Thread: Gap between cap iron and blade

Flat cap iron is unusual, what brand is it?

To echo TM, very odd!!
Is it an original cap-iron, or has someone tried to make one & failed to grasp what the CI is all about?

As you've discovered, the cap-iron has to bear down tightly on the blade behind the cutting edge, or it fails completely in its mission. The angle looks rather sharp in the pic, too - the front of the CI should meet the blade at a tangent angle of at least 45 degrees on a standard-pitch plane.

You could try to fix it by carefully bending the end to a gentle curve, but if it's a new blade/CI combo, you should probably return it as unfit for purpose!

What model/breed of plane is it for?

Cheers,

I have a flat chip breaker myself. It was a custom made job I bought from another forumer. Luckily mine is completely flat.
You can as a temporary fix, use a strip of adhesive backed aluminium tape. This would work if the gap is very small.

Originally Posted by justonething

I have a flat chip breaker myself. It was a custom made job I bought from another forumer. Luckily mine is completely flat.
You can as a temporary fix, use a strip of adhesive backed aluminium tape. This would work if the gap is very small.

I guess a flat cap-iron could sort of work if both cutter & CI are absolutely, ridiculously, flat, but that is highly unlikely to ever be the case, & I doubt you will ever get full function out of it without a curve of some kind so you can lap the very end of the CI & the back of the blade to a sticky-tight fit across the full width. The merest gap on a close-set CI, will cause you endless grief. I doubt the lever cap could ever apply enough pressure to hold such a setup sufficiently tightly & if you tried screwing it down that hard, you'd be flat out working the adjuster AND run the risk of stripping the LC retaining screw to boot! Not an ideal situation.

A flat cap-iron such as yours might serve one of the functions of a cap iron, i.e., stiffening the blade, but it is unlikely to apply sufficient pressure with the lever-cap clipped down to get any significant pre-tension on the blade, so it's unlikely you could ever get your plane to work in the close set (i.e., 0.2-0.5mm) position, where it does most good in controlling tear-out. If it's a rough jack, you may be able to get it to work in a halfhearted way, but I doubt it would be a very nice plane to use for real work.

It was a failure to grasp just how tight he CI/blade fit needs to be that prevented me from getting close-set CIs to work for me for a very long time. I reckon a bit of a bend in your CI could help a lot. HOWEVER, be aware that the distance from the tip of the CI to the adjuster slot is crucial on a Bailey type plane. You have about a mm tolerance in either direction, and if you exceed that, you'll find yourself winding the thumb wheel off its stud, or hard against the frog, trying to set the blade. If you put a bend in the CI, make it very slight, as it will reduce that distance a little.

Cheers,

I think this pair might have been from a forum group buy, I bought it second hand. I'm not sure if I can bend it as it is 3mm thick. I will stick it in the vise shortly and give it a heave-ho. I should probably buy a metal working vice one of these days.

Cap iron and blade.jpg

It occurs to me that since it doesn't work right anyway, maybe I should just offer the cap iron up to a coarse grit belt sander and see how much effort it would take to thin out everything except the last few mm by enough smidgens to get the edge to sit on the back of the blade. Probably a lot.

as ian says, it needs a small bend

I believe these are the same ones that I got. Rather than using them together, I always pair the cap iron with a different plane iron, because like you said, they are a bit too thick together. If they are bent, you could try to reverse that by putting spacers at the top and bottom of the cap iron and tighten the screws to pull it back out again.

Many thanks for all of the replies and especially for the bending suggestion IanW. I think we can call this one a success!

I stuck the cap iron into the vice and gave it a pull and it bent surprisingly easily. I think I put the bend a little higher than would be optimal... but it works just fine. Took a few shavings and checked - there was nothing between the cap iron and blade. Gave the blade a proper sharpen, a bit of clean up on the cap iron edge and then put it into a #4 - there is just enough clearance in the mouth that you'd call it a finely set plane. I didn't mess around for the testing, straight to a piece of spotted gum and what a revelation. Full length shavings from the narrow edge and it cleaned up all of the tearout present. One of the faces still had the marks from a 3 TPI bandsaw blade, this cleaned up in a few minutes. There are two areas on the face that have a small amount of very shallow tear out but otherwise it handled the fiddleback like a champ.

Photos because who doesn't like photos! (I broke off a bit of the full length shaving unravelling it) You can see in the last pic there isn't even any dust on between the irons.

full length shaving.jpg

so many shavings.jpg

face planed.jpg

bravo - job done.

Yes, nicely done and thanks for the pics

Sent from my SM-A515U using Tapatalk

Glad to hear of a happy ending to your saga.

The intention must have been that the people who bought those blade/cap-iron sets do the bending, I cannot see anyone expecting them to have worked satisfactorily as you received it. That's a bit fraught, when folks like yourself don't even have a metal vise, but fortunately, mild steel bends pretty easily, as you've discovered.

Apart from the setting of cap-irons to get the best tear-out control (which I'm not going to get into; D.W. has already written reams on the subject ), I'd say the cap iron is the least understood part of the Bailey design. Most of the after-market cap-irons I see are poorly conceived, imo, with just a singe bend, not the swan-neck curve of the originals. I suggest there are two reasons Stanley made them the way they did:

One is because the cap-iron can sit flat on the blade over most of it's length, and not bend the blade when the screw is tightened (you can't just leave the screw loose, or the CI will slip when you try to adjust the cutting depth). This is what happens when you tighten a thick, single-bend cap-iron down on a standard blade: 11 cap iron single bend.jpg

A good impersonation of a banana! This combination is NOT going to sit well on the frog - it may be ok, depending on just where the bend is most severe, or it may cause problems with clamping the blade assembly firmly.

But by making a double bend in the right way, the assembly remains flat over most of the length (crucially, where it sits on the frog), and still have very good contact across the pointy end: 12 cap iron double bend.jpg

But there's more to it than that. The single-bend CIs can give the blade/CI assembly a distinct wedge shape, which means as you advance the blade, the pressure from the lever-cap eases, and when you retract, it tightens. Cammed lever caps cope with this to some extent, but I struck trouble the first time I made myself a you-beaut 1/8" thick stainless-steel cap iron to replace the two-piece CI in my new Clifton #4 (the people who made that bit of metal excrement had nfi about what cap-irons are all about!) My CI had a very distinct bend, but the Clifton blade is very thick, so it didn't curve, which gave the assembly a pronounced wedge shape. In addition, I got the distance from the end to the adjuster cam slot off a wee bit. To engage the blade, I had to almost screw the thumb wheel off its stud, and by the time the blade was cutting, it was loose! Eventually, after gaining some more experience & knowledge, I made a new CI with the "proper" shape and suddenly, the sow's ear became a silk purse!

If you examine an old Stanley or Record, you'll note that the top of that bend in the CI is cunningly placed so that when attached & set at a normal distance from the cutting edge of the blade, the lever-cap bears down right smack on the top of the curve. And it's a gentle curve, so that as the blade assembly s moved back & forth by the mm or so that it would travel in normal adjustment/use, the pressure remains close to constant. That's good for function & also makes for smoother, easier, adjustment. With a well set-up Bailey, you can spin the wheel with a finger tip & dial in the setting you want as you plane.

Making a precise double-bend CI isn't easy for most backyard warriors. To do it consistently and accurately, you'd need a good jig & a press. I've made a very simple jig which I press in a vise, after setting the CI blank & bending dolly up with copious amounts of duct tape: 8 CI bending 1.jpg

It's hard to get things dead-accurate with such a crude system. I can usually tidy it up enough after bending, with files, grinder & sanding, but occasionally, it all goes to hell in a hand-basket and ends up in the bin...

It's been a long road, with many a wrong turn, but between making planes from scratch & fettling others, I think I've got a far better grasp of the functions of each part than when I started (I guess any advance on zero is a gain ). But I'm sure there are still a few discoveries to be made before I put the tools away for the last time ...

Cheers,

Originally Posted by IanW

Glad to hear of a happy ending to your saga.

The intention must have been that the people who bought those blade/cap-iron sets do the bending, I cannot see anyone expecting them to have worked satisfactorily as you received it. That's a bit fraught, when folks like yourself don't even have a metal vise, but fortunately, mild steel bends pretty easily, as you've discovered.

Apart from the setting of cap-irons to get the best tear-out control (which I'm not going to get into; D.W. has already written reams on the subject ), I'd say the cap iron is the least understood part of the Bailey design. Most of the after-market cap-irons I see are poorly conceived, imo, with just a singe bend, not the swan-neck curve of the originals. I suggest there are two reasons Stanley made them the way they did:

One is because the cap-iron can sit flat on the blade over most of it's length, and not bend the blade when the screw is tightened (you can't just leave the screw loose, or the CI will slip when you try to adjust the cutting depth). This is what happens when you tighten a thick, single-bend cap-iron down on a standard blade: 11 cap iron single bend.jpg

A good impersonation of a banana! This combination is NOT going to sit well on the frog - it may be ok, depending on just where the bend is most severe, or it may cause problems with clamping the blade assembly firmly.

But by making a double bend in the right way, the assembly remains flat over most of the length (crucially, where it sits on the frog), and still have very good contact across the pointy end: 12 cap iron double bend.jpg

But there's more to it than that. The single-bend CIs can give the blade/CI assembly a distinct wedge shape, which means as you advance the blade, the pressure from the lever-cap eases, and when you retract, it tightens. Cammed lever caps cope with this to some extent, but I struck trouble the first time I made myself a you-beaut 1/8" thick stainless-steel cap iron to replace the two-piece CI in my new Clifton #4 (the people who made that bit of metal excrement had nfi about what cap-irons are all about!) My CI had a very distinct bend, but the Clifton blade is very thick, so it didn't curve, which gave the assembly a pronounced wedge shape. In addition, I got the distance from the end to the adjuster cam slot off a wee bit. To engage the blade, I had to almost screw the thumb wheel off its stud, and by the time the blade was cutting, it was loose! Eventually, after gaining some more experience & knowledge, I made a new CI with the "proper" shape and suddenly, the sow's ear became a silk purse!

If you examine an old Stanley or Record, you'll note that the top of that bend in the CI is cunningly placed so that when attached & set at a normal distance from the cutting edge of the blade, the lever-cap bears down right smack on the top of the curve. And it's a gentle curve, so that as the blade assembly s moved back & forth by the mm or so that it would travel in normal adjustment/use, the pressure remains close to constant. That's good for function & also makes for smoother, easier, adjustment. With a well set-up Bailey, you can spin the wheel with a finger tip & dial in the setting you want as you plane.

Making a precise double-bend CI isn't easy for most backyard warriors. To do it consistently and accurately, you'd need a good jig & a press. I've made a very simple jig which I press in a vise, after setting the CI blank & bending dolly up with copious amounts of duct tape: 8 CI bending 1.jpg

It's hard to get things dead-accurate with such a crude system. I can usually tidy it up enough after bending, with files, grinder & sanding, but occasionally, it all goes to hell in a hand-basket and ends up in the bin...

It's been a long road, with many a wrong turn, but between making planes from scratch & fettling others, I think I've got a far better grasp of the functions of each part than when I started (I guess any advance on zero is a gain ). But I'm sure there are still a few discoveries to be made before I put the tools away for the last time ...

Cheers,

Ian, without wanting to take over this thread,
Your advice above might help some of the Plane challenge guys.
Could you also put it there maybe under the Judges Corner??.

Cheers Matt.

Matt, a lot of that pertains to Bailey planes, but there are some aspects that might help someone who wishes to make their own cap-iron.

I'm happy to write up a little WIP on making cap irons & discuss the pros & cons of single & double bends, but I'm reluctant to use the 'judges corner' thread, I'd rather leave that for 'administrative' stuff. If it's ok with you & Bob, I'll make another 'sticky' thread called 'Tips & Techniques', where we can all share experiences (good & bad!) that might help others with their builds. Some of the "challengers" will have had their own lightbulb moments they'd be happy to pass around...
Cheers,

Originally Posted by IanW

Matt, a lot of that pertains to Bailey planes, but there are some aspects that might help someone who wishes to make their own cap-iron.

I'm happy to write up a little WIP on making cap irons & discuss the pros & cons of single & double bends, but I'm reluctant to use the 'judges corner' thread, I'd rather leave that for 'administrative' stuff. If it's ok with you & Bob, I'll make another 'sticky' thread called 'Tips & Techniques', where we can all share experiences (good & bad!) that might help others with their builds. Some of the "challengers" will have had their own lightbulb moments they'd be happy to pass around...
Cheers,

Ian,
That’s a great idea Tips and Techniques Sticky.
I will make an executive decision on behalf of me and Bob.
Go for it ).

Cheers Matt