Pint of bass, porkpie, and packet of crisps please
- 7 Jul 2010
- Reaction score
The Stay-set cap iron seems to work well but that has its quirks too. Best is that it doesn't bend the blade and applies the pressure from the lever cap to the edge, the middle and the top under the cam. Three points.Well tibi, you have learnt some valuable lessons on cap-irons, so you haven't wasted your time.
The situation you described is pretty commonplace on old planes. I think Stanley et al deliberately made the cap-irons so that most of the CI sits flat against the blade when screwed together and the curved end puts sufficient pressure on the mating edge. This causes no or minimal flexing of the blade iron. The trouble starts when for various reasons, you need to re-seat the end of the cap iron on the blade. You don't have to remove much to find you're no longer getting firm contact with the blade. This is easily cured by bending the cap-iron just a little - old cap-irons are thin & "soft" steel which is pretty easy to bend. But do it carefully, if you over-bend the curve you can get into a situation where you've shortened the CI & you run out of depth adjustment - it's all very finely calculated and you don't have to alter the edge-to-cam-slot distance by much to get into trouble, as you've discovered.!
I really like the old-style cap-irons, they use a minimum of material but the design allows them to work very well. It's a well thought-out mechanism, I reckon. If everything is fitted properly, the cap-iron & blade should pull together with no or minimal bending of the blade when the retaining screw is tightened, but apply sufficient pressure to close the end securely against the blade. It doesn't need a lot, the lever cap pressure will add a bit more & it should be plenty enough for normal use if everything is right:
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The trend started a few years back to make very heavy replacement cap-irons, the idea being to add more stiffness to the blade/cap-iron assembly. The cap-irons are similar to the ones used with very heavy blades on old planes, they have a single bend to bring the edge to bear against the blade. This it does, for sure, and there is no problem with thick blades, particularly the very thick blades of old, but they don't work so well with the thin Stanley/Record blades, imo. When tightened down, these caps can put a very distinct curve in the blade!
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The lever-cap won't 'straighten' something like this, it only applies pressure at top & bottom of the assembly, leaving all or most of the curve intact. This may or may not matter - depending on the type of wood you plane & how heavily you're cutting, you may not notice anything untoward, but I've found it can certainly promote a tendency to chatter in some situations & I think is best avoided - better to have it so the blade assembly sits nice & flat on the frog.
So when tinkering with cap-irons, there are a few things you need to keep in mind....
It's not just the staying set which is (slightly) useful but also the 3 point solution to all the probs IWW points to above.
Out of many odds and ends I've bought and turned over for years the Stay-set cap irons are the ones which I won't be putting back on ebay!
PS then there is the Millers Falls two part lever cap The Millers Falls Two-part Lever Cap - the small workshop which also has the 3 point idea but differently. No modern versions being made however.