allowing the blades to sit firmly on the bed, clear of the adjuster.

Cheers :wink:

Paul

 

[bugbear]

Well, I reckon he's wrong, Alf. Just checked a few of my planes and the adjusters fit inside the slots in the blades, allowing the blades to sit firmly on the bed, clear of the adjuster.

Cheers :wink:

Paul

Yeah - it's quite well known (depending on the circles you move in ;-)) that some of the lash in a Bailey's adjustment mechanism comes from slack in the fit of yoke to cap-iron.

Now, Mr Lee ain't dumb, so I assume he meant something else. Back to you, Alf (or Mr Lee) .

BugBear

 

[woodbrains]

The bedding area is flat... what people miss is that the adjuster sits a wee bit proud of the bed - so the blade really sits on the adjuster, and the area back of the plane mouth...so the locus of primary contact (before blade deflection from the lever cap) is a line across the mouth, and a point at the adjuster. The lever cap will flex more of the blade into contact with the bed - with the most pressure exerted at the mouth.

Bed area is something people look at, and figure that more is better... they never actually look to see if the blade actually contacts the entire area..

I can't follow this either. There is no reason why the adjuster pawl should lift the blade set from the bed. It just sits there with a little downward pressure against the lower edge of the slot, assuming that the operator adjusts the the plane to advance the blade, as you should. If the rear end of the iron was lifted off the bed by the pawl the contact of the front edge would literally be only a fine line. The blade would chatter like fury. Even if the lever cap put more blade in contact with the frog it would be doing so through the LOOSE centre screw and bit of tin spring behind the lever. Lots of places to encourage vibrations.

I only know that my planes perform extremely well, with 2 piece cap irons and flat frogs. Nothing bent into tension, and being pressed back flat again with more spings and levers. We should be trying to emulate the situation in wooden planes of old (still the simplest and best). Their frogs were flat, their irons heavy and their wedges designed to impart pressure over a large area of the iron to contact a large area of the frog. Chatter free bliss!

Best wishes,

Mike.

 

[Alf]

In the Veritas planes, chaps! ](*,)

 

[Paul Chapman]

Ah, it's all becoming clear now. Just had a look at the instruction sheet for one of the bevel-up planes on the LV website, and Rob must have been referring to the blade sitting on the Norris-style adjuster.

Cheers :wink:

Paul

 

[David C]

Yes, blades surely sit on the top of the frog in Bailey planes. You may well see marks on the opposite face of the blade which show exactly where contact areas are.

David