Ideas for 2 part staff mechanism.

[W.duBois]

A question to all.
I am planning to do some hiking this summer, and I want to take a walking staff with me. When the staff is not needed I want to make it so that you can disassemble it in two parts and attach it to your backpack.

I am pondering about this for a few weeks now. How can I make it so that the joint won't be visible to much, or worse, create a weak point in the staff? My idea was to get some inner and outer threaded metal rods and insert both into each part of the staff. My concern is that by drilling holes into each part I might weaken the staff to much. The problem is that the holes need to be quite long to distribute the forces at the joint evenly, but by making long holes I could also weaken the wood to much. And how can I join metal and wood firmly together?

I am planning to use Holly (Ilex) for it's large weight, resistance to flex and inconspicuous color (don't want it to stand out to much, last thing I need is that customs sees it as a weapon or something..)

Has anyone of you ever made something like this? Or do you folks have some additional ideas or tips?

Thx.

[mpounders]

I've never made one to come apart. I know you can get threaded inserts (female) and use threaded rod to connect... you might look at hardware used for making pool cues that break apart...... something like Uni-Loc Joint Pin<br>& Insert

Or, there is a post in this same forum concerning wooden screw threads ...taps and dies.... might be a problem with the tapping though? strictly ideas instead of practical experience!

[nameless]

Originally Posted by W.duBois

A question to all.
I am planning to do some hiking this summer, and I want to take a walking staff with me. When the staff is not needed I want to make it so that you can disassemble it in two parts and attach it to your backpack.

First thing that comes to mind is one of those cheap oriental pool que/cane with ball/brass top. One fits inside the other andand a tip for the ground screws onto the bottom. Can be used for hiking...

I am pondering about this for a few weeks now. How can I make it so that the joint won't be visible to much, or worse, create a weak point in the staff?

Now we have a problem with tradeoffs. There is no configuration of seperable parts that can compare in strength to a good solid single stick.
If you have three joints (not uncommon for 'travelling canes', with their own little carrying case), pound for pound, the stresses are lesser on any particular joint. The domino effect leaves us with a cane with the inherent strengths of the joints of which they are constructed.
Another problem is the 'invisible' joint. I have made successful invisible joints on sword-canes and gun-canes, but the 'strengths' of such canes are their 'gimmicry'. The only high point is that when the 'matter' hits the fan, or the cane gets a good thwack, one has a broken shaft on the ground and a sword/gun in one's hand. Not handy in the creek-bed.
An invisible joint has no metal reinforcing rings on either end, there, ordinarily, to... reinforce the joint. Sword canes have a bit of metal on the inside of the shaft portion to accept the blade, but it is seldom a screw catch, which is what, I assume, you will want, as they seem the most secure. If anyone has any updates on joints that might be stronger then threaded, I hope that they will chime in.
Perhaps you could buy a pool cue joint, some are 'quick release' if I remember correctly, and paint it whatever color the stick is, or anodizing, depending on how serious you are.
Just in, perhaps a long (3" at least) very coarse threaded bolt extending from one end, and a drilled and threaded hole, yes thread the wood! With a threaded hole of the appropriate length and enough 'meat' left on the stick around the hole, it might just work, and provide an invisible and strong joint if everything fits up tight. Ultimately, that is the greatest configuration for strength, accuracy of prep and fitting. It's 'cabinetry' as compared to 'carpentry'. heh.
The bolt/threaded rod (usually too soft) must not be so small (narrow) that it would bend under the pressures involved as to put differing stresses on the threaded hole.
If there is some kind of steel inner-threaded tube of sufficient wall thickness to barely take up space in the drilled hole, I'd love to hear about it. Then simply epoxe that into the hole... But barring that, i think that the threaded hole would be quite strong. Not, of course, as strong as without the joint. I hope that you don't have to whump a bear with it.
It would make me uneasy to hear a bear laughing at me!! *__-

My idea was to get some inner and outer threaded metal rods and insert both into each part of the staff. My concern is that by drilling holes into each part I might weaken the staff to much.

As I said, the ratio of wood surrounding the inner sleeve is dependent on the type of wood and it's characteristics, grain structure, strength of tubing and bolt, pressures that will be applied (and then making it strong enough to withstand twice that), etc...
A big series of tradeoffs.
My guess is that if you can find a source for those threaded joints, the cane makers around will be willing to purchase them from you. I would. Three handy sizes; common, hefty and ludicrous! (like women's undies)

I am planning to use Holly (Ilex) for it's large weight, resistance to flex and inconspicuous color (don't want it to stand out to much, last thing I need is that customs sees it as a weapon or something..)

A decorative metal reinforced joint looks like you aren't trying to hide anything, whereas your hidden joint, even if it passes the blind inspectors, will show up on a metal detector; beep-beep-beep and you are a guest of Homeland Security for months or years, tortured, fading from the memories of all but a small circle of friends...
Unless you do some sort of wooden peg and hole arrangement. If the shaft is 2" in diameter, perhaps youd have the room...
Customs has seen take down canes before.

Oops, ran out of words...

[Waitpinga Whittler]

G'day mate,

You can join stick and cane shafts without sacrificing strength, but there are some conditions. Putting metal inserts into drilled shafts can make the stick weaker if not done properly and with a good deal of attention paid to tolerances. The best way I've found to make a blind joint is as per the attached drawing. (Pardon its crudity, but I couldn't get my CAD files to save as JPEGs so I had to use 'Paint' with which my skills are rudimentary)

You need a solid metal bar of suitable diameter, preferably around, but no more than, half that of the stick/cane shaft. I'd suggest around 250 mm long This has to be cut in half, one half drilled and tapped while the other half is turned and threaded so as to form a male/female screwed metal bar (as per illustration). The if you make the length of the thread about 50 mm, this will leave you with about 100mm on each side of the joint in the metal rod when its screwed together. The metal you choose isn't all that important so long as the dimentions are sufficient to convey strength to the joint.

Next your stick/cane shaft will need to be cut. This cut needs to be SQUARE to length of the shaft so that when re-assembled there will be no gaps at the joint. Drill your shaft, top and bottom, also square to the shaft, preferably no more than 0.3mm larger diameter than the diameter of your metal rod.

YOU MUST HAVE SOME PLAY BETWEEN THE SHAFT HOLE AND THE ROD TO ALLOW THE ACCESS OF EPOXY GLUE. However too much play here will create problems in alignment later. Too little play will put undue pressure on the walls of the shaft and risk a break out of the metal rod. You are relying on the glue bond to make the wood and metal an integral unit with out the metal putting an outward pressure on the walls of the wooden hole as would occur if this was screwed into place. AVOID THREADED ROD FOR THIS REASON!

Set the metal rod halves in the shaft holes and two pack epoxy them in 0.2mm below the level of the wood. Once the glue is dry, you can assemble you stick and final fit the joint with files/sand paper, both on the face of the joint and also on the outside of the stick where the two haves meet. If you get it right, you will hardly be able to see the joint at all.

I don't know anyone commercially making this kind of metal fitting. Its a design I came up with after a lot of thought and a bit of trial and error. I called on the services of a mate with a metal lathe for this when I did one as a commission. The whole thing worked out quite well, but as I said earlier, you have to pay attention to your angles and tolerances or you can get into a world of trouble with the finished joint not lining up and leaving you with an unsightly gap!

Anyway, good luck with it. The process is a lot easier if you have the use of a lathe to keep things centred and square, but its possible without one if you're careful. Its a lot of work but if you have to have a multi-piece shaft, its worth it I reckon. A whole LOT stronger than anything commercially available that I could find which is why I went this way in the first place.

[nameless]

Originally Posted by Waitpinga Whittler

You can join stick and cane shafts without sacrificing strength

I don't think so. There will always be strength loss at the joint, compared to an unbroken stick, but it needn't be much.
Where the weakness comes into play in your joint, as I see it, is that you have an unbending piece of metal (when screwed together) within a flexible wooden shaft. When the wood of the shaft flexes, the metal insert will not, putting particularly local pressure from the but-ends of the insert that are merely end joined/glued (the weakest joint) to the wood at the weakest point, where the thin wooden walls meet the solid wood. Picture a nail in a plastic straw, now bend it ans see what happens. Where the straw bulges and deforms, the wood will fail. The flexing of the wood can also crack away the thinner weaker wooden sheathing for/from the insert.
You are right in leaving as much wood as possible, for strength.
Perhaps a rounded configuration of the ends of the insert and the corresponding ends of the hole that accommodates them would add some strength at that weakest and critical juncture.
It is a better joint than many, but, again, none are as strong as an 'unbroken' stick.
IMHO.

[Waitpinga Whittler]

Joined as I outlined, the joint is the strongest part of the shaft, particularly if you take the trouble to make the metal inserts at least 100mm either side of the join. All commercially produced staft joiners I've seen are at most a couple of inches... half what's required. To make matters worse, they often have wide threads designed to be screwed into the timber, which puts an outward force on the walls of the bored stick, thus creating a weakness and setting one up for a split shaft. On the other hand, if the metal insert is fractionally smaller than the bored hole in the shaft (0.3mm) and the space completly filled with a good epoxy, the bond between the metal and shaft will be stronger than the original wood. If it breaks anywhere, it will break above or below the metal insert and then only under circumstances which probably would have broken the un-modified stick in the first place.

If you want unbreakable... use a collapsing ski pole, otherwise, this is as good as it gets for sectioned sticks.

Try it...don't try it... its no skin off my nose either way. All I am saying is it works.

[Claude]

While it's not wood or carving, something like this might be appropriate.
Claude

Folstaff Wading Staff : Cabela's

[W.duBois]

Thank you all for thinking with me, appreciate it.

Originally Posted by nameless

A decorative metal reinforced joint looks like you aren't trying to hide anything, whereas your hidden joint, even if it passes the blind inspectors, will show up on a metal detector; beep-beep-beep and you are a guest of Homeland Security for months or years, tortured, fading from the memories of all but a small circle of friends...

Hehe point taken. Making the joint totaly invisible is a bit to much, I see that now. As long there isn't some huge 'hinge' or other kind of mechanism visible I am happy with metal rings on each side of the joint for example, or even some of small collar.

Originally Posted by Waitpinga Whittler

Next your stick/cane shaft will need to be cut. This cut needs to be SQUARE to length of the shaft so that when re-assembled there will be no gaps at the joint. Drill your shaft, top and bottom, also square to the shaft, preferably no more than 0.3mm larger diameter than the diameter of your metal rod.

YOU MUST HAVE SOME PLAY BETWEEN THE SHAFT HOLE AND THE ROD TO ALLOW THE ACCESS OF EPOXY GLUE. However too much play here will create problems in alignment later. Too little play will put undue pressure on the walls of the shaft and risk a break out of the metal rod.

Correct, lining the upper and lower part is going to be tricky. My idea is to leave the staff as rough as possible before making the joint, so I have some room to play when drilling the holes. After the joint is perfected I can proceed with shaping the staff as I desire. Still, I will need to be darn careful not to sand away to much wall material..

Good idea about leaving some play in the shaft nameless and Waitpinga Whittler. I wonder, isn't epoxy to hard for some 'play'? What about more flexible (rubbery) types of glue? Also, nameless mentioned that the threaded rod should not be so small (narrow) that it would bend under the pressures because of differing stresses in the threaded hole. Wouldn't a small diameter rod flex WITH the wood instead of a thicker rigid rod? Perhaps giving it flexibility will soak up tension, like impacting the thick skull of nameless' angry bear.

This is all just theory, but theorizing stuff like this gets my blood going.

[nameless]

Originally Posted by W.duBois

Making the joint totaly invisible is a bit to much, I see that now. As long there isn't some huge 'hinge' or other kind of mechanism visible I am happy with metal rings on each side of the joint for example, or even some of small collar.

If you can live with a metal sleeve, make sure that it extends beyond the inner limits of whatever fastening system you choose (for an inch or so), keeping in mind the length necessary for the strength of the inner fastener and the inherent weakness at either end, which can be moderated by the metal sleeve.
I do the same on my canes, there is a weak point at the bottom of the hole bored for the bolt, and a weak point where the carved wood begins to allow a flush fit for the ferrule (the wooden 'ledge' at the top of the ferule). I have the ferule/sleeve extend further up the stick than the bolt reaches for maximum strength. Same principle as what you want to do.
That combo should give you the strongest joint, in my opinion, according to my experience.

Wouldn't a small diameter rod flex WITH the wood instead of a thicker rigid rod?

Yes, to an extent, but then the majority of the stresses will be on the thin wooden walls surrounding the joint and at the place where the wood meets each other. There is no strength from the wood at that point and the bending rod will cause the joint fail quicker.

This is all just theory, but theorizing stuff like this gets my blood going.

I find that the initial 'theorizing' and homework saves much time and blood and sweat and tears later on. First engage the brain, then the hands (or mouth!) if possible.. *__-
Happy wood
peace

[Waitpinga Whittler]

Originally Posted by W.duBois

I wonder, isn't epoxy to hard for some 'play'? What about more flexible (rubbery) types of glue?

When I said 'play' I meant while the glue is still wet. You want enough glue to contact the whole of the external of the rod/internal of the hole. At the same time, if there is too much play there is a real possibility that the rod will not dry perfectly aligned with the hole and thus the two faces of the joint will not meet square when assembled. That's why I recommend a max of 0.3mm difference between diameter of rod and hole.

Epoxy is the only thing I would trust as being strong enough.

The rod will not flex to the same degree as the stick, no matter what. I think the concern that Nameless is expressing is that inside the shaft, at the bottom of the whole, where the rod ends, either side of the actual joint, will be the 'weak' point. That is the point at which ANY difference in flexibility between the two materials will be the greatest and therefore the most likely to fail under stress.

My point here is to deal with dimentions in the stick that are large enough that they won't flex under normal working conditions... say about and inch and a half. (This will vary depending on species of wood... yet another variable you are going to have to make a decision on). If your after 'thin and whippy', this is definately not the way to go. Similarly, if you are wanting a 'defensive' weapon, forget the joint. On the other hand, if you want a walking stick to use as a stick to assist you in walking, then this will work.

I'll be interested in seeing your results eventually. I'm sorry I could not post a photo of the ones I've done as they were both commissions and have long ago passed out of my hands. The fact that I've not heard back from their owners suggests to me that they have had no difficulties with them.