Record No.8 Blade

[Martin Cash]

There are at least two considerations in fitting a super thick blade to a handplane.
The first is the obvious one of whether the blade will physically project into the mouth of the plane. Better if you don't have to file the mouth opening bigger IMHO.
The second is the fact that the depth adjusting lever end has to project through the blade to reach the cap iron/chip breaker.
With a very thick blade it simply cannot reach it and you lose any depth control.
If you buy a replacement blade from LN look for the one that is specific to your model.
Often the blade that came with the plane is perfectly adequate when it is fettled correctly.
Might just need some TLC.
Regards
MC

 

[IanW]

Something to be aware of when fitting thicker blades to a Bailey frog. The 'spigot' on the adjustor cam has to reach though the blade to engage the slots on the cap iron. There is not a lot of extra length on the spigot, and with many planes that I've handled, you get very little purchase on the cap iron slot with a thicker blade - if the LN blade is 'extra thick' it may not reach at all! 'Spose you can always adjust with a mallet. :wink:

Personally, I think the current passion for thicker and thicker blades is a bit of a fad. You can make a standard blade work pretty well if you pay attention to the details, as someone has already mentioned. A thicker blade of better quality steel may then be a good investment, but a thick blade poorly seated, on a poorly-seated frog (read any of the blue or black thingies manufactured after the mid sixties or so) will give just as poor results as the original.

I've had debates on other forums about this. I have a theory, (backed up by (VERY) limited empirical evidence ), that you get some advantage by putting thicker blades in standard Bailey frogs up to about 3.5mm thick, using the original cap-irons - after that, the law of diminishing returns cuts in rather savagely. To my mind, the geometry starts to go awry. The thicker the cutter, the longer the bevel for any given grind angle. For a blade 5 or 6mm thick, the point at which the back finally sits on any plane metal starts to get a long way aft of the cutting point. Granted, this cantilevering of the cutting edge is offset somewhat by the thicker blade, probably by the greater mass lowering resonant frequency & thus less tendency to chatter. But somewhere, there must be a point at which things start to go the other way. The brilliance of the cap-iron is that it solves much of the chatter problem by pre-tensioning the cutting end when properly fitted, plus adding mass. You can often get a very satisfying improvement in the cut & feel of a Bailey plane simply by adding a heavier and well- fitted cap iron, given the cutter is of reasonable quality. (They are not hard to make, in fact).


That ought to attract some strong responses from the 'thicker the better' clan. :wink:

Cheers,
IW

 

[bugbear]

That ought to attract some strong responses from the 'thicker the better' clan. :wink:

Steve Knight found some research (I'll try to dig up a reference) to the effect that "thicker the better" only holds up to 3/16".

This (coincidence... ?) is the normal thickness of the working ends of blades in old wooden planes.

BugBear

 

[IanW]

[Steve Knight found some research (I'll try to dig up a reference) to the effect that "thicker the better" only holds up to 3/16".
BugBear

3/16" = 4.76mm, which is a bit more than the 1/8" or 3.5mm I suggested, but not far off, and supports my theory. Would like to see anything that really investigates this aspect if you can dig it up, Bugbear.

This (coincidence... ?) is the normal thickness of the working ends of blades in old wooden planes.
BugBear

Your implication is that it is NOT a co-incidence, & I'm inclined to agree - there were a few hundred years of experience behind the last of the woodies..........

Cheers,
IanW

 

[Digit]

That ought to attract some strong responses from the 'thicker the better' clan.

I know a chap who does a nice line in tin helmets Ian! :lol:
I fit old woody blades to Stanleys, and without mods adjustment can be lost due to their thickness. There seems to be one aspect of better irons that isn't mentioned, I fit old woody irons simply because they seem to take, and hold, a better edge.

Roy.

 

[Paul Chapman]

Something to be aware of when fitting thicker blades to a Bailey frog. The 'spigot' on the adjustor cam has to reach though the blade to engage the slots on the cap iron. There is not a lot of extra length on the spigot, and with many planes that I've handled, you get very little purchase on the cap iron slot with a thicker blade - if the LN blade is 'extra thick' it may not reach at all!

You can always lengthen the Y lever

Cheers :wink:

Paul

 

[ivan]

Thicker irons work (look at a Japanese plane) because the stiffness of the blade is proportional to the cube of the thickness. A blade twice as thick has a bevel of double the length, but is 8x stiffer (2x2x2). Twice the bending moment from the longer bevel, but 8x stiffer, so deflects 1/4 less.

A 2 piece cap iron can improve clamping still further, although most lever caps are a bit too long. The iron is then clamped in 3 places rather than 2. Also one piece cap irons bend the blade off the frog so most of it is actually floating free (made for chatter). A standard blade vibrates as it cuts, viewable on a dial gauge. The original Record 2 piece had a front section parallel to the blade so tension remained constant whilst adjusting. Current 2 pieces are not so well made and need tweaking.


The standard LN No 8 blade is almost 5mm thick and can be fitted to a Record, but you'll need a LN capscrew and have to modify cap iron or Y lever. Probably only worth the effort for planes intended for final finsh.

 

[Digit]

Most irons from old woodies are pitted with rust, but I have one fitted to a No 4 that is clean enough to show that the cutting edge is a piece of steel that has been hot welded to a length of mild steel/wrought iron.
The stresses from the welding have caused the cutting iron to bend so that it does not actually touch the frog.
This leads me to believe that Bedrock frogs etc are simply an attempt to make a whippy piece of metal perform as a thicker, less flexible, piece would.
Wooden planes with a wedge can be a pain to set, but their support of the iron is superb, far superior to a Bailey type.

Roy.

 

[ivan]

Any iron screwed to a bent one piece cap iron, will itself bend as the screw is done up. A standard Stanley blade/cap iron screwed together will be somwhere around 20 thou away from straight. Clamping it to any style frog with a lever cap will not remove the bend. Only the top of the blade and the heel of the bevel contact the frog. You can see light under a LN blade/frog too, although not quite as much. If your wooden plane blade/cap is of similar design (however meaty) it too will not be straight. I don't know if the wedge when driven in, will force the blade down on the frog or not (I've no experience of wooden planes)

Trouble is, cutting forces on the tip of the blade are trying to lift the blade away from the frog, (which it is not actually touching, and where it is not actually clamped). It's trying to pivot about the heel of the bevel. If you put a 6" steel rule at right angles to a table edge, with 1/2" sticking over the edge to represent the bevel, and try to clamp it flat with a fingertip right on the table edge and another at the 4" mark, you'll see how easily the blade lifts up around the 2" mark, if you give the rule a prod on the end to simulate a cutting load.

The main benefit of the bedrock (seems to me) is the ability to adjust the frog without removing the blade, and without umpteen attempts to get the frog square after you've moved it. If you use a thick blade, around 5mm, I'm not sure it has any actual cutting advantage, apart perhaps from a bit more weight.

The 2 piece cap iron like the Clifton does not bend the blade when fixed to it. The loose piece at the sharp end divides the pressure from the levercap's tip into two, so the blade is clamped to the frog (cf steel rule above) at the "1/2" , "2", and "4 inch" positions. The loose piece should be parallel to the blade, and the levercap close to its middle or the double calmping will not be very effective. It's an unfortunate fact of life that the manufacturers often don't understand well, what they are making.

 

[Paul Chapman]

The main benefit of the bedrock (seems to me) is the ability to adjust the frog without removing the blade, and without umpteen attempts to get the frog square after you've moved it. If you use a thick blade, around 5mm, I'm not sure it has any actual cutting advantage, apart perhaps from a bit more weight.

I think it's true to say that the Bedrock frogs being made today by Clifton and Lie Nielsen are far more accurately machined than the Bailey frogs fitted to most planes and this, in my view, helps as it means that the blade and cap iron asssembly seats better on the frog.

Cheers :wink:

Paul

 

[IanW]

Ivan - what you say makes perfect sense, and you have explained the only sensible reason for having a two-piece cap iron. The 'stay-set' claim was always nonsense, given the slop in the system - you could never replace the blade accurately enough to start planing again without re-adjusting!)

But for a single-piece cap iron that is properly designed, the upper part should sit flush on the cutter when the screw is tightened. After tightening the screw, the (rounded) end should touch the back of the cutter firmly and neatly, but there shouldn't be any significant tendency to bend the cutter in the middle. All but a tiny component of the tensioning force at the cutting end should come from the lever cap being locked down. If the line of contact of the lever cap is not as close as possible to above the last point of contact of cutter & frog, that would tend to bend a thin blade/cap iron assembly. Poorly-designed (e.g. some of the ones you see with just a single sharp bend at the end) or badly- fitted cap irons will certainly put a curve in thin blades - something else a thicker blade resists, so that it seats a bit better.

It's taken me a heck of a long time to figure out how to make all my Bailey types work well. It's such a simple-looking device, but there are a few hidden traps. Having a really good old #5 that worked well to start with, was my saving - I was slowly able to figure out why the others didn't do so well by comparing, plus reading various articles helped a lot. However, there are quite a few inaccuracies perpetrated - the nonsense about the cap iron being a "chip-breaker" is a particular peeve of mine.

And I think you're dead right about manufacturers not having a clue about how their planes actually work. The two piece cap iron on a new plane I bought a while back (brand name withheld but you can probably guess!) was a mess. The removeable bit was so badly fitted you had to slew the capiron way off to get the end parallel. Rather than muck about with it, I gave it away and made a new single-piece capiron - at least it sits straight, works just as well, and I'm not panicking about losing the end bit in the shavings every time I sharpen... :wink:

Cheers,
IW

 

[Philly]

However, there are quite a few inaccuracies perpetrated - the nonsense about the cap iron being a "chip-breaker" is a particular peeve of mine.

Amen, Brother!
Philly

 

[Digit]

Manufactures knowing about their products?
I think it was Jim Kingshot who complained to Record/Stanley about the coarse finish on the base of their modern productions and was informed that 'carpenters prefer them rough so that they can rub them over with candle wax.'

Roy.

 

[bugbear]

The main benefit of the bedrock (seems to me) is the ability to adjust the frog without removing the blade, and without umpteen attempts to get the frog square after you've moved it. If you use a thick blade, around 5mm, I'm not sure it has any actual cutting advantage, apart perhaps from a bit more weight.

I think it's true to say that the Bedrock frogs being made today by Clifton and Lie Nielsen are far more accurately machined than the Bailey frogs fitted to most planes and this, in my view, helps as it means that the blade and cap iron asssembly seats better on the frog.

Cheers :wink:

Paul

Heh. Long ago on Badger Pond someone posted pictures of a blade assembly on a frog, outside the blade. Since the blade is actually BENT (slightly) by the cap-iron, the blade is slightly concave, so so only touches the frog at two points.

The lever cap then mashes the whole thing down, removing some of the bend.

But the blade is at least touching firmly at the heel of the bevel.

The notion of "full contact" flat-on-flat bedding is more in our heads than in our planes.

BugBear

 

[Paul Chapman]

Since the blade is actually BENT (slightly) by the cap-iron

Which is why I use the Stay-set cap irons - they don't bend the blade :wink:

Cheers :wink:

Paul

 

[ivan]

It's true a better designed one piece cap iron like the LN does not bend the iron so much as the standard type. However, the sharp end of the cap iron must press down on the blade as the screw is tightened up, or it won't keep the shavings out. Ergo, the blade gets bent, in the LN case, a thou or two, enough to let light between blade and frog, which according to tradition "is supporting the blade". Of course, as cutting tends to lift the blade, the whole idea of support is a nonsense (apart from a narrow strip at the heel of the bevel). The lever cap/one piece cap iron combination definitely cannot clamp the blade flat to the frog, even on a LN. Try taking off the frog and fitting the blade back, and see the slip of light for yourself, or, better, check the contact with a bit of marking blue. Nor does the levercap assist in any meaningful way to stop the blade lifting under cutting load unless there is a 2 pice cap iron fitted. It can't still be patented, what a pity someone doesn't make a 2 piece with LN quality!

From his design approach, it seems very unlikely that Mr Bailey was much of a cabinetmaker....

 

[bugbear]

From his design approach, it seems very unlikely that Mr Bailey was much of a cabinetmaker....

Ooh, I wouldn't go that far. The bedding-sides of most wooden-plane blades are nicely concave and uneven, so the famous good bedding of this design is hogwash, at least in terms of two mating flat surfaces.

And yet (in practice) the "bedding" is these planes is known to function excellently.

BugBear

 

[Anonymous]

The notion of "full contact" flat-on-flat bedding is more in our heads than in our planes.

BugBear

Don't agree that this is true for all planes. I have looked at the blades in my LNs and LVs and they are not bent one bit. Dead flat against the (very accurately machined) frog. I certainly cannot see any bend, even with a magnifier

Older planes with very thin blades and less than flat frogs might well be very different of course, but then I don't use old planes with thin blades and..........

 

[ivan]

Tony, you must have bought your LNs early, well before the quality dropped off :shock: I have 3 LN bench planes bought in last 2 yrs and there is some daylight visible under the mounted, leverclamped blade on all 3; thus they now have 2 piece cap irons. The standard LN setup is functionally similar to the Bailey, and not designed to lock the blade down to the frog and so prevent it flexing.

 

[Racers]

Hi,

Getting back to the orignal question I see Ray Illes had 2 5/8 baldes for £25 in o1 steel should by nice.


Pete