Thread: Cap Iron Deflection Angle.

The Kato and Kawai video was not made to show people how to set a hand plane cap iron. It was research for the super surfacer.

K&K did issue a very brief paper for schools to use to describe setting the cap iron on planes. It was a lot less technical and it more or less said to set the cap iron close enough to straighten the chip. They also mentioned when setting a hand plane that when the cap iron is working, the shaving will be less long than the wood that it is planed from due to compression.

There is no magic number or angle given in their paper (they didn't suggest taking anything from the super surfacer video and applying it to hand planes). I included that video in my original article because I had talked about cap irons for a couple of months before the video came out and nobody believed me that they worked except for the people already using them. There are a few people who used the cap iron before that, and who have come out of the woodwork after the fact. I don't know why they never spoke up before. At any rate, people see the video, they believe the cap iron works, but then errantly assume that it gives end-all definitive settings for a hand plane, and that's not what it was for.

Here's the text from their abstract that has to do with hand planing. It's kind of rough to read - they are setting japanese planes, which are hard to set by eye because you can't see the business end of the iron - it's obscured by the wear of the plane. Western irons are easy to set by eye, so you can ignore #6 unless you're setting japanese planes or some other plane where the iron and cap iron are not attached to each other. The shaving straightens when it shortens, there's no need to measure the length:

The objective of the work was to investigate the influence of capiron angle and cap iron recess on the level/quality/amount of the work on the shaving in double blade planing. The cutting force/resistance and length of shaving .
1. Average double blade resistance(planing force) increased with amount of cap iron effect compared to single blade.
2. In that occasion horizontal force starting from condition when shavings are not touching cap iron, started to show change. In vertical force, from point where shaving started to touch cap iron sufficiently the change startedto show clearly (sharp change).
3. Cutting resistance range showed the tendency to increase in accordancewith cap iron effect.
4. Shaving length is thought to be a favorable factor to determine the effectof cap iron on shaving by observation (looking at it with naked eye).
5. Also length of shaving reacted sensitively to the wear of the blade whichcould not be observed by cutting force.
6. Analyzing the use of hand planes can say:Setting cap iron can not be done by eye. Must take a test shaving and judge work(effect of) of cap iron little by little with precise adjustment. For judging, one of the methods is to measure length of shaving. [I presume that the cap iron is adjusted close, but not so close that a scrunched shaving results.]

One other side comment. I came to like the stanley cap iron profile and its requisite approximate angle because it just works a charm. I tried stock irons in wooden planes and found they work better when the front edge is rounded similar to the stanley - and I have received some old ones that were worked on the front, but never as neatly as I like to work them.

I tried 80 degrees hoping that it would provide a wide range of adjustment, but then found that it didn't - instead, it was extra sensitive. That wouldn't be a problem in a super surfacer, but it's a problem in a hand plane.

I settled on about 50 as giving the best tearout reduction as well as a lot of forgiveness in setting the cap.

And then Kees (or maybe at the same time), tested the same thing and came up with roughly the same conclusion.

It is something that needs to be tested at the bench - in the middle of a project where a lot of planing is done, not in pictures or videos. A project that requires hours of planing is the kind of thing that will really separate what works well and what doesn't (or what just works OK) - we tend to get more picky with things being optimal when we are getting tired.

Originally Posted by D.W.

The Kato and Kawai video was not made to show people how to set a hand plane cap iron. It was research for the super surfacer.

K&K did issue a very brief paper for schools to use to describe setting the cap iron on planes. It was a lot less technical and it more or less said to set the cap iron close enough to straighten the chip. They also mentioned when setting a hand plane that when the cap iron is working, the shaving will be less long than the wood that it is planed from due to compression.

There is no magic number or angle given in their paper (they didn't suggest taking anything from the super surfacer video and applying it to hand planes). I included that video in my original article because I had talked about cap irons for a couple of months before the video came out and nobody believed me that they worked except for the people already using them. There are a few people who used the cap iron before that, and who have come out of the woodwork after the fact. I don't know why they never spoke up before. At any rate, people see the video, they believe the cap iron works, but then errantly assume that it gives end-all definitive settings for a hand plane, and that's not what it was for.

Here's the text from their abstract that has to do with hand planing. It's kind of rough to read - they are setting japanese planes, which are hard to set by eye because you can't see the business end of the iron - it's obscured by the wear of the plane. Western irons are easy to set by eye, so you can ignore #6 unless you're setting japanese planes or some other plane where the iron and cap iron are not attached to each other. The shaving straightens when it shortens, there's no need to measure the length:

The objective of the work was to investigate the influence of capiron angle and cap iron recess on the level/quality/amount of the work on the shaving in double blade planing. The cutting force/resistance and length of shaving .
1. Average double blade resistance(planing force) increased with amount of cap iron effect compared to single blade.
2. In that occasion horizontal force starting from condition when shavings are not touching cap iron, started to show change. In vertical force, from point where shaving started to touch cap iron sufficiently the change startedto show clearly (sharp change).
3. Cutting resistance range showed the tendency to increase in accordancewith cap iron effect.
4. Shaving length is thought to be a favorable factor to determine the effectof cap iron on shaving by observation (looking at it with naked eye).
5. Also length of shaving reacted sensitively to the wear of the blade whichcould not be observed by cutting force.
6. Analyzing the use of hand planes can say:Setting cap iron can not be done by eye. Must take a test shaving and judge work(effect of) of cap iron little by little with precise adjustment. For judging, one of the methods is to measure length of shaving. [I presume that the cap iron is adjusted close, but not so close that a scrunched shaving results.]

Setting a Cap Iron

Signing off gents. There are more important priorities. The lawns need to be cut and some luggage packed. I am heading to Perth tomorrow for 5 days.

Stewie;

No clue what point you're trying to make linking my article. I do tend to like my way better (learn to set it so that it looks good and then set it by eye).

DW, Derick, and others involved with trials on cap irons.... I appreciate the work you guys have done to make some usefulness out of the cap iron. I never really saw it discussed on the forums I frequented (guitar building related)...

The techniques we most commonly used were
1. Maintaining a wickedly sharp edge
2. Planing with the grain as much as practicable.
3. Taking finer shavings until tearout disappears
4. Punt. Use powered abrasive sanders... Works like magic in difficult wood! I love my wide drum sander!

I have tried to set my cap irons "close" to the edge. Generally closer than 1/32". The general admonition was the familiar vague "they need to br set close..."

I have seen straight shavings come out of my planes that were shorter than the work... Never put the connections together that there was something useful and beneficial going on or that it was due to specific settings of the cap iron.

I want to experiment with the cap iron to bring my planes back into more useful service... As your point about wasting hours making transparent shavings when you really want to take off 0.003" or 0.004" without worrying about tearout ruining your day.

So... Thanks Stewie for dredging this topic back up.

It'll be perfect (the cap iron work) for what you're doing. No risk of any significance, no need to constantly sharpen (you'll be tearout free all the way until the plane absolutely refuses to cut). Just plane to the mark with as thick of shavings as you desire or can manage.

Nothing wrong with a big drum sander, though! Friend and I copied a curly maple blanket chest long ago. It was raised panel type with large curly maple panels (long before i could plane competently, and before he had a spiral head planer) - we were afraid to run all of the panels for two of them through his planer and there was no chance we'd plane them. One of his buddies - retired teacher who had made a habit of picking up school shop stuff as the school shop programs get cut around here - has a 52 or 54 inch three drum Beach oscillating sander. We thicknessed ten large panels through it in about 15 minutes for a charge of $20 to each of us. It could take an eighth of an inch off in a pass on panels about 20 inches wide.

If I was making such things for pay, no way I could compete with that productivity with a hand plane.