Chip Breaker Slippage with Krenov Plane

[Mark Ketelsen]

I recently made this smoother using firewood (swamp white oak I think) a lignum vitae sole, a lacewood wedge and a Hock iron/breaker.

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It planes beautifully, producing sub-.001" shavings when adjusted right.

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My problem is that I'm new to adjusting this type of plane and by the time I get it set for a fine shaving, sometimes the chip breaker will have shifted relative to the iron from where I had it set. This happens even with the screw really tight.

With my other planes, I get excellent results on difficult timbers by setting the breaker really close to the edge, but I can't reliably do this given my problem. So If you have had and solved this problem or know why this is happening I'd be most appreciative for your input.

[Jim Koepke]

Without seeing the chip breaker, blade and screw it is difficult to go through a list of possible causes.

It could be the threads on the screw stop short. It could be there is no tension between the blade and breaker when the screw is fully tightened.

The plane does look nice. Is the body laminated? I do not really see any saw lines for the sides.

jtk

[Chris Vandiver]

Short of contacting Hock for advice, you could try putting some texture to the backside of the screw and/or the area around the blade slot. By the way, nice job on the plane!

[David Weaver]

The cap iron is probably sticking on the wedge.

I'd do like chris said. Take the iron and the cap iron and make deep scratches perpendicular to the iron's length with fresh aluminum oxide sandpaper, or something with hard particles like that - something in the 100-220 range.

Just don't do it close to the cutting edge on the iron or the cap iron, do it further up on a noncritical area.

[Steve Voigt]

My problem is that I'm new to adjusting this type of plane and by the time I get it set for a fine shaving, sometimes the chip breaker will have shifted relative to the iron from where I had it set. This happens even with the screw really tight.


Hi Mark,
First off, nice looking plane!
When you first assemble the irons, I assume you tighten the screw with your fingers, taking advantage of that oh-so-convenient knurling. :D :D
Here's the question: Once the assembly is finger tight, how much can you turn the screw with a screwdriver until all the spring is taken out of the chipbreaker? If it is less than a quarter-turn, you may not have enough bend in the chipbreaker. I had one Hock iron that was this way. Carefully increasing the amount of bend solved the problem. But if you already have enough spring in the breaker, it might be one of the things Dave, Jim, or Chris mentioned.

Steve

[Greg Wease]

You might be too heavy-handed when seating the wedge. It needs to be tight enough to prevent the iron from moving backwards when planing but not so tight that your double-iron can't move for adjustments. I did have a problem with one plane that had a lovely cocobolo wedge. It was so slippery that I had to hammer the wedge too tight for easy adjustment. However, I have never had the chip breaker move on a Hock blade after tightening the screw.

[Kees Heiden]

Mine does the same, sometimes. My plan is to rough it up at the upper end, but I haven't got round to it yet.

[David Dalzell]

Have you checked the groove you cut for the cap screw head for both depth and length? i.e. to insure the cap screw is not dragging on the bottom of the groove or reaching the end of the groove. Also check that the cap screw threads do not protrude out of the blade when screwed in tightly. Any protrusion will probably hang up on the wedge holder.