Closely Set Cap Iron

[custard]

I keep finding new applications (or at least new to me) where a closely set cap iron is a real improvement on what I've used before.

I don't make a huge number of boxes, but this year I've had orders for quite a few. Cleaning up the edges to give a perfect fit after separating the lid from the body is often quite time consuming, here's the lid being sawn off, which no matter how much care you take inevitably leaves a fairly rough and uneven surface,

Previously, to flatten off the sawn surfaces I've used a large piece of 25mm MDF with wide belt sander paper veneered to each side, 80 grit on one side and 180 grit on the other,

This time I tried planing off the majority of the waste using a No 4 with a closely set cap iron to deal with the wild grain of the Birds Eye Maple. This happens to be a LN plane, but I've no doubt that a regular Record or Stanley would give exactly the same result. If I did this more often I might think about getting a No 3 plane.

You can see the typically crinkly shaving that you often get with a really closely set cap iron,

It's an entertaining challenge to see if you can go all the way around and produce a single unbroken shaving! Zero tear out by the way, grain direction becomes virtually irrelevant.

With a bit of care you can plane your way to an absolutely flat and gap free fit between the lid and the base in less than half the time that it would take by sanding, and it's certainly a lot more fun!

 

[ac445ab]

Well done! Also a dust free job.

I keep finding new applications (or at least new to me) where a closely set cap iron is a real improvement on what I've used before.

What do you mean with "closely set cap iron"? How do you fix the right distance of cap iron from cutting edge, in a reproducible manner?
I remember the Corneel's demonstration about this argument, some time ago. If I am not wrong, the right distance of cap iron front from cutting edge should be not more than 0,1-0,2 mm for having a cap iron functioning as a chipbreaker in reducing tearout.
Was your setting simple to find?

Ciao
Giuliano

 

[undergroundhunter]

IIRC Chris Schwarz blogged about using a sheet of paper to set the cap iron. He claimed this gave him repeatable results.

Matt

 

[Phil Pascoe]

I read in one of the WW mags. the better part of thirty years ago in an article on fettling planes something that I've only ever read the once (iirc , I'm getting older) a tip that works well if you wish to set your cap iron very closely, and that is to relieve the front edge of the mouth casting - it allows a little more room for the shaving to exit without choking.
You could do some of the work with a dremel but I didn't have one when I first worked on a plane, so I just used a thin file to start (you can't get the angle with a thicker file) until there is room for a heavier file. Stop before you reach the bottom - you're not aiming to alter the shape of the mouth, just the inside of the casting.

 

[ac445ab]

IIRC Chris Schwarz blogged about using a sheet of paper to set the cap iron. He claimed this gave him repeatable results.

Matt

Brillant idea


Giuliano

 

[D_W]

Toss aside the jigs and things like that. Use your plane and set the cap first as close as you can set it and still see a reflection of the blade back (it'll be a tiny hair thin sliver). Then plane with it. If the shaving wrinkles, then take the plane apart and set it a little bit wider, just a hair. Perhaps partially tighten the cap iron and tap the screw with a small hammer.

Within a very short time, you'll just know what looks right, and you'll set it right every time by eye (and "right" will be dependent on what you're doing). It becomes a very trivial thing, like a reflex that you don't have to stop and think any further than when you look at something to see if it appears square or plumb.

If you have a modern cap iron and plane iron that are the same sheen, especially if the cap iron has a flat bevel on it, then just color the front of the cap iron with a black marker. I have a lee valley custom plane that I couldn't see the gap on very well until I did that. Now it's easy, all I need is light from the right direction to see the exposed back of the iron ahead of the cap iron.

Jigging up or measuring is going to end up being very counterproductive in the very short term and especially the long term.

 

[D_W]

I keep finding new applications (or at least new to me) where a closely set cap iron is a real improvement on what I've used before.

I don't make a huge number of boxes, but this year I've had orders for quite a few. Cleaning up the edges to give a perfect fit after separating the lid from the body is often quite time consuming, here's the lid being sawn off, which no matter how much care you take inevitably leaves a fairly rough and uneven surface,



Previously, to flatten off the sawn surfaces I've used a large piece of 25mm MDF with wide belt sander paper veneered to each side, 80 grit on one side and 180 grit on the other,



This time I tried planing off the majority of the waste using a No 4 with a closely set cap iron to deal with the wild grain of the Birds Eye Maple. This happens to be a LN plane, but I've no doubt that a regular Record or Stanley would give exactly the same result. If I did this more often I might think about getting a No 3 plane.



You can see the typically crinkly shaving that you often get with a really closely set cap iron,



It's an entertaining challenge to see if you can go all the way around and produce a single unbroken shaving! Zero tear out by the way, grain direction becomes virtually irrelevant.



With a bit of care you can plane your way to an absolutely flat and gap free fit between the lid and the base in less than half the time that it would take by sanding, and it's certainly a lot more fun!

Love it, Custard. It is probably the most useful thing I've learned with hand tools. Good for both fine work and coarse.

 

[nabs]

I find that if you screw the cap-iron and blade together with the normal amount of tension it is easy to make any final adjustment by tapping the cap-iron screw with the shaft of a screwdriver.

My cap-iron experiments are limited to tool-fiddling tests on bits of cheap construction grade pine - I was interested in the way the wood shavings change as the cap-iron gets closer to the edge, going from tight curls> wavy ribbon (tear-out starts to go away)> straight > crinkled (much harder to push) > stops working.

Do other timbers do the same?

 

[D_W]

Do other timbers do the same?

yes.........

 

[ac445ab]

Toss aside the jigs and things like that. Use your plane and set the cap first as close as you can set it and still see a reflection of the blade back (it'll be a tiny hair thin sliver). Then plane with it. If the shaving wrinkles, then take the plane apart and set it a little bit wider, just a hair. Perhaps partially tighten the cap iron and tap the screw with a small hammer.

IIRC Chris Schwarz blogged about using a sheet of paper to set the cap iron. He claimed this gave him repeatable results.

Matt

Thanks, I'll try in both manners, although I believe the "by eye" method is more subject to make mistakes in finding the exact measure and provide worse performances.

Giuliano

 

[Derek Cohen (Perth Oz)]

Some say that their ideal distance is 0.1 - 0.2mm from the edge of the blade. I tend to look for about 0.3 - 0.4mm. In any event, there is no "perfect" distance - it depends on the wood type and the depth of cut. I set this by eye, not a jig of sorts.

One measure of how well the chipbreaker is set is the shape of the shaving. When the chipbreaker is set too far back to be active, the shaving is curly. When the chipbreaker is set too close, the shaving crinkles like an accordian. One of the pictures that Custard posted looks like this. Too close, and the shaving becomes very accordian-like. This will be usually be together with a rougher wood surface. The ideal shape is a straight, stiff shaving. When the shaving is thicker, it will shoot out of the plane like a stick. I find that even thin shavings, such as when completing a final smoothing pass, still retain this straightness.

Here is a LN #4 1/2 making a final pass. Look at the shavings in the pile to the left ..

Regards from Perth

Derek

 

[swagman]

Derek; If a closely set double iron at common pitch excels at controlling tear-out, why is LN and LV offering interchangeable frogs at 50 and 55 degree beds.

Stewie;

 

[Derek Cohen (Perth Oz)]

Derek; If a closely set double iron at common pitch excels at controlling tear-out, why is LN and LV offering interchangeable frogs at 50 and 55 degree beds.

Stewie;

Stewie, there are two essential reasons:

Firstly, the chipbreaker has been around a long time, but for most on the internet forums the chipbreaker was considered only important to stiffen/support a blade, and not a means to control tearout (it is not possible to speak about those outside the forums). Around 2012, discussion on the WoodCentral and WoodNet forums (strongly lead by David Weaver -DW- while Kees - Corneel here - made a few excellent videos to demonstrate the method) began the push to understand the technique and, eventually, more and more began to discover it and use it to good effect.

LN are still stuck in the pre-2012 era, and assert that the chipbreaker is simply a means of supporting the blade. They support a different method, which involves increasing the cutting angle. They do this via BU planes and, in the area of BD planes, they do this by offering frogs with higher bed angles.

I will add here that Lee Valley began the design of their Veritas Custom planes as a pure BD single iron design around 2012. It was still like this when I visited their factory and trialled the prototype. To the credit of LV, they recognised the importance of the chipbreaker, and re-designed the Custom plane to accommodate a double iron. The frog on my #7 is 40 degrees while that on my #4 is 42 degrees.

The problem I experience with my West Australian woods is that the cutting angle of the steepest bed offered by LN (55 degrees) is still too low to control tearout (when used sans close set chipbreaker). These woods need at least 60 degrees. But even if LN did offer a 60 degree frog, it would not be practical in a wider plane, such as a #4 1/2, since the wide blade would require an impossible amount of effort to push (planes with a low centre of effort, such as BU planes, do not respond in the same way here as the high centre of effort Bailey design). Waxing the sole is just a temporary fix. Adding a high backbevel is similar to using a high angle frog. The only way to deal with the resulting high resistance is to take thin shavings. This is not always practical. Hence my #4 1/2 lay on the shelf for several years.

The second reason why LN offer the high frogs is that there is a demand for it. It has been long recognised that a high cutting angle will control tearout. Further, the chipbreaker is not an easy technique to master. Setting it so close to the edge is fiddly, and very frustrating at the start of the learning curve. It takes someone with determination and an adventuring spirit to persevere and master it. It is just so much easier to use a high angle frog.

Regards from Perth

Derek

 

[swagman]

LN are still stuck in the pre-2012 era, and assert that the chipbreaker is simply a means of supporting the blade. They support a different method, which involves increasing the cutting angle. They do this via BU planes and, in the area of BD planes, they do this by offering frogs with higher bed angles.

Derek; if LN is still stuck in the pre-2012 era, why does LV make the following claim on their web site, a cap iron serves to stiffen a plane blade, helping to damp vibration and reduce the potential for blade chatter. http://www.leevalley.com/en/wood/page.a ... 82&p=66868

 

[Derek Cohen (Perth Oz)]

Derek; if LN is still stuck in the pre-2012 era, why does LV make the following claim on their web site, a cap iron serves to stiffen a plane blade, helping to damp vibration and reduce the potential for blade chatter. http://www.leevalley.com/en/wood/page.a ... 82&p=66868

Stewie, that advert for LV chipbreakers is very old. Probably they could update it. Obviously it is not an issue since it is not about how planes are used, and Lee Valley would not state that chipbreakers are only for damping vibration, as LN will.

Are you sure these posts of yours are really about chipbreakers? :roll:

Regards from Perth

Derek

 

[swagman]

Derek; last question. If the previous description by LV, on the role of the Cap Iron is old and out of date, would you care to explain this one by LV on their new and improved 1/8 inch thick A2 Cap Irons.

Available separately or paired with the bench plane blades, our 1/8" thick A2 steel cap irons serve to stiffen the blade, helping to dampen vibration and reduce the potential for blade chatter. The cap edge of the iron is machined with a relief angle to ensure it always contacts the face of the blade, so no gap can form.

http://www.leevalley.com/us/Wood/page.a ... 43698&ap=1

 

[Derek Cohen (Perth Oz)]

Stewie, I will be polite and answer your question, but you and I (and probably everyone else here) knows that you are fishing ... Please keep in mind that I am not the spokesperson for Lee Valley.

To repeat an earlier comment, the Veritas Custom planes provide an option for use either with- or without the chipbreaker. Unlike the Bailey designs, the Custom planes do not require a chipbreaker to link to the adjuster. The chipbreaker is not provided to stiffen the blade alone. It can that as well. The Veritas chipbreaker is very capable of closing down to control tearout. I know this from personal experience, as well as from discussions with the Lee Valley director of design. Clearly their copy ad could do with a re-write.

Derek

 

[swagman]

Thanks Derek.

 

[D_W]

Derek; last question. If the previous description by LV, on the role of the Cap Iron is old and out of date, would you care to explain this one by LV on their new and improved 1/8 inch thick A2 Cap Irons.

Available separately or paired with the bench plane blades, our 1/8" thick A2 steel cap irons serve to stiffen the blade, helping to dampen vibration and reduce the potential for blade chatter. The cap edge of the iron is machined with a relief angle to ensure it always contacts the face of the blade, so no gap can form.

http://www.leevalley.com/us/Wood/page.a ... 43698&ap=1

Aside from the fact that it does actually provide stability to an iron.

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They leave that there to trigger trolls.

 

[Sgian Dubh]

This time I tried planing off the majority of the waste using a No 4 with a closely set cap iron to deal with the wild grain of the Birds Eye Maple.

With a bit of care you can plane your way to an absolutely flat and gap free fit between the lid and the base ...

You maybe already know this, but the technique you demonstrated is spanning, or at least that's the name I was taught. For what you're doing there I'd probably use a No 5 plane. A longer plane 'spans' around the corners more effectively in my experience.

I've never heard of using paper to set the cap iron close, so I don't know that methodology. But another method is to loosely assemble the cap iron and iron, jam the cutting edge of the iron into the spring growth of something reasonably soft like a piece of redwood, slide the cap iron down to touch the wood and tighten the screw. It takes a bit of practice, but does work. And, of course, there are alternative methods as others have described. Slainte.