LN 7 1/2 query?

Re: I've traded a couple emails...

Greg Sloop

>Later follow-up...

Just for giggles, I took a bit of time tonight to really compare the two higher angle blades I've got for the the LN #62. (Obviously, I need to mail you this piece so you can compare...but for my plane, sharpening skills, and user skill - as equal it's a good comparison.

I have:

One iron at ~35-36 deg + 12 deg bed = 47-48 deg total angle.

One iron at ~50 deg + 12 deg bed = 62 deg total angle.

The 50 deg iron was quite dull, comparatively. I took a couple of minutes and touched it up with the veritas jig on 4000 and 8000. It was pretty sharp. Not completely awesome, but pretty nice.

The ~35 deg iron had been done a few days ago, and was as uber sharp as I get anything. Really nice.

I did both sides of the board I'm going to send with the 50 deg iron. Took a little while, but was able to essentially get it virtually perfect.

Then I switched to the 35 deg iron. Used another piece of scrap QS Syc. to "test" on. With a bunch of fussing, I was able to get it smooth, but with a fair bit of tear-out. I adjusted it about as fine as possible and switched to the first piece done with the 50.

The first pass wouldn't catch any wood, so advanced the iron just slightly. Second pass caught more than I'd anticipated and created some pretty serious tear-out. (The mouth is finer than I ever use in this situation with the 50 deg blade - more open and it just gets worse.)

After skewing the plane, and tinkering with the iron depth to give the finest shaving possible(almost just dust...) and skewing the plane for every pass, I cleaned it up a fair bit. Still not good or great, but not awful.

The end result is that even spending at least twice as long on the 35 deg side (47-48 deg total) I wasn't able to even approach the clean surface of the 50 deg (62 deg total) side. And remember, that the 35 deg iron was significantly sharper and the mouth significantly finer/smaller and the shaving even finer, and still with these differences, I couldn't get it anywhere close.

So, I'll email you and get your addy. When I get a chance in the next few days, I'll mail it off to you and we'll compare.

What this does tell me is this. At least, given my amature skill level - I've had a "good" plane for less than a couple of months - i.e. the LN. Prior to that I had "modern" stanleys which boogered up nearly anything they even got near! - even with that "lower" skill level, getting good results isn't possible *for me* at 45-50 degrees total. Perhaps at 50, again with much fussing, *I* could get good results, but being able to easily go to ~60 total angle makes it a cinch for me to get fabulous results.

I know I'm rehashing the bevel-up vs. bevel down arguments, but the points isn't that one design is better per-se. If a bevel up plane could have many different angles easily they would be as versitile too. But it isn't that easy. So, since I can get that (many angles) with bevel up, I use it and I'm very happy with it. The point isn't that bevel up is better than bevel down. The point is that total cutting angle is really important, and that a bevel up plane lets you modify that quite easily.

(...and I'm skepical about back bevels for bevel down planes. But I have no real basis for making that assertion - just a hunch - which is a really poor decision making tool! LOL Maybe we can get Lyn to do that next! *grin*)

Anyway...

Cheers,

Greg

Re: I've traded a couple emails...

Rob Lee

>Greg -

You've just encountered type II vs Type I chip formation...it isn't the plane configuration at work - it's the blade angle the wood "sees"...

Type II chip formation starts about 60 degrees - which is why I've never quite understood why so many people go for a york pitch in a bevel down plane... 50 degrees is still type I, though tightening the mouth up helps.

Cheers -

Rob

Follow-up

Ted Owen, Moderator

>Thomas L-N is getting to work on one right away. I'm not sure we have worked out how best to arrange participation for those who are interested--whether you should let Robin know or contact L-N directly. Robin, should we contact you?

And of course, we still don't know all the other details such as delivery time, cost, etc.

I would suggest that however it's done, we should mention that we're all part of the WoodCentral Hand Tools group interested in a 7-1/2 with adjustable mouth. Thomas is aware of the discussion here. Or Robin can take care of that.

Thomas already has my name on the list.

Best, Ted

Re: I've traded a couple emails... *LINK*

Roger Nixon

>(...and I'm skepical about back bevels for bevel down planes. But I have no real basis for making that assertion - just a hunch - which is a really poor decision making tool! LOL Maybe we can get Lyn to do that next! *grin*)

Lyn has done this. In his comparison of high angle smoothers, note how he uses a LV 4.5 with a 15� back bevel.


Lyn's High Angle Smoother Study

Re: Follow-up

Martin from Granbury

>I would need to see a final price, but I am definately interested.

Re: Follow-up

Christopher Fitch @ Memphis

>Same here...

;)

Re: I've traded a couple emails...

Greg Sloop

>Thanks!

I had seen that, but just browsed it. I wanted to go back and re-read it. I'll will do so.

In summary, it appears as though the back-bevel *is* effective. How effective it is compared to the same increase in angle for a bevel up iron isn't known, but I think we'll get an idea when Lyn get's his newest research published!

Thanks again,

Greg

Re: Follow-up

Greg Sloop

>I'm very interested, obviously.

I don't want to bug anyone needlessly via email, so if you don't mind, please let me know who and/or when I should email someone at LN or elsewhere.

Thanks,

Greg

Re: I've traded a couple emails...

Greg Sloop

>This progression seems to be fairly linear though too.

at 37 deg, I might as well be using a screw-driver.

at ~47 deg, it's much better, bit still an awful surface IMHO.

at 52 degrees it's almost perfect, but still small tear-out throughout.

at ~62 deg, it's pretty easy to get a perfect surface. It can even get difficult to tell which way the grain runs predominately as it planes nearly equally as well in either direction.

(If TLN would be so kind as to gift me another iron *grin* I'd be glad to try 55-57 deg and see how that works out. I just hate to keep re-grinding them to different angles all the time. Going up's easy. It's coming back down that is a "grind.")

So, it seems as though Type II chips don't just start showing up at a specific angle, but on a continuum. (I've read the chip formation types info in the back of your Dad's book BTW, though I don't pretend to understand all of it.)

So, york pitch should make some difference, at least in my exp on this current project. It probably won't make it perfect but it will be better.

Am I understanding you correctly?

(Perhaps we ought to take this to a new thread?)

Thanks,

Greg

Re: I've traded a couple emails...

Rob Lee

>Greg -

There isn't really a tremendous body of data to work from here, and chip formation angles will vary from wood to wood.

Generalizations I'd make are:

A back bevel works at least as well as a change in bed angle - and possibly better if not perfectly bedded, as a blade more in-line with the applied force can resist chatter better. (note - an adjustable mouth is necessary if using back bevels)

A bevel up plane will work at least as well as a bevel down plane with the same effective cut angle - same reason as above...

I would also note that better results may be reported using planes with a very tight mouth, and lower effective cut angles - but I infer that this is a result on "emulating" a type II chip, as the narrow mouth opening forces the chip to fracture nearer the blade edge.

Cheers -

Rob

Robin has started...

Ted Owen, Pittsburgh

>a recap thread above. Best to respond there, I'd say.

I don't yet know about price, but we'll know soon. In any event, while it will be more than a 7-1/2, the piece will have historical value. Already I can hear it calling my name.

Guess the slope remains slippery even after you think you have about everything you need. : )

Best, Ted