Thread: Steel bodied shoulder plane

Originally Posted by tony_A

......I am curious to know what you are aiming to achieve in terms of plane performance with your less than 10 degree skew. Understand that will mean a more gentle entry into the cut than a straight blade but wouldn't have thought it would add much in terms of a slicing cut vs a shearing cut (no skew).....

Apologies, Tony, I didn't explain myself very well!

To get a skewed mouth on a plane, you 'tilt' the bed & this is where the confusion arises, because this tilt is usually referred to as the "skew angle". The angle the mouth makes wrt the axis of the plane is also referred to as the "skew angle", but the two are not the same thing. The same skew of the bed will produce a different amount of mouth skew as the bed angle is reduced. For a blade with a nominal 45 degree bed and 10 degree tilt, the mouth skew will be much less than if the blade bed is 12 degrees and the same amount of tilt. For example, my panel plane (nominal 45 * bed angle), has a bed skew of 10*, and a mouth skew of about 12*, which is not a lot of skew, but seems to be a fairly typical angle for badger planes (which is what I started out to make before I changed my mind & kept both sides entire). I put the same 10 degree tilt on the first shoulder plane I skewed (15-16* bed) and the mouth skew is more than 35 degrees: mouth angles.jpg

That's getting a bit extreme, imo, the leading point of the blade gets rather acute & fragile.

Skewing blades involves a bit more than simply tilting blade beds, it can bring up challenges you may not consider until you come to them. This was the case with fitting a lever-cap in my skewed panel plane. L side b.jpg

I have never held an old infill with a skewed blade in my hands, so I was working on pictures & guesswork when I made this, & had not thought the whole thing through thoroughly until I started. The lever cap looks simple enough when done, but it took a deal of "standing & staring" at my mock-up to decide how I'd actually do it. The skewed axis of the LC pin means it is only really parallel to the bed at the point of closure (because that's where you set it to be). When you loosen it & rotate it to extract the blade, the trailing side of the LC runs into the side. It has to have a bit trimmed off that side to allow enough rotation to get the blade in & out. The greater the skew, the worse the problem. (Using a wedge instead of a LC would be an easier solution, but I was determined to use a LC.)

So that's why I advocate spending a bit of time with mock-ups when venturing into new territory. A few minutes spent playing with some wood & bits of cardboard can save much angst & gnashing of teeth.....

Cheers,

OK, I decided I should try to explain this business of increasing mouth skew better in the second edition of my manual (due sometime this century!) so I spent a half-hour making a couple of props that I hope will illustrate the point.

Lets say we are making a couple of skewed planes, one a bench plane, with a bed angle of 45*, the other a rebate with a bed angle of 15*: a.jpg

If we give both beds the same tilt or skew angle, they look just the same from the back: b.jpg

But very different from the sole: c.jpg

The 10* 'tilt' to the low-angle bed has produced a mouth skew of ~40* wrt the plane's axis, which is excessive, imo. A mouth skew of somewhere between 12 & 20* is adequate; 25* would be ok, but my own mucking about has not convinced me there is any value in going any more than that. The ~12* of my panel plane is pretty conservative, but it works very well, & handles cross-grain with much more aplomb than the nearly identical plane I made with a straight blade (an experiment with n=2 is not an experiment worth much, but that's the best I can do at this stage. ) d.jpg

Interestingly, although shoulder planes could be had with skewed blades back in their heyday, I have read in a couple of places that they were not a regular production item, and had to be specially ordered. From the tiny number of skewed SPs that survive, it has been suggested that very few skewed models were ordered!

However, I reckon every self-respecting planemaker has to make at least one skewed-bladed example, for the satisfaction of doing it, if nothing else. They are a bit more challenging to make, though not all that much if you plan the thing properly, instead of taking the bull-at-gate approach I used for #1. But I suspect you will not find it a major revelation when it's finished, compared with your current plane. The bother is on-going, too, you have to be more meticulous when grinding & sharpening the blade, because, like the mouth skew, any small deviations are amplified, and you can easily find you don't have enough lateral adjustment to compensate & be forced to re-grind (damhik!).

There is someone who loves my skewed SP very much, though. Our 6 yr old grand-daughter is fascinated by the curly shavings it makes: curly shavings.jpg

I think she would reduce all the wood in my shed to spills if I let her go.....

Cheers,

Thank you Ian, That is much clearer. You are generous with your time and knowledge. As you said earlier, it would be great if those interested in plane building could get together in one shed from time to time.

No worries Tony. What we really need is a simple way to lay out the blade-bed for any given mouth angle. I could have done the trigonometry 50 years ago, but my brain just goes to mush at the thought, these days. So the no-maths method I used on the last couple was to take a block of wood like the above example & set out out the desired mouth skew-angle first on the 'sole'. Then I used a template to scribe the bed angle from the mouth to the back of the block on each side. Connecting these two lines across the back of the block gave me the skew angle for my bed. I didn't need to know what the angle was in degrees, I simply set a sliding bevel to the line & used that to set out & check the angles of the metal wedge used for the core.

When cutting out the escapement hole in the sides, I didn't worry about trying to cut the skew angles on the part of the sides that project along the blade-bed. I just left a bit of extra metal so I could file them flush with the bed after joining all the pieces. That's one of the most fraught parts of the build, as you probably learnt; even for a 'square' bed you have to file sooo carefully & not hit your nicely-prepared core.

My description probably sounds cumbersome, but it was quite a simple process, really. It's not moon-rocket precision, I may have ended up plus or minus a half-degree, from my nominal mouth angle, but that's neither here nor there. A degree more or less of skew won't make any discernible difference to function, the main thing is not to end up with a mouth with twice as much skew as you were aiming for, like I did on #1!

Cheers,

So did you use a standard shoulder plane blade and waste half of it by grinding a skew edge is was there a better way.

Originally Posted by tony_A

So did you use a standard shoulder plane blade and waste half of it by grinding a skew edge is was there a better way.

As it happens, I made the blade for the little one above from a scrap of HSS left over from another project, but all the other skewed blades I've done had the skew ground onto what was a 'straight' blade to begin with. I haven't any "better" way..

I suppose you are "wasting" a bit of blade metal, but it doesn't knock all that much off a new blade if your skew angle isn't extreme like my first example. Rebate plane blades don't get the sort of constant sharpening/re-grinding a busy bench plane blade gets, so they typically last several generations - you won't run out of blade on your new SP any time soon.....

Cheers,

Thanks again Ian. As you know with the help you gave me on my wooden shooting plane making the blocks is the best way to not only see how things work but also to see how small changes can have a big effect

Re-vitalising this thread for inspiration. The photos are mind blowing. Incredible craftsmanship!

Well, why not?

It's time we had a few members working away on some plane-making projects again. I guess we won't see the heady days of the "great plane challenge" of 2020 again - we don't have lock-downs to keep us in our sheds for days & weeks at a time!

For more inspiration & ideas on shoulder-rebate design, take a look at Picko's thread in the said "challenge" if you haven't come across it already. I reckon he deserves top marks for both lateral thinking & use of "found" material. There are always other ways to skin the proverbial cat, & I love seeing how other folk solve similar problems. I wish I had a $ for every time I've said to myself "Why didn't I think of that!?"

And don't be discouraged by the blokes who use machinery - if you have them & can use them, it can certainly make life easier (or screw things up faster!), but my 'mission' has been to convince people that you can achieve perfectly good results with hand tools, and the results can be just as accurate if you work carefully.

So c'mon fellers we need some more projects underway, things have been a bit quiet since more normal life resumed (for most of us).....

Cheers,

Have been away for a little while and saw Johknee's comments on my return which motivated me (Albee it a little slowly) to give a follow up having used the plane for a while. Part of the reason for building the plane was that I had a work bench build in the planning with multiple tenons required. Overall I'm quite happy with it, and it performed quite well squaring the tenons. Although, its the first shoulder plane I've used so cant compare it to anything else.
It did have one annoying flaw, and the experienced plane users following this thread likely to have picked that up straight away. The plane has an adjustable mouth and I hoped that a clamping nut would give enough pressure to hold the mouth setting. But alas, if the front on the plane bumped into the work the moveable front sole would push back against the blade thus closing the mouth and taking the edge off the blade. So a modification was required, drilled and threaded a hole in the seat of the front sole then screwed a cap screw. Cut a corresponding hole in the front sole that the cap screw head would locate in and then an adjusting grub screw in the front sole to set the rear limit or mouth opening. Photos below probably give a better explanation.
IMG_6868.jpg

IMG_6867.JPG

Having access to metalwork machines was be very handy for some operations but a fair bit of hand work was still required. Indeed its humbling to note that Ian W has made numerous planes that are every bit as good as mine (better actually) using no more than hand saw and a file and I bet he could build one in less time than it took me. There are numerous other examples of planes on this forum made with hand tools. So while metal work machines are brilliant for some things and there's a whole heap of new skills to learn, they are not necessary by any means.

Tony, these sorts of follow-ups are invaluable, imo, it makes the lessons much less painful for others! I wish there had been as much info & experience available to me as there is now when I made my first shoulder plane...

Originally Posted by tony_A

...... The plane has an adjustable mouth and I hoped that a clamping nut would give enough pressure to hold the mouth setting. But alas, if the front on the plane bumped into the work the moveable front sole would push back against the blade thus closing the mouth and taking the edge off the blade....

To be honest, I didn't really note the "exposure" of your toe piece at the time, but I should have! By the time I made my first SP, I had had a fair bit of experience with a block plane with an adjustable mouth & had discovered that annoying little feature of the sliding piece being slammed into a freshly-sharpened blade.
Maybe I thought it was only a klutz like me who would be careless enough to do that....

So, a design feature of V.1 was to extend the front piece down to protect the slider: Original front.jpg

This was my first first foray into metal dovetails & I made two discoveries. The first was that it is very unwise to use the hard 380 alloy for dovetailing. You can get away with it if you use a more malleable metal for the other part, or get a very close fit & need to do minimal peening to close them, but my fit was not at all in that category, & the brass started to split & flake long before I got them properly closed up. That may explain why it was many years before I attempted metal dovetails again! My second discovery was that it's not a good idea to fill in the voids with solder - it just makes your shoddy work more obvious!

However, the front piece did it's job & saved my blade from 'accidents'.

years down the track & after a few somewhat more successful metal dovetails, that first attempt became too much of an embarrassment & I just had to do something about it. The front was only 1/8" thick, so I just cut it off & inserted a new bit thick enough to rivet through. Hiding rivets is far easier & now the front is much neater:

Nose job.jpg

My metalworking had advanced a little since 1983, so I was able to jazz it up a bit more with a coved trim along the toe, though I couldn't do much about the rather uninspiring side profile I'd chosen:

6 SP.jpg.

Originally Posted by tony_A

...... So while metal work machines are brilliant for some things and there's a whole heap of new skills to learn, they are not necessary by any means....

Absolutely - that's the message I keep pushing! Metal is in some ways easier to work with than wood, mistakes happen more slowly, so there's a chance of catching yourself in time (though not always! ). Some decent files and steady work & it will amaze you what can be achieved in far less time than you may expect. Of course my baby metal lathe makes it easier to add nice finishing touches like knurled thumbscrews, but there are ways of making these that don't involve a metal lathe. There is one powered tool I wouldn't like to be without & that's the drill-press - again not essential, but it does make life a lot easier....

Cheers,
Ian

I've only just seen this thread. My goodness that's a fine looking plane. Those are some sexy thumb screws. I bet you could manufacture and sell them if you could make them cheaply enough. I'd buy them!

Originally Posted by BEM

I've only just seen this thread. My goodness that's a fine looking plane. Those are some sexy thumb screws. I bet you could manufacture and sell them if you could make them cheaply enough. I'd buy them!

Thanks BEM. As for selling stuff, not interested. Ive a whole heap of my own projects that Ill struggle to finish in this lifetime.

Originally Posted by tony_A

....... Ive a whole heap of my own projects that Ill struggle to finish in this lifetime....

Know the feeling only too well, Tony....

BEM, Having made one or two SPs, I can finish one in half the time it took to make the first plane, but there are still too many hours of work in hand-building something like this to make it profitable without charging prices few would be willing to pay.

I have made a few SPs for friends, and sold a few of my other planes that were "excess to requirements", but I was only seeking to recover the cost of materials & consumables. The hours of my time that went into them were paid for by the pleasure of mucking about in the shed. I suspect that would soon evaporate if I were driven by commercial imperatives.

Maybe when Tony has made a few hundred more planes & has the reputation of a Bill Carter he can charge the sort of prices that would make it profitable.....


Cheers,