Plane bevels

[woodbloke]

Mr C wrote:

Off stone guides are generally cumbersome in my opinion, and the £5-xx Eclipse clone from APTC does a fine job in this workshop. I apply finger pressure to the blade, near the edge, and keep the weight off the guide itself.

This certainly works exceedingly well on waterstones which must be the softest sharpening kit available. Diamond stones must be the hardest and I can assure you that there is absolutely nothing to worry about if you wish to use a guide on one of these.

I use an Eclipse clone honing gauge modified to Mr C's specification (as indicated in a very early edition of F&C, tho' don't ask me which one) and it is superb. If used as Mr C suggests a straight or cambered hone can easily be achieved by varying finger pressure during the strokes along the stone...try it out, it's one of the best honing guides out there - Rob

 

[Digit]

Thanks all.

Roy.

 

[bugbear]

Is it just me or had it been said before but I always thought that the main reason and advantage with any LA plane is better adjustment. Because of the low angle the blade has to travel further to protrude out below the mouth which means it much easier to set it for very fine cutting. Sorry for the lack of eloquence in trying to explain but I'm still half asleep.

One would hope that an intelligent designer would compensate for this (one way or the other) in the pitch of the adjustment screw.

BugBear

 

[bugbear]

While the subject of sharpness is being mentioned I'll raise another of my concerns.
Honing guides!
I can't get on with the damn things at all! As they all seem to run on the stone you are are running the guide on a surface that has probably been used to hone an edge already, and therefore probably not as level as we might like.
Also they shorten the stroke because of the space they take up on the stone and it is difficult to hone a wide Iron on a narrow stone.
Solution? I hope! This week I purchased a superfine diamond honing plate, as time permits I intend fixing it down on a wide base and making a 'saddle' guide that will straddle the plate and run on the base.
This way, if the saddle has the appropriate honing angle built into it, the angle is guaranteed, the width of the Iron is irrelevant and the full length of the plate will be used.
Anyone tried anything similar?

Roy.

Any jig that doesn't run on the stone will address this issue; a straddle can be made, but a simpler "long jig" has been the more conventional solution, e.g. the Stanley #200.

BugBear

 

[jonbikebod]

It is worth bearing in mind, if using an ‘off the stone’ guide with a water stone that the surfaces of the stone need not only to be flat but parallel to each other as well.
I have no idea how you would achieve that!
Not relevant with a diamond stone but others will be reading this thread as well.
Jon.

 

[bugbear]

I want something that I can drop the Iron on to and that automatically gives me the correct honing angle and a square edge.

A square edge is (at least partly) generated by your care; no jig (including my monster) is strong enough to forcibly restrain the strength of a human to sub thou tolerance; jigs should be considered as helping you to sharpen properly, not forcing you to.

http://www.geocities.com/plybench/tour. ... pening_jig

BugBear

 

[bugbear]

If I've followed you correctly Rob that still leaves the guide running on the stone, which is one of the things I wish to avoid.

Roy

If your stone is too uneven to run a jig wheel, it's probably too uneven to do a good job on a straight edged blade. If a running jig wheel is causing unevenness in the stone, there's waaay too much pressure on the jig.

BugBear

 

[Digit]

When I mentioned hollow I wasn't suggesting something akin to a model of the South Downs. I wonder how unflat a stone can be before it has any effect on the final product, the shaving.
The idea that the shallow angle is to help with adjustment may be relevant where such an adjuster is fitted but that simply would not apply on old wooden ones with a simple wedge.
I was always led to believe, right or wrong, that the bevel was reversed simply to prevent chipping, rapid wear, to what would otherwise be a very thin cutting edge.

Roy.

 

[Paul Chapman]

I wonder how unflat a stone can be before it has any effect on the final product, the shaving.

Provided you hone the blade by rubbing it straight up and down the stone, a stone hollow in the centre will result in a cambered blade, the degree of camber depending on the amount of hollow. This might be OK if you want a cambered blade, which can be useful in certain circumstances. Where you need to be careful is in wiping off the wire edge - you will need to ensure that the blade goes right across the stone to make sure that the wire edge makes contact with the stone without tipping the blade up and rounding over the edge.

Cheers :wink:

Paul

 

[bugbear]

When I mentioned hollow I wasn't suggesting something akin to a model of the South Downs. I wonder how unflat a stone can be before it has any effect on the final product, the shaving.
The idea that the shallow angle is to help with adjustment may be relevant where such an adjuster is fitted but that simply would not apply on old wooden ones with a simple wedge.

There are VERY few wooden planes with low angle beds, at least by metal plane standards. I think around 30-35 is as low a bedding angle as wood will tolerate.

Hence the "odd" design of wooden side rebates.

BugBear

 

[Derek Cohen (Perth Oz)]

Roy wrote:

When planing end grain the conventional wisdom is to use a low angle plane.
Now most low angle planes are used bevel up, whereas more conventional planes are bevel down!
A quick calculation suggests that from the timber's viewpoint there is little difference.
Any ideas anyone?

I've come in late on this discussion and, since I have not had much to say for a while, I feel inclined to say a little (also I am in the process of completing an article on shooting boards).

It is true, as Philly states, that a sharp blade is all-important. This can certainly overcome some of the effort in using a plane with a high angle of attack. But not all.

I use shooting boards a lot. I have a few. These include a flat board, a ramped board, and a Stanley #51/52 combination. I have used planes with high cutting angles, such as a HNT Gordon Trying Plane (60 degree bed) through block planes (light weight) and my favourite, the LV LA Jack (37 degree cutting angle).

All of them cut well but the low angle cut with greater ease and produce a smoother finish. Try an experiment in using a LV LA Jack and swapping 25 degree and 50 degree (or whatever you choose) blades.

Try this on different density woods as well. The harder the wood, the more you will appreciate the lower cutting angle. Durability of the edge is another matter all together.

The BU verses BD issue is also pertinent. Not because of the cutting angle, which can be the same for each, but because shooting end grain really tests the stability of a plane. Shooting end grain really penalizes a plane that has a poorly, or even, lesser bedded blade.

I have just completed the restoration of a Stanley #51 (http://www.wkfinetools.com/contrib/dCohen/z_art/rest51-52-p2/p2-rest5152-1.asp). In short, what I found was that the plane cut very poorly at the start of the tuning process as the blade was poorly bedded at the mouth. The better the bedding (the more I corrected the angle supporting the back of the blade at the mouth), the better the plane cut. No other changes were involved here.

The point is that a bevel up design supports a blade better than does a bevel down design. Thicker blades can overcome some of these differences. So can momentum.

Another thing I take issue with Philly is the idea that a heavy plane is in some way superior to a lighter one, I just find it harder work.

Roy, I must politely disagree once more.

Heavier planes simply provide greater "glide through" ability. No where more is this evident than when shooting end grain.

I can compare a LV LA Jack against a Stanley #62. The #62 is a wonderful plane, and it works really well, but it lacks the authority of the LAJ.

Another comparison: use a LN #60 1/2 and LV LA block planes (both in LA format). I own both. I prefer the LN in my hand. Its smaller size offers better "feel" for my hand. But it weighs 600 gms against the 800 gms of the LV, and the LV is the better plane on the shooting board. More authority. I have had the chance to use other block planes the same size as the LN that weigh considerably more, and they too were preferred.

Note that I am not stating that one cannot use a higher angle of attack or a lighter plane. I am saying that the best combination is a low angle of attack along with higher mass.

Regards from Perth

Derek

 

[Philly]

Some good points there, Derek. Look forward to your shooting board article.
And nice work on the Stanley #51/52 - not jealous at all...... :mrgreen:
Best regards
Philly

 

[Digit]

No you don't disagree with me Derek, my heavier plane comment was in reference to smoothing etc. On a shooting board, which I also have a number of, the heavier plane is definitely an advantage I find.
The problem with metal planes on shooting boards is that they can become uncomfortable to use after a time, so I'm looking at a wooden one with handles and loaded with lead? to get the weight and momentum.

Roy.