Author Topic: Has anyone here made a deflex takedown sleeve?  (Read 918 times)

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Offline Aussie Yeoman

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Has anyone here made a deflex takedown sleeve?
« on: May 13, 2024, 06:51:31 am »
Hi folks.

Exactly as the title says - curious if anyone here has made a takedown sleeve that has deflex built into it. As opposed to setting deflex into the billets.

Juri made and posted one on one of the other forums many years ago but he later reported it not performing as well as he'd hoped. Not that it couldn't be made to work...

Thanks!
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Offline Hamish

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #1 on: May 13, 2024, 07:55:17 pm »
H'mm. Sounds like a tricky task. Never seen or even heard of such a feat. What approach did Juri use?

Metal sleeve probably wouldn't work, unless it was cast.

Maybe a cut down 1 piece, with a fg wrapped take down handle?

Offline Aussie Yeoman

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #2 on: May 13, 2024, 08:47:29 pm »
He had a square tube. From one side he cut out a gusset and then bent it to close up the gap.

I was thinking about a FG option too. Might try it. The other option is to heat up some tube/pipe in the forge and bend it with a suitable bit of bar in it so it doesn't collapse in the wrong ways.

Then last night I saw that someone else used a strip-style marine hinge on the back to good effect.

So it seems there are a few options.
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Offline Aussie Yeoman

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Articles for the beginning bowyer, with Australian bowyers in mind:

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Offline Hamish

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #4 on: May 14, 2024, 07:03:31 pm »
Lovely looking bow, I can see why you'd like to try something similar.
My only worry with that method  would be the potential wear on the wooden end that gets repeatedly inserted, then taken apart. I imagine it would be not as harsh with a fg wrap handle( never heard it mentioned as a problem with fg wrap handles, but the metal sleeves always seem to have, inner sleeves to prevent wear).

If you can find tubing, where the next size down can telescope back into the main tube that might solve the problem. It depends on how the handle as a whole responds after bending, and whether you can easily get the pieces back apart.

Another idea, instead of bending the tube into deflex, you could saw through the tube, through the top, and sides but leaves the bottom side intact. Then you could bend it, and then weld the sides up.

Very interested in seeing what you come up with. I think I have met you at the  Wiseman's Ferry shoot back around 2007-10, we had a discussion about Native Australian bow woods, eucalypts and their tendency to sometimes chrysal even if the bow is perfectly made?If you are the same guy I remember you had excellent bowyering skills, blacksmithing/knifemaking skills and a sharp mind.

Offline Kidder

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #5 on: May 15, 2024, 12:07:39 am »
Simon has one on his website. Rather than angle the tubes he deflexed it at the handle. Hereís a link to his build.
https://primitive-bows.com/osage-take-down-hunting-bow-n0-78/

Offline Aussie Yeoman

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #6 on: May 15, 2024, 04:49:26 am »
Quote
My only worry with that method  would be the potential wear on the wooden end that gets repeatedly inserted, then taken apart. I imagine it would be not as harsh with a fg wrap handle( never heard it mentioned as a problem with fg wrap handles, but the metal sleeves always seem to have, inner sleeves to prevent wear).

Yeah I'd worried about that too. I was wondering whether some micarta or phenolic shims on back and belly would alleviate that. I'd like to stay away from FG if I can - the thought of the dust gives me the heebie-jeebies.

I just did some CAD work. If I glue up a 66" stave with 4"reflex I'd need to angle a tube by -6.9 degrees from straight. For a 1" pipe, this means a pretty small wedge out of the belly side of the RHS. Not impossible though.

Quote
Simon has one on his website. Rather than angle the tubes he deflexed it at the handle. Hereís a link to his build.
https://primitive-bows.com/osage-take-down-hunting-bow-n0-78/

That's a really nice build and accomplishes the design brief. Thanks for sharing! I'll add it to the list of candidate options. It would need some creative geometry to work the angle in. But, as is obvious from the tutorial, achievable.

I was thinking more about the marine hinge option. It occurred to me that potentially, the knuckles and barrel of the hinge could be a weak point. We could remove the weak point by just using a steel plate, bent or forged to shape and secured with threaded inserts. One on the back for sure, and potentially one on the belly if it were needed. But, I don't expect it would be needed, as most of the hinged options in TBB and modern glass bows don't seem to have them.

Quote
I think I have met you at the  Wiseman's Ferry shoot back around 2007-10, we had a discussion about Native Australian bow woods, eucalypts and their tendency to sometimes chrysal even if the bow is perfectly made?If you are the same guy I remember you had excellent bowyering skills, blacksmithing/knifemaking skills and a sharp mind.

You're very generous with your compliments but I'm pretty sure we've only met online. At the very least, I've never made it to a Wiseman's Ferry shoot.  :( We'd have exchanged notes on Ozbow, PP and here. I think we have exchanged correspondence on Aussie woods' tendency to chrysal. The tree-split staves I've used have chrysalled despite working admirably. Funnily enough, I and my students have only ever had chrysals where there's a terrible hinge when making boo backed ironbark or spotted gum bows.
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Offline Hamish

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #7 on: May 15, 2024, 10:19:27 am »
Yep, I have definitely talked with you on Ozbow, and I remember you came up with plenty of good ideas, especially regarding bow design.

Hinges are definitely a good idea for takedowns. They used to be available commercially in the States. None of them needed threaded inserts, but that doesn't mean its not a good idea, especially with your earlier proposed application. I think most guys on here could fashion a pretty decent hinge with hand tools, files and hacksaws, given lots of time and patience. A chunk of 4130 would be ideal(not cheap), heat treated to around 35-40Rockwell, for maximum toughness, but still workable with files etc. The other methods for takedowns discussed in the thread would be quicker to make.

I have two models that I have never used. One is a 3 piece articulation. The centre section is rectangular has 3 pronged finger joints on both ends, that interlock on either side with the securing plates. Small pins go through the joints on either side to create a hinge. The articulation can go into a deflex handle shape. This style could be made in with simple tools, and a file guide for accuracy.

The other one I have is a precision "Connexion" hinge, that has been done on a milling machine. A cnc mill could churn them out. Hard to explain, but it is in 2 separate halves that slide in together from the side in the L shaped position, but lock in when the hinge is folded flat into the shooting position. Really precisely made, can go into a slight deflex, or flat They were used on Robertson Stykbow longbows for a really long time, but the guy who makes the hinges must have retired, because they aren't available anymore. They come with titanium screws. Not sure if the hinge is stainless or titanium.

Offline Aussie Yeoman

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #8 on: May 15, 2024, 11:18:17 pm »

I have two models that I have never used. One is a 3 piece articulation. The centre section is rectangular has 3 pronged finger joints on both ends, that interlock on either side with the securing plates. Small pins go through the joints on either side to create a hinge. The articulation can go into a deflex handle shape. This style could be made in with simple tools, and a file guide for accuracy.


I'm sorry to say I don't quite follow. Could you do me a sketch? I'm sure that as soon as I see it I'll be all "oh yeah of course!" with a slap of the forehead.

Yeah I've managed to find only a precious few photos of the connexion hinge. I heard the screws were titanium because stainless screws would break. I think the hinges themselves were stainless though.
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Offline Hamish

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #9 on: May 16, 2024, 07:44:01 am »
Yeoman, If you send me your email, or phone # via private message on PA, I can send photos, measurements. Total boomer when it comes to tech, posting photos on the internet :D

Offline Bob Barnes

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #10 on: May 16, 2024, 10:35:15 pm »
I think that I have a connection hinge, less the screws, if there are any questions about it...
Seems like common sense isn't very common any more...

Offline mmattockx

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #11 on: May 17, 2024, 12:12:25 am »
Hamish's hinge pics. I will let him explain what we are looking at, but there are two designs. One looks to be permanently pinned while the other one will separate into two pieces when opened far enough.












Mark

Offline Hamish

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #12 on: May 17, 2024, 01:26:20 am »
Thanks for that Mark, much appreciated. I can post exact measurements if anyone is interested?

I was hoping someone would still be making these, but I haven't seen any advertised for years. I have been keeping them around unused as master copies, in the hope of getting some professionally made.

From memory there were 2 replica hinges being commercially made, based on originals from the early to mid 20thC. One was called a New Moon Hinge. Not sure if the black oxidised hinge is a New Moon, or if it's the other one, that  I can't remember the name.

The Connextion hinge is a lovely bit of gear. Flawlessly made, beautifully finished. I remember thinking it was quite expensive when I bought it, maybe $100-120USD+ shipping to Australia. If it was made pre cnc days then it's done by an extremely skilled machinist. Even so that would be a good price 15 years ago if it was made on a cnc mill.


Offline Aussie Yeoman

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Re: Has anyone here made a deflex takedown sleeve?
« Reply #13 on: May 17, 2024, 10:35:09 pm »
There's still a Connexion-style hinge being made by a broadhead manufacturer (not sure if I can say their name or not). The hinge is not on the website but if you email they'll send a brochure.

Still costs $100USD. There's a straight layup version and a version that will accommodate up to 11 degrees past flat.

That three-plated hinge looks fascinating. The pins must be mighty tough indeed.
Articles for the beginning bowyer, with Australian bowyers in mind:

http://www.tharwavalleyforge.com/articles/tutorials