chipbreakers

11/20/04, 10:35 AM #1

Tony Z.
Guest

chipbreakers

Tony Z.

>First item for discussion: What is the purpose of a chipbreaker (Bailey style): 1. Is it to offer support along the blade, like the Clifton 2 piece model? or, 2. To stiffen the cutting edge, more like the original Bailey and later L-N/Hock offerings?

Second related item: What brought me to the post is a #4 with a Hock iron and a L-N chipbreaker that no matter how much fettling, remained miserable! In all fairness, I must add that I don't believe the chipbreaker was intended for Bailey plane, because I had to alter the location of the yoke engagement slot (brazed in and ground new metal). Regardless, other than polishing of the bearing edge, it was stock.

Late last night I got an idea that maybe the chipbreaker was bearing in an area not intended. So a bit ago, I went down to my shop, and cut a piece of an index card and placed as a shim above the knurled screw that holds the chipbreaker to the blade. Guess what? instant .0015 shavings on QS whiteoak without really doing anything else! Further, I played with a piece of poplar, same thing.

I've found something that seems to work with this plane. Has anyone else had similar experience or tried a similar cure. I believe Garret Hack suggested a "bending" of stock Bailey chipbreakers to gain proper edge bearing, but if this works then the assumption would be that a thick chipbreaker is not really needed.

Tony Z.

Re: chipbreakers

11/20/04, 11:40 AM #2

Tony Z.
Guest

Re: chipbreakers

Tony Z.

>I forgot to add, that after altering the yoke engagement slot, I did surface grind the bearing side of the chipbreaker to assure that any warpage was removed.

Re: chipbreakers

11/20/04, 11:52 AM #3

Moses Yoder in White Pigeon, MI
Guest

Re: chipbreakers

Moses Yoder in White Pigeon, MI

>The cap iron serves several purposes. I think it's most important purpose in a Bailey style plane is to provide a place for the adjuster to catch that remains at the same spot even as the iron becomes shorter from use. Other functions are to curve the shaving forwards as it is cut to reduce tearout; the faster the chip "breaks", the less tearout due to leverage of the chip. And in theory also stiffens a blade, making it less likely to chatter, although I am not really educated on the physics of this theory.

You say that the plane was "miserable" which is not really descriptive of what the problem was, and without knowing more about the results you were getting it would be hard to figure out what the problem is. It seems to me that if you added a shim at the top of the cap iron and the plane started working fine, there is a possiblity that the hole for the adjuster is not quite right and shimming the cap iron up slightly put the hole in a place where the plane is now adjusting correctly. The other possibility is that you could get the same results simply by bending the cap iron slightly, if it is not putting pressure on the leading edge of the iron.

Re: chipbreakers

11/20/04, 8:43 PM #4

Dan Donaldson
Member
Offline
5,264 posts

Registered: 9/17/01

I think that was your problem

Dan Donaldson

>If you surface ground the back side of the chipbreaker, I think that might be the problem. As it comes, the back is not quite flat so that when you tighten it down, the end bears down on the blade. If you ground the whole thing flat, then it was not working as it was originally intended.

- - -

I have been woodworking for about 25 years now, and would consider myself an enthusiastic amateur. My claim to fame (or infamy) has always been fixing stuff. I spent time in the Air Force in the 60's then went to work as an electronic technician for civil service. I finally got my EE, and being fed up with the civil service nonsense, took a job with Ford Motor Company until I went with the split to Visteon last year. I got interested in music and started playing in a bluegrass band. I wanted a new guitar, and that kind of led me into woodworking. I bought some books, a few tools, and built a guitar. Luckily, I didn't know any better than to try that as a first ever project. I still play it when I get a chance, so it must not be too bad if it can live for over 20 years. After a stint in Mexico for my job, I moved into a new house and built a small shop. Since then I have been collecting tools and skills, probably more of the former than the latter ;-). Finding this site has done more for my skills and enjoyment than anything else. I have learned a lot and really enjoy the friendships that I have made here. I have been married to LOML (Lori) for 32 years now and have 6 kids. When they are all gone, I want to get a 1 bedroom house (so there is not room for them to move back in) and at least a 6 car heated/air conditioned garage for a shop. (Dream on...)

Re: chipbreakers

11/21/04, 3:04 AM #5

Dale Stansbery
Member
Offline
714 posts

Registered: 2/7/03

Re: I think that was your problem

Dale Stansbery

>I think Dan nailed it. Every (at least the ones I have actually checked) chip breaker only touches at the leading and trailing edge with the blade. There is an ever so small gap between the blade and chip breaker. When the screw is tightened, the chip breaker flexes and probably the blade too for that matter, and the gap closes. The combination is then under tension keeping the the two tightly coupled at the leading edge. The paper placed above the screw opened that gap. If possible, I think you need to add a little bend to the front of the chip breaker to raise the middle slightly off the blade. If that's not possible, then continue to use the paper shim.

chipbreakers

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