LN chip breaker and blade flexing: Oops, fixed it

Hello. Recently I bought a LN chip breaker to go into my second #7. The first #7 has a Hock chip breaker in it. The LN chip breaker is slightly curved along its length and when I tighten the screw, it flexes the blade so much that it doesn't sit flush on the frog anymore. It rests only on the very top and botton of the frog. It's not normal, is it? I can understand slight flexing, but with LN chip breaker, it's a lot. This is the first LN chip breaker I'm dealing with, so I wanted to check with SMC folks before getting in touch with the shop I got it from. If you could let me know what you think, I'd appreciate it. Thanks.

Update: I just bent it back with a couple of clamps and it should do it. I was bit surprised with the massive flexing. Sorry :)

Sam, I was going to start a thread. On the fact that I just install a Hock chipbreaker in my Stanley #7. All I can say is WoW! I was able to go from a blade that chattered to .001 chip by just changing the chipbreaker. Makes me wonder if it's more important the blade thickness.

Call or email LN -- my experience is that they are really helpful about any issues.

Thanks guys. I thought about sending it back, but it's a 30 dollar piece of steel, and sending it back alone cost half that much from Japan, so I figured it would save a lot of trouble for me and the shop if I just bend it back myself. I just clamped one side on a steel block, pressed the unsupported side with a clamp, gradually moving up the leverage point until it was nearly flat. It had little twist, so I grabbed the piece with straight chisel and saw handles, twisted it and then it was done. I just never encountered a chip breaker with this much curve, so it was puzzling me if it's supposed to be like that to begin with.

I'm actually pretty happy with Hock chip breaker. The only reason I got LN chip breaker this time was because it looks more traditional :) But yes, thick chip breaker certainly is a great improvement on these bench planes, especially since I use thin blades on my #7s.

I sometimes wonder about which one is more important as well. Personally I think if blade is thick enough, chip breaker is unnecessary (aside from engaging the lateral and depth adjuster), so priority is on the blade. But I have no evidence to prove that, other than from my own opinion about that. It is as ambiguous as "plane seems to work better with thick chip breaker on". But I'm not too worried about details, as long as they work fine for me.

I had a similar problem with an LN blade; so curved that there was a gap between the blade and the chip breaker.

Seems like LN quality control needs some help.

-TH

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Originally Posted by Russ Massery

Sam, I was going to start a thread. On the fact that I just install a Hock chipbreaker in my Stanley #7. All I can say is WoW! I was able to go from a blade that chattered to .001 chip by just changing the chipbreaker. Makes me wonder if it's more important the blade thickness.

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There are a lot of things going on with a chip breaker that can influence the performance of the blade. Most noticeable is having a slight gap catching the dust from the shavings to the point of causing a clog of shavings. This is why some suggest a bevel on the chip breaker so there is just a thin line of contact at the tip of the breaker on the blade. This area should not have nicks or dings on the metal to catch wood particles.

There can be a problem if the chip breaker has too much flex. This can cause the blade to be lifted off of the frog which can cause chattering. Hold a plane up between a light and your eye. Can you see light between the frog and blade?
If yes, the chip breaker may have too much curvature and be stressing the blade.

There are also problems of the chip breaker being the wrong one for a plane. This can make it almost impossible to have the proper adjustment on the blade depth.

The wrong screw on the chip breaker can cause problems of incorrect seating to not tightening properly. This is noticeable when the blade does not move when the adjuster is being adjusted. The chip breaker will move, but the blade will not.

jim

Thanks Jim, you hit on a few of my findings. Especially the part about chips getting caught between the chip breaker and the blade. So I honed the face of chip breaker so it would sit flat against the blade. It helped but didn't solve the chatter problem. Though I feel the Hock chip breaker is a vast improvement over the stock design. I'm still new at hand tools. And Jim your in site and comments are huge help.