Rough finish round knots when planing? Avoidable?

[julianf]

Thank you -

All the points you raise are fine. At present, ive put the old cap iron on the new blade, and the blade will back off fine.

Ill get the calipers out and take some measurement of the old iron and the new, and see what's what. They must be different. If theyre the same, ill be proper confused!

 

[El Barto]

A lot of newer irons are thicker than the older stock irons so it could be that the edge is hitting the mouth. I have a couple of Ray Iles irons that are about a mm thicker than the irons they replaced and that meant that I had to file the mouth slightly wider.

 

[ED65]

I can not work out how to back off the new blade enough. The knob is at full travel, and i cant see that moving the frog would make any difference. Im kind of confused as to what could be wrong?

Thickness of the iron is irrelevant to this, not all cap irons work with all planes.

It's quite common to pick up an old plane where the irons can't be retracted fully, or can't be made to project enough, and the reason is the cap iron is from another maker, or from a different era, and its slot is in a different position.

It only needs a small discrepancy in the position of the slot that the Y-shaped yoke engages with for this to be a problem, for a given setting of the cap iron in relation to the cutting edge. If need be the slot can be modified, and a minor tweak of the Y-yoke can be done sometimes as well.

...have the cap iron set about as close to the end of the blade (1mm or so) as seems sensible?

Depends on what you're doing. It can be set much, much closer than that if needed (see page two).

 

[julianf]

Distance from front of cap iron to slot -

old iron - 95.2mm
new iron - 99.2mm

 

[nabs]

I will be interested to hear if it is possible to adjust the slot/lever to allow for a difference of several mm. At least you can use the old cap iron and new blade if all else fails.

It is odd that cap irons are not a standard size - does any one know if you can swap e.g Record and Stanley cap irons without issue?

 

[julianf]

Well, this one is a stanley iron on a stanley plane... So if that does not match, i guess who knows with the rest?

Im wondering if the frog and / or parts of the mechanism may not be "stock" on my plane, hence the oddity - ill take another look tomorrow.

 

[El Barto]

Did you try using the old cap iron with the new plane iron? That will at least tell if you the problem is the new cap iron. And likewise with the new cap iron and old plane iron. Process of elimination etc

 

[ED65]

4mm difference, ouch! It's still possible to compensate for this but I think that's a bigger discrepancy than most face when this crops up. IIRC most I've had to deal with was approximately 2mm.

So what you need obviously is for the slot to move towards the edge. Taking off some metal from the leading edge can actually be easier than trying to do it all at the slot, but if need be you can do it all at the slot.

A full 4 mils probably doesn't need to go, 2.5-3mm might prove sufficient but that's still quite a bit of filing.