Another chip breaker question

[David Wadstrup]

I'm new to bevel down planes, having just received my first 2(a #6 and #4) a few weeks ago. Having read a bit about using the chip breaker to control tearout, I honed both to about 45 degrees and keep them really close to the edge of the iron. I have 2 questions I was hoping you could help me with:

1) I've noticed a tendency for shavings to get caught between the chipbreaker and the iron. Is this a result of setting the chipbreaker too close to the edge of the blade? Or is there some other reason? It does seem to happen less when I set the blade back a little further.

2) I'd like to put a slight camber on the iron in my #4. Is there something special I should do with the chipbreaker? I don't feel comfortable cambering it as I'm afraid of losing too much of the underside surface that mates with the blade(it is a LN chipbreaker.) Or should I just set it as close as the straight edge of the CB will get to the cambered edge of the iron?

Thanks for your help.

[Mark Engel]

I'm no expert, but I will venture an opinion.

If the shavings are getting between the chip breaker and the iron, you probably need to work on the edge of the chip breaker that seats against the back side of the iron. When the chip breaker is installed on the iron you should see no light between the breaker and the iron. The chip breaker should mate with the back side of the cutting iron with no gaps.

For a cambered iron, I set the chip breaker to be just back of the outside edges of the cutting iron. I don't worry about the set back, just get the chip breaker almost touching the left and right edges of the cambered cutting iron.

I don't understand what you said about honing both to 45*. What did you hone to 45*?

[David Wadstrup]

Thanks, Mark.

That's the thing -- the CB mates with the back of the iron perfectly. It couldn't be a tighter fit. This is why I'm so confused. It just doesn't seem possible that shavings are working their way between the 2.

I honed the CBs to 45 degrees. They had come with a much sharper angle -- probably about 25 degrees -- and I read that honing a steeper, secondary bevel would be beneficial.

[Steve Voigt]

Thanks, Mark.

That's the thing -- the CB mates with the back of the iron perfectly. It couldn't be a tighter fit. This is why I'm so confused. It just doesn't seem possible that shavings are working their way between the 2.


There are only 2 possibilities, it seems to me. Either the fit is not as tight as you think, or the screw that clamps the irons together is not applying enough force to resist the wedging force of the chips. I tend to doubt the latter, though. Try assembling the irons so the screw is just barely snug, then look for a gap. Shine a light in from the side, if possible.

[george wilson]

I think you have it,Steve and David.

[David Weaver]

There's either a fit problem or a leading edge problem (e.g., the undercut on the front edge isn't done such that there's a knife edge contact at the very front and relief after that from the undercut).

You don't have to do anything when you have camber. The cut will be light at the edges, and the fact that the cap iron is close to the edge won't matter because of it. You definitely don't want to try to profile the cap iron or anything to follow it, the cap iron should just be left straight across. Even if the iron at the edges of a very cambered iron is under the cap iron completely, it makes no difference since the cap iron doesn't advance past the mouth (any parts of concealed iron will never cut.

[Mark Engel]

Thanks, Mark.

That's the thing -- the CB mates with the back of the iron perfectly. It couldn't be a tighter fit. This is why I'm so confused. It just doesn't seem possible that shavings are working their way between the 2.

I honed the CBs to 45 degrees. They had come with a much sharper angle -- probably about 25 degrees -- and I read that honing a steeper, secondary bevel would be beneficial.

If it couldn't be a tighter fit then the shavings could not get in there. If the shavings are getting in there, than the fit could be tighter. Sorry, that's just my logic kicking in.

[steven c newman]

Most of the chip breakers i re-do I grind a back bevel to it. That way, it will flex just a tad as the screw is tightened down. Almost a knife edge to it.

The two cambered irons I have, I place that knife edged chipbreaker just as close to the corners as I can. Both planes are #5. Never had an issue with chips getting between the two pieces.

[David Wadstrup]

Thanks, everyone.

I just took another look and from what I can tell the point of contact between the iron and CB is tight. I did move the CB back to about 1/64" from the edge of the iron(previously, I had it at around 1/128" or, maybe, even less.) I'll put it to work tomorrow and see if I'm still getting the clogging, and report back.

Thanks, again. I really appreciate everyone's insight.

One last question:

How far does everyone here set the CB edge from the iron's edge?

[David Weaver]

Probably in the neighborhood of a hundredth of an inch or so. 1/128th is a decent number - for a smoother.

Farther off than that for planes that make a heavier cut and have a lot of camber if you measure from the point at the longest point on the iron.

[Jim Koepke]

It is possible to have a tight fit yet still not have full contact across the front edge of the chip breaker.

This is one reason for having the mating edge of the chip breaker being beveled so just a thin piece of metal is making first contact.

Here is a post on chip breaker fettling:

http://www.sawmillcreek.org/showthread.php?114373-Fettling-A-Plane-from-Junker-to-Jointer&p=1158886#post1158886

I tend to smooth the front of the chip breaker so there is no place for a shaving to catch.

If shavings are getting caught, there is something catching them.

jtk

[bridger berdel]

really close chip breakers are for really fine shavings. for thicker shavings, move the chip breaker back. for really thick shavings, the chip breaker isn't really doing anything. scrub planes don't need one at all.

[Jim R Edwards]

I don't own many bevel down planes (I prefer bevel up) but, I never measure the distance. I would guess mine are 1/16th from the edge of the blade. Never had any issues with tear out. Have you tried setting the breaker back a little? If so did it work?

[David Wadstrup]

Well, I was able to spend a bit of time with both these planes today, and had none of the clogging issues I had earlier. Can't really explain why, other than I had the CB set too close to the edge of the iron. Who knows, maybe I had it so close before that it actually extended *beyond* the edge of the iron. Anyways, thanks for all of your help. I'm glad this problem is now behind me.

PS It really has been a fun experience using BD planes for the first time. They feel totally different. Not better or worse, just different. At first I was reluctant to embrace the mechanism for advancing the blade. Didn't like it as much as LVs BU adjusters. Slop in the wheel, etc. Now, however, I've found that I do like being able to have a finger on the wheel for quick adjustments whenever they're needed.

[David Weaver]

The backlash bother sort of goes away, as does the mental block with slop in the lateral adjustment. I doubt it's ever really more than a second for me to get the backlash out of the depth adjustment, and half the time you adjust (or more), you're making adjustments in the direction that tension is already on it.

The difference in feel with the cap iron is one of engagement. The plane feels more engaged in the work, and less loose feeling in a heavy cut. Cuts that chattered before won't do it, and cuts that tore out before won't do it. It's really satisfying to get that with a "cheap" tool.