Lapping plane soles works!!!

[bugbear]

but it's not easy.

Yes, the obsessed proponent of removing metal merely marked by a reference surface now acknowledges that "conventional" lapping can be made to work.

However, the overheads and precautions involved are ... remarkable.

http://www.sauerandsteiner.com/news/200 ... sucks.html

(that site carries a statutory drool warning)

Edit: for infrequent visitors, here's my preferred way:
http://www.geocities.com/plybench/flatten.html

BugBear

 

[Paul Kierstead]

I have visited his shop and they are remarkably big surfaces, built on quite nice cabinets I must say.

 

[woodbloke]

but it's not easy.

Yes, the obsessed proponent of removing metal merely marked by a reference surface now acknowledges that "conventional" lapping can be made to work.

However, the overheads and precautions involved are ... remarkable.

http://www.sauerandsteiner.com/news/200 ... sucks.html

(that site carries a statutory drool warning)

BugBear

BB - thanks for that, is now on 'favourites' as I have another plane to do later and as you correctly say...droolworthy - Rob

 

[dchenard]

The plane on the top of the page looks like it was made for Tony the Tiger :mrgreen:

You know what they say about Konrad's planes... They're grrrrrrrreat! :lol:

DC

 

[newt]

In this months F&C there is an article on Karl Holteys planes. The interview revealed that if the sole is convex the chances of getting this flat by lapping on a flat abrasive is remote, concave you stand a chance as there should be no rocking. I had some long discussions with woodbloke on this subject when he was making his long woody. Rob solved the problem by first flattening with a jointer, but of course that would not be possible with a steel plane.

May all your soles start concave.

 

[dunbarhamlin]

My way past a convex sole is to lap lengthwise on a strip narrower than sole (and then if bad across on a strip shorter than the sole as well) - similar effect to stop shavings before the final full length passes, and gives multiple highs for stability instead of rocking around on the the apex of the convexity.

 

[bugbear]

In this months F&C there is an article on Karl Holteys planes. The interview revealed that if the sole is convex the chances of getting this flat by lapping on a flat abrasive is remote

absolutely - not much of a secret "revealed" there!

The same difficulty applies to the "taking a print" stage of my process, but is easier to solve, since the printing process is much (physically) simpler than the lapping process.

Ultimately, as has been said, the easy way to resolve a convex is to make a concave, by brutal means if neccessary, then work on the concave sole!

BugBear

 

[woodbloke]

In this months F&C there is an article on Karl Holteys planes. The interview revealed that if the sole is convex the chances of getting this flat by lapping on a flat abrasive is remote, concave you stand a chance as there should be no rocking. I had some long discussions with woodbloke on this subject when he was making his long woody. Rob solved the problem by first flattening with a jointer, but of course that would not be possible with a steel plane.

May all your soles start concave.

Pete - as we discussed on that day, probably the only really effective way to flatten a convex sole is to use engineers scrapers to scrape away the high spots and then test on a reference surface like this one if the plane is anything longer than a No4 - Rob

 

[Philly]

Waka and I had the pleasure of a few hours chatting to Konrad and prising useful information from his brain. He was kind enough to walk us through the making of one of his planes - I was amazed to find out that the only metalwork machines he owns are a drill press and bench grinder!! :shock:
The lapping table have huge marbles beds which he machined super flat at a local machine shop - a great way to get a huge surface plate.
Cheers
Philly

 

[Paul Kierstead]

Ultimately, as has been said, the easy way to resolve a convex is to make a concave, by brutal means if neccessary, then work on the concave sole!

Interesting idea; this is basically the idea of taking stopped shavings and then a through shavings (conceptually anyway).

Maybe it is time to prod Konrad on the subject; he most definitely ships all his planes dead flat, and the flattening regimen is definitely lapping, and he does some quite long planes, so... I wonder, is he just skilled enough to not make things worse, or does he always endeavor to err on the side of concave during fabrication, or does he use your method.

 

[dchenard]

Ultimately, as has been said, the easy way to resolve a convex is to make a concave, by brutal means if neccessary, then work on the concave sole!

BugBear

And how one does that? What kind of brutal means :shock: are we talking about here?

DC-C

 

[Jake]

His testing methodology, at least as demonstrated in that article, only proves the absence of convexity as far as I can see. Not that I doubt the things are more than flat enough^100.

 

[David C]

We have lapped literally hundreds of planes in my workshop, and Konrad has mentioned every detail that we have discovered over the years, except that with very hard old cast planes we choose to start with 60 grit blue Zircionia Alumina cloth backed abrasive.

BB's method is superior but this one works quite well enough if sufficient care is exercised.

I will just mention that if anyone thinks surface grinders are the answe, they are not! (Heat, clamping internal sresses and distortion being the main issues.)

best wishes,
David Charlesworth.

 

[bugbear]

Ultimately, as has been said, the easy way to resolve a convex is to make a concave, by brutal means if neccessary, then work on the concave sole!

BugBear

And how one does that? What kind of brutal means :shock: are we talking about here?

DC-C

Oh, really brutal. Like taking a 2" square sanding block, wrapping 80 grit abrasive round it, and hacking away some metal from the middle.

The concavity doesn't need to be accurate...

BugBear

 

[dchenard]

I will just mention that if anyone thinks surface grinders are the answe, they are not! (Heat, clamping internal sresses and distortion being the main issues.)

best wishes,
David Charlesworth.

Someone forgot to tell that to the machinist who did my Stanley #8 :wink:

To be fair, the plane was convex to start with, the machinist turned it concave inadvertently (not enough support I assume), on the second try he got it right.

DC-C

 

[bugbear]

I will just mention that if anyone thinks surface grinders are the answe, they are not! (Heat, clamping internal sresses and distortion being the main issues.)

best wishes,
David Charlesworth.

Someone forgot to tell that to the machinist who did my Stanley #8 :wink:

To be fair, the plane was convex to start with, the machinist turned it concave inadvertently (not enough support I assume), on the second try he got it right.

DC-C

Yeah - I think what DC(Devon) meant is that there's more to it than just throwing a plane in the vague direction of a surface grinder and turning it on.

BugBear

 

[dchenard]

Someone forgot to tell that to the machinist who did my Stanley #8 :wink:

To be fair, the plane was convex to start with, the machinist turned it concave inadvertently (not enough support I assume), on the second try he got it right.

DC-C

Yeah - I think what DC(Devon) meant is that there's more to it than just throwing a plane in the vague direction of a surface grinder and turning it on.

BugBear

And you're probably right, I just like to needle people once in a while :wink:

The machinist I went to had done planes for other members of our association. I'm not sure I'd go to some unknown chap who's never done it before, as there's not a lot of metal to play with...

DC-C