Plane iron testing plan (Was: Infill plane) *LINK*

disagree with premise

bill tindall

>Steve Elliot has demonstrated conclusively that plane irons get dull. And when they get dull this dullness affects the quality of the planed surface, as well as the force necessary to push the plane, factors of primary importance to practical users. Change in clearance angle will certainly correlate with these data, but I don't believe that changes in clearance angle are the primary effect, nor the most fundamentaly important variable to measure.

Steve's data quantitatively measure wear rate and wear rate is the variable of primary importance in determining practical plane iron performance as a function of planing time(use).

I can see where the bedding angle would affect the wear rate of the edge, but I can't imagine that the details of the rest of the plane would affect the wear rate nearly as much as the properties of the steel, for example. Therefore, the details of the plane would be a secondary effect, at most. As such, it is not the place to spend time studying until the more important effects are understood- metal composition, sharpening, bedding, bevel angle, others?.

Re: disagree with premise

Joel

>"Steve Elliot has demonstrated conclusively that plane irons get dull. And when they get dull this dullness affects the quality of the planed surface, as well as the force necessary to push the plane, factors of primary importance to practical users."

I don't think anyone is arguing against that. THe question is if the plane body, fit finish, geometry, etc have any effect on how well that dull iron works. that is the kind of surface it produces. To me this is the most interesting part of how planes perform. I have a post-war Norris panel plane, which was always a good plane but was recently upgreated to a tighter iron and I use it all the time. on maple you can see visible to the naked eye nicks and gouges in the iron but the plane will still perform respectibly. This is what I love about it. (I have other Norris plane planes but this is the one I actually use. Except for the previous owner stripping off most of the ugly brown paint it has never been tuned or touched.)

I think Brent wants to extend his testing from looking at the iron to a more accurate picture on the effect a plane has on effective cutting ability as the iron wears. It's a really difficult test to do but it's very interesting if done well.

Re: disagree with premise

Greg Sloop, Portland Oregon

>[Sarcastic humor]

But, all that testing, and the details and discussing such technical trivia - it just makes my head hurt! I'd just rather caress my planes in ignorant bliss.

Just think of the children!

[/Sarcastic humor]

No, really honestly, I think this is a great idea. Just from pure speculation, I wonder if LABU planes would be more prone to this type of "problem" than HABD designs.

It would seem difficult to "shim" the bed to increase the angle though. How do we propose to do that?

Cheers,

Greg

Re: disagree with premise

Joel

>Very easy, just stick a bit of veneer near the top of the bed. (feather it if you are really concerned). You don't even have to change the way you grind your plane irons.

Re: disagree with premise

Greg Sloop, Portland Oregon

>I don't think this will work in any of the LABU designs, though it might with the LN62.

The LV adjuster design and LN 164 adjuster will probably have difficulty with this.

I understand that probably this testing isn't going to be done on LABU, but that is primarily what I had in mind. On BD planes, as long as the veneer remains thinnish, I expect it will work fine, though it may change the bedding enough (perhaps detrimentally) to taint the validity of the test - dunno tho - just musing.

Cheers,

Greg

OK, how about this premise

Brent

>Before the new premise, in response to your disagreement, a note on Steve's site. I spent a little time (well, quite a bit of time) - a lot has happened there since last I looked. The new sharpening station for use with stones is really something.

Your exception seems to be to my claim that use does not dull an iron! Wish my post did not read that way.

I believe that Steve's string test will produce about the same result for all blades sharpened well to a particular included angle, when freshly sharpened.

When I sharpen a blade for a test, the included angle is around 35 degrees. As the blade is used, the wear bevels on the front and back probably add as much as 15 degrees to the included angle.

What I meant was that when the plane appears dull at the standard bedding, you could increase the bedding and it would cut the same as a blade just sharpened to this larger included angle at the same bedding angle.

This claim does not extend to the A2 blades that experienced a lot of chip out. Steve appears to be getting more chip out of more types of blades than I get - his cherry must contain more hard bits than my douglas-fir.

On a slight side note, Steve gets different results (appearance) depending on the abrasive. In my experience, the 0.5 micron 3M paper produces the same surface on all steels (haven't tried a couple of his specialty steels though) with fewer scratches in the final micro bevel. It could be that the 0.5 micron abrasive, chromium oxide, is enough harder than all of these steels that it is able to produce the desired finish.

Re: Plane iron testing plan (Was: Infill plane)

Don Thompson - Cutler Ridge, Florida

>Why would using a different plane affect blade durability?

Some time ago, one of the fellows (pardon me if it was you or one of the other posters in this thread) on Badger Pond, I believe, made some conjectures and was making efforts to prove that vibration frequencies affected plane performance.

It would not be a great leap to suppose that some vibration modes would increase blade edge wear and/or failure.

IIRC, all sorts of variables in plane design and manufacture affected the vibration. Hence, it would not be completely without merit to guess that blades might wear differently in different planes.

I look forward to seeing the results of your testing!

Re: Steve's results?

paul womack

>Steve Elliot has demonstrated conclusively...

Are Steve's results on a website anywhere?

BugBear

Website Link

Steve Elliott

>The results are incomplete, but I have been posting partial results to help get the site organized.

Re: Website Link

paul womack

>The results are incomplete

Like all research (and websites) incompleteness tends to be a perpetual state :-)

BugBear