Primitive Archer

Main Discussion Area => Bows => Topic started by: simk on May 04, 2018, 01:05:07 am

Title: Deflexing a Stave
Post by: simk on May 04, 2018, 01:05:07 am
Another try...
Title: Re: Deflexing a Stave
Post by: simk on May 04, 2018, 01:06:20 am
more pics
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 08:52:15 am
Neat idea. The square ends of the insert kinda bother me but it's all in compression I suppose. I wonder if a hand shocky bow would crack one of those butt joints. Just speculating though. Good job. :)
Title: Re: Deflexing a Stave
Post by: PatM on May 04, 2018, 09:03:58 am
  Better to do a  rounded scoop out of the area and then fill it with a crescent.
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 09:09:25 am
Wouldn't that have a tendency to pop out, like a pip squeezed between your fingers. I realise it's unlikely and probably wouldn't happen, just thinking out loud.
Title: Re: Deflexing a Stave
Post by: PatM on May 04, 2018, 09:12:18 am
  Not with proper gluing technique and the right glue.
Title: Re: Deflexing a Stave
Post by: bushboy on May 04, 2018, 09:21:04 am
Very cool idea!love it when people try new things!I have been thinking about something similar.cutting a small v in the handle,use some heat to almost close the gap ,add glue and mechanically make the bond.maybe a thin veener over the joint would add some sercurity.just my thoughts?my crappy drawing!lol!
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 09:23:36 am
I think I may try something like what Pat mentioned. I've got an Ocean Spray stave with too much reflex. I think a "V" would cause too much localised pressure/stretching. All the stretch would be concentrated right opposite the point of the "V". I'm thinking much like Simk but with rounded corners. I guess a cross between Pat's and Simk's. Something that would give a little length to the bending section.
Title: Re: Deflexing a Stave
Post by: Bayou Ben on May 04, 2018, 09:29:58 am
I was thinking the same as PatM, but that's a cool idea and I'm sure it will still work that way. 
Title: Re: Deflexing a Stave
Post by: PEARL DRUMS on May 04, 2018, 10:05:00 am
That wont budge, it cant. Nice work.
Title: Re: Deflexing a Stave
Post by: sleek on May 04, 2018, 12:04:27 pm
That wont budge, it cant. Nice work.
Agreed, and I like the idea a lot. I wanna try something like that for reflexing.
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 12:56:55 pm
Here's my try so far. I used a hole saw and then joined the holes. I might have gotten a little close to the back but it sure bent easily. I'll be testing this on my shooting machine a bunch before I shoot it. Now to try and fit a piece in the hole ??? ???
Title: Re: Deflexing a Stave
Post by: simk on May 04, 2018, 02:18:37 pm
DC, The hole saw! That's it! I was already thinking about how to do as PatM suggested, didn't know how to cut a nice circle. Thanks.
With the next one I will use a slightly bigger radius but  only cut one piece out, so that I can reglue the original piece. Why did you do 2 cuts? Anyway I wouldn't worry about a failure with your bow - you can hang a car on this piece of wood. My first was much worse so that I definitly had to fix it with fiberglass. Yours must be still ok.
bushboy: I did this, but its enormous stress for the wood if you do just a v - it's not bending nice unless you go too deep, at least for memyselfandI The challenge is, to get it done so nice, that you don't need a handle wrap. Mine also looks a bit odd because I also dry heated for the bend, which wasn't a good idea and gave stronger outlines.
Now I got an ugly tillering-job to do on this  :BB
Cheers

Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 02:28:51 pm
If you use a single hole you will still be concentrating the stresses like the "V", not as much but still. With two holes you can see that I have the distance between red arrows to bend. I tend to over think things. I am having an awful time cutting the  patch though. I would suggest using a wood of contrasting colour to help hide the glue line. I'm using the same wood so my glue line will look kinda bad I think unless things pick up before I glue.
Title: Re: Deflexing a Stave
Post by: simk on May 04, 2018, 02:52:49 pm
with my magic wood one bigger hole will be good for that little bending  ;D - much better than that ridiculous v  8)
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 03:03:52 pm
You may get lucky and the kerf of the hole saw will allow you to use the piece/plug you cut out. Steam the bow, put the plug back in the hole and bend the bow around it to tighten it back up. I'm going to try that with mine but I still won't get a real nice glue line I don't think. I'll post a picture after I clamp it all up. Oh, timer went, steaming is done, time to clamp it up.
Title: Re: Deflexing a Stave
Post by: PatM on May 04, 2018, 03:14:54 pm
I just freehand an arc  between the high points of the fades and then rasp out the dip, Steam and bend across my knee.  Then finesse the surface and a piece to fit.  Doesn't take long to match them up.
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 03:17:38 pm
Here it is all clamped up. The wedges under the tips tighten the bow around the plug. The glue line may improve when everything springs back a bit but I'm not holding my breath. I'll leave it for a couple of days I think.
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 03:21:26 pm
I just freehand an arc  between the high points of the fades and then rasp out the dip, Steam and bend across my knee.  Then finesse the surface and a piece to fit.  Doesn't take long to match them up.
I just don't have that much finesse. If I try that I usually have to try 2 or 3 times. I got lucky this time. I don't have much more dry OS to make more plugs. Do you think you could get away with just about any wood in there or should it be the best compression wood you've got?
Title: Re: Deflexing a Stave
Post by: sleek on May 04, 2018, 03:25:32 pm
The only problem I see is tje bend will focus on the center of tje cut out, just like a bow thats a straight non tillered stick will bend only in the center. May need to find a way to actuall tiller out that gap, so its a nice smooth bend and not abrupt.
Title: Re: Deflexing a Stave
Post by: simk on May 04, 2018, 03:31:01 pm
DC: same same should be allright i think - i dont think the wood gets stressed to the limits in the handle section. i'm pleased to watch your immediate progress, i'm a slower worker. sleek: tillering the gap, a new discipline (lol). cheers
Title: Re: Deflexing a Stave
Post by: willie on May 04, 2018, 03:47:09 pm
another way to avoid all the bend in one place, of course for a bow handle one wouldn't need to go so deep
Title: Re: Deflexing a Stave
Post by: simk on May 04, 2018, 04:00:22 pm
evolution of mankind  :BB
Title: Re: Deflexing a Stave
Post by: DC on May 04, 2018, 05:08:15 pm
But then you would have to know someone who could calculate the angle of the wedges ;D ;D ;D. Too many glue joints I think, just asking for trouble.
Title: Re: Deflexing a Stave
Post by: TorstenT on June 05, 2018, 01:32:43 am
DC, your idea with the circular cutouts would be ideal for a setback (e.g. for a 5-curve), too!
You could cut it out, steam it and insert a slightly curved bigger block fitting into the gap. This way, the setback will keep its depth and the block can’t pop out.
Cool! Gotta try this for sure!  :)
Title: Re: Deflexing a Stave
Post by: PatM on June 05, 2018, 05:32:22 am
The thin spot in the center would need to bend too.  The transitions on the circular edges would almost surely separate under that backward bend.
Title: Re: Deflexing a Stave
Post by: DC on June 05, 2018, 11:02:14 am
It was a real bear to get the piece to fit even close. If you figure a way to get a nice fit please post it. I put another piece over the bottom to tie it together. When I did mine I could see that with decent glue lines and a contrasting wood it would make a very nice handle. A leather wrap handle solved my glue lines. :D :D
Title: Re: Deflexing a Stave
Post by: Eric Garza on December 21, 2018, 02:56:55 pm
If you are going to invest all that effort, why not just cut the stave into billets and make a spliced, deflexed handle?
Title: Re: Deflexing a Stave
Post by: DC on December 21, 2018, 04:02:55 pm
I think we were kind of looking for an easier way. Didn't really find it. :)
Title: Re: Deflexing a Stave
Post by: simk on December 21, 2018, 04:21:47 pm
Splicing anxiety  ;D never done that... and often i wouldn't shorten a stave
Title: Re: Deflexing a Stave
Post by: backtowood B2W on December 22, 2018, 02:53:11 am
Nice experiment !
To get a good fit, why not steam the handle and the plug and then squeeze together?
nice idea simk!
Title: Re: Deflexing a Stave
Post by: dratera on December 22, 2018, 06:56:30 am
DC, I have never tried this but to get a nice fit maybe take some kind of moldable hard clay, shove it in the gap, take it out and saw it to a thin slat, then put the slat on your plug wood and paint an outline
Title: Re: Deflexing a Stave
Post by: DC on December 22, 2018, 08:32:04 am
Nice experiment !
To get a good fit, why not steam the handle and the plug and then squeeze together?
nice idea simk!
I believe steam makes wood flexible across the grain but not along the grain so I don't think it would help the fit at the ends of the plug.
Title: Re: Deflexing a Stave
Post by: DC on December 22, 2018, 08:38:35 am
DC, I have never tried this but to get a nice fit maybe take some kind of moldable hard clay, shove it in the gap, take it out and saw it to a thin slat, then put the slat on your plug wood and paint an outline
You can really do the same thing just by tracing the gap on your plug wood. I think the problem I was having was just slight differences in the curves (maybe misalignment of the holesaw holes)  that makes one side of the plug a different shape than the other. Getting a plug that will "fit" is not hard, getting a good glue line all around is a PITA.