Thread: Low angle vs. High angle Planing
8th Jun 2004, 05:42 PM #1
Low angle vs. High angle Planing
Until Sunday, I was firmly of the belief that to smooth particularly cranky grain, you needed a high-angle plane or a scraper to avoid tearout.
At the Sydney show, I was talking to the guy at the Mik stand about his sharpening methods. He demonstrated the sharpness of the blade in his low-angle smoother by taking a transparent shaving off a block of tiger-grained hardwood (can't remember what it was) and then he put a piece of something that looked like the inside of a burl and did the same thing. It was smooth as silk and hard to see how it could be improved upon. Not the slightest amount of tear-out. He attributed this to the adjsutable mouth. He told me that all weekend he'd had people arguing that a high angle was required. He said to me "it doesn't matter what arguments you put up, here is the proof".
What do others think?"I don't practice what I preach because I'm not the kind of person I'm preaching to."
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8th Jun 2004, 06:07 PM #2
This is really interesting. What sort of plane was being used (did you take notice of the blade type?) Have a look at this thread
As you can see, I was using my HNT Gordon smoother and my Stanley #4. The Stanley #4 was delivering a better result than the Gordon. Theoretically this shouldn't work: The Gordon has a bed angle of 60° and the Stanley a bed angle of 45°. However, I reckon the Stanley blade was sharper. Further more, the Stanley is fitted with a Lie-Nielsen blade and chipbreaker, a very stiff and rigid combination.
Maybe the answer is that the most important issue is how sharp the blade is, followed by how rigidly held. There's no doubt that a small mouth is also important so the frog on an adjustable plane has to be set well forward (there's an old joke in there somewhere about the wide-mouthed frog ).
Complicated - isn't it?
8th Jun 2004, 06:54 PM #3
Lie-Neilson Low Angle Smoother
I also saw the guy at the Mik stand. He was using a Lei-Neilson low angle. It was a biblical moment watching that plane go thru a cranky grain. Timber looked a bit like a tiger Myrtle Burl.
Shavings were transparent like silk. The plane was a low angle Lie-Nielsen with adjustable mouth.
Here is the link to this plane --->
Last edited by GregLee; 13th Jun 2006 at 01:51 PM.Greg Lee
Old hackers never die, their TTL expires....
8th Jun 2004, 08:18 PM #4
8th Jun 2004, 08:55 PM #5
Rock star in hiding (SilentC)
Your in luck, the answers you seek should be found in the last two pages of this thread. (starting from Rockers post about back bevels)
Rob Lee himself dropped by to add a couple of words.
The man from MIK was right BTW, it seems that a small mouth helps a lot with the finish on difficult timbers.
So a loud-mouth-shnook like your self is in trouble.
8th Jun 2004, 09:55 PM #6
That's the one. I thought it might have been a Lie-Nielsen but I couldn't find it on the Mik site. The great thing about that plane is that it's designed for end grain work too. I'm hoping to source some woolybutt soon and I think I might 'need' one of these.
Col, I read your post and it was what prompted me to start the thread. It's not that the information we get is contradictory, it just seems that either there's more than one way to skin a cat, or some methods work better in some situations than others. Reading between the lines, the Mik guy was almost saying "this is the only plane you need for cranky grain". He didn't actually say that but... I wish I'd delved a bit deeper but I was just so gob-smacked that any hope of intelligent questions vanished.
Ben, thanks, I'll go over that thread again. I'm sure it's all in there, just have to get to grips with it all. Big mouthed shnook, huh? Why I oughta..."I don't practice what I preach because I'm not the kind of person I'm preaching to."
9th Jun 2004, 03:33 AM #7
Ok, this is going to confuse you even more.
There is no one plane, or one cutting angle, that is "best". It really comes down to the piece of timber that you are planing. Even within species, there is such variation of grain that it will respond differently to different planes. Hence Col found that suddenly his Stanley (45 degrees) outperformed his HNT Gordon (60 degrees) on a piece of Jarrah. This is why it is a good idea to have several smoothing planes at the ready ( or so I tell Lynndy ).
Rule #2: Straight grained timber will respond better to a low blade angle since a slicing cut is cleaner. Remember, the higher the blade angle, the more the blade cuts with a scraping action. A scraping action is often all that works on really cranky and wild grain. However the finish of a scraped surface will be less smooth that a sliced cut, producing (by comparison) a matt finish. So why then can a low angle plane cut wild grain so well?
Two reasons. Firstly, the mouth is closed down really tightly, and this permits very fine shavings only, and limited tearout as much as possible. And secondly, because low blade angle planes are not really low blade cutting angle planes!! These are bevel-down planes, and the effective cutting angle is around 45 - 55 degrees (depending on the angle of the blades bevel). And so we could enter the debate of which is better, bevel-up or bevel-down? I don't think we will go there right now.
I think that the advantage of low angle smoothers (such as the LN and the Veritas) lies with their versatility. It is possible to use them in high angle mode (with cranky grain) and low angle mode (on end grain). But don't see them as replacing other planes. I'd certainly like to have one. But it won't make the other planes I own redundant in the least.
Regards from Perth
9th Jun 2004, 08:50 AM #8
Derek, I agree with you on all your well-made points, but I can't see how we can avoid bringing the bevel up/down bit into the discussion. From a purely mechanical point of view, the bevel-up configuration seems to make good sense. You have the blade firmly supported almost to the cutting edge. With the bevel down, there is a lot of blade 'floating' between the bed and the cutting edge. Just how much depends on the thickness of the blade - (which has led me to query the rationale of thick blades on a number of occasions). The thin blades of most of the standard Bailey types rely on the cap-iron to pretension the cutting edge, or they won't work too well, as we all know. There's no doubt a slightly thicker blade gives a better 'feel' to the cutting action on harder woods, but I suspect this is soon balanced by the bed effect - (would be interesting to do some real science here, and actually measure the resonant vibrations with blades of different thicknesses in different planes!?).
I heartily agree with the view that a properly sharpened cutter with a well-set cap iron, and properly seated bed is the #1 priority for any plane. I well remember the first time I had a Norris thrust into my hands. "Here, try a REAL plane", was the owner's comment. Well, I was well aware of the reputation of Norris, and was expecting some sort of epiphany as I swiped it over the job I'd been attacking with my moderately tuned #4. Imagine my diasppointment to find it neither cut as sweetly, nor left as good a surface as the humble Stanley had been managing. A quick check of the cutter showed it wasn't sharpened too well, so I guess that was the main reason.
I've recently acquired a Norris of my own, and the disappointment continues! The cutter in it is way too soft - don't know if this is a lemon or if someone has done something unspeakable to it, but until I can get a decent blade, it's not going to displace either of the two Stanleys that currently do the job.
Yep, there's a heck of a lot more to what makes a sweet plane than the bed angle!
9th Jun 2004, 09:36 AM #9
Just on the subject of cutting angle, I'm not sure I understand why bevel down gives you such a steep angle. When the blade is bevel down, is the cutting angle not equal to the angle of the frog, or have I misunderstood?"I don't practice what I preach because I'm not the kind of person I'm preaching to."
9th Jun 2004, 10:05 AM #10
Cutting angle is what the wood sees as the blade cuts or splits it.
As far as I can see the wood doesn't care what the bed angle is.
You could mount a square edged billet in a low angle plane and you've got yourself a reverse angle scraper!
9th Jun 2004, 10:08 AM #11
I guess it was Phil that showed you his LN164. They work well and worth the investment. Like Derek said, I find some planes work better on different curly grained timbers.
It is for this reason I like to have several good planes at the ready but my LN164 is generally the first choice for difficult grain.
Have you ever seen one of Phil's block plane? He made a few of them and although I have never used one, I understand they work a treat.
Like all staff at MIK, Phil always gives excellent advice and is prepared to discuss the finer points of the product you are buying.
- Wood Borer
9th Jun 2004, 10:19 AM #12
WB, yes I think that was his name (I'm terrible with names). He knows his stuff.
I still have a problem understanding the cutting angle. If all other things are equal, I'd have thought that a bevel down blade would have a flatter cutting angle than bevel up. Bevel down, the angle between the front surface of the blade and the wood is parallel to the bed. Bevel up, it's the sum of the bed angle and the bevel on the blade.
So when you talk about cutting angle, is this the angle we're talking about, or have I missed something?"I don't practice what I preach because I'm not the kind of person I'm preaching to."
9th Jun 2004, 10:24 AM #13
Silent - here's a (very) rough diagram. As you can see, for a bevel-down plane with a parallel iron, the cutting angle is the same as the bed angle, unless you put a 'back-bevel' on it (i.e. hone a small bevel on the normally dead flat side of the blade).
For a bevel-down blade, the cutting angle is the bed angle PLUS the bevel angle. For a low-angle plane (usually bedded at about 12 degrees) the cutting angle becomes that plus the bevel angle (usually around 30 degrees after honing) making the cutting angle about 37 degrees. As derek has said before, this is not a lot different from your garden variety Stanley.....
For a 'standard' block plane, the cutting angle is about the same or slightly higher than a Bailey type.
Does that help??IW
9th Jun 2004, 10:26 AM #14
Yep, that sounds right (angle between front face of blade and wood)
Bed angle is important for bevel bown blades, but irrelevant for bevel up blades since you can change it by grinding it at whatever angle you like.
9th Jun 2004, 10:39 AM #15
What you are saying in that diagram is that the cutting angle is actually the number of degrees that the leading edge of the blade is off the perpendicular, not off the horizontal. So for a more acute cutting angle, the leading edge of the blade is actually presenting to the wood at a steeper angle.
A low-angle bed therefore has the opposite affect on cutting angle to what you would logically expect when it is measured this way. But why do we measure it from the perpendicular? It seems back to front to me... :confused:"I don't practice what I preach because I'm not the kind of person I'm preaching to."