Primitive Archer
Main Discussion Area => Bows => Flight Bows => Topic started by: Del the cat on February 07, 2015, 05:15:32 am
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Be gentle with me guys as this is a lot of firsts and highly experimental with a few erroneous assumptions thrown in.
I decided to try a Hazel flight bow modelled roughly on a nice Hazel bow I'd made ages ago.
Mistake 1. I thought the Hazel bow was 35# when it was 30# at 28".
Mistake 2. I thought it was vaguely symmetrical, but it turns out the lower limb is a couple of inches longer! (but it shoots like a dream)
The game plan was to draw the limb shape of the straight Hazel bow at FD, brace and unbraced and the make the flight bow with that FD curve as reflex at unbraced, and straight limbed at FD :laugh:
Well we all know how plans turn out ::)
The limbs were made individually from rapid seasoned (read "impatient old git") Hazel and first mounted in a rough try out riser block. I then drew up a better riser and made it up from some Mahogany planking. I like the way the limbs sort of splice into the riser. I used the trick from PA (Pearlie's trick?) of pegging with a wooden skewer to hold 'em in alignment while glueing/binding/clamping.
The limbs have untouched backs. Yes I did my pet trick of leaving the bark on so I could scare my self witless when it went CRACK and popped off ;D
Most of the recurve pulled out despite some heat treating, so there is little stored energy at brace. However I must have got some geometry about right as the tip deflection is similar to the first bow... well I s'pose it's bound to be innit? It's a bow... (slaps furry head with paw).
I ended up with 35# at 27" which is pretty much what I was after, mind I need to check on how we measure such things when it has an arrow shelf.
Anyhow the chrono' would be the judge.
First two shots were a bit tentative and I'd built up the nocking point a bit tight...
151 fps
152.4 fps ok but no cigar.
The whipping round the nocking point came off giving a looser fit, and I let loose with a slash/flash draw.... Wow! :o
172.2fps better check it's not a miss-read
164.6
164.5
What I really noticed is how much cleaner and consistent the readings were compared to a longbow where the arrow does the snake dance as it leaves the bow :laugh:
I haven't got a decent 'in the hand' FD pic yet, I'll post one if I get one later.
Seems like a pretty respectable speed for a bit of Hazel... ?
All comments, comparisons, suggestions and witticisms welcomed.
Oh yes the arrows were about 350gn
I could claim the fancy layer of Elm between the Hazel and the horn at the nocks is an artistic flourish or a cunning interface layer for superior glueing... but it's really cos, by the time I'd narrowed the tips with their temporary Elm nocks, the string a whisker too long ::). So by not rasping off the entire temporary nock I could gain about 1/4" at each end.
Del
Video of the nearly finished bow flexing on the tiller, here:-
http://bowyersdiary.blogspot.co.uk/2015/02/hazel-flight-bow-nearly-there.html (http://bowyersdiary.blogspot.co.uk/2015/02/hazel-flight-bow-nearly-there.html)
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Hey, thats a nice bow, well done with a great speed.
Again: design outperforms lbs!
Michael
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Thats good with that arrow weight. Are you going to test it for flite with some little fite arrows?
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Thats good with that arrow weight. Are you going to test it for flite with some little fite arrows?
Cheers.
Yup, I'm trying to turn up a little brass point on my small lathe, but it's not my field of expertise so I'm not making the best job of it. It's for my best flight arrow... I made the mistake of shooting it through the chrono ages ago... it went straight through the arrow stop netting and the point snapped off >:(
There's very little to chuck it onto... s'pose I could drill up the back end, epoxy it onto a mandrel and then turn the point and heat it off when it's done :))
I have a few other odds n ends of flight arrows, so I'll try to get out tomorrow and try it... only have about 240 yards, but that should be plenty.
Del
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I really like the 35# flight class. You can make some cool little bows.
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Woo.. just finished my flight arrow with shiny brass point 152.3gn WHOOPS TYPO it was 252.3 gn :-[.
192.0
187.6
196.1 fps
I gotta fess up, the arrow is actually 28" to the tip, but I don't think I fully drew it, trying not to over stress the bow.
I'm well chuffed with that :laugh:
Del
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Del,
It must feel good to have your favorite flight arrow back in action again. When you make the point, do you make it so it fits over the end of the arrow, or do you create a tang that fits into a hole drilled into the end of the arrow shaft?
That's a nice bow too. Did you really add an extra lamination so the bow will fit the string? Ha! You must really dislike making strings!
Alan
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Del,
It must feel good to have your favorite flight arrow back in action again. When you make the point, do you make it so it fits over the end of the arrow, or do you create a tang that fits into a hole drilled into the end of the arrow shaft?
That's a nice bow too. Did you really add an extra lamination so the bow will fit the string? Ha! You must really dislike making strings!
Alan
I turned a litte stub about 4.5mm diameter and similar length on to the end of the arrow shaft. The brass has a 4.5 mm hole drilled in the end to glue onto the stub. The hard bit is holding the tiny arrow head in the lathe chuck.
The extra lamination is just the remnant of the temporary nock overlay. Rather than rasping it all aoff and gluing on the horn, I left a layer which gave me a little extra wood to play with.
I don't mind making strings too much, but I hate the waste, and I have bunches of strings hanging up... but never one the right size (ok... well sometimes I find one the right size ;D)
Del
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I don't know squat about flight bows or speed, but that's a pretty piece of work Del
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I don't know squat about flight bows or speed, but that's a pretty piece of work Del
Cheers.
Just tried it for distance, only managed 193 yards. The laser rangefinder worked well by standing by the arrow and sighting back to a piece of thin steel plate (off the back of an old electric oven) which I'd propped up on the shooting line.
Del
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Nice Del. I don't see where you made mention of the length but it does look pretty short. It's hard to retain some reflex on short bows. You need a high quality piece of wood that heat-treats well. You need 2 to 3 inches of reflex to give those light arrows a good push at the end of the stroke. If you can replicate that design using some good Elm you might see a big improvement in speed
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Mark, not sure if you shoot for distance or not but I am curious what weight arrows you have best luck with. If Dels arrow was going around 190 fps he had enough speed to travel about 260 yards or even slightly more. I believe his arrow pooped out on him because it was too light.
None of the fast flight bows I build for very light arrows ever do that well, my best distance bows are always much slower bows that seem to give me better arrow flight. I am going to try moving up to about 250 grains next year and see if it helps.
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@ Marc. Cheers, yeah, I didn't expect too much from hazel, just curious to see what it would do and try out that sort of shape.
@ Badger... I didn't get a very clean loose and was maybe a bit high with the shot, I was expecting it to go a bit further tho :(
Still it's all a learning experience, and I was pleased with the range finder.
That's what I love about this forum. I can talk to guys who really know their stuff.
A bit embarrassing really, I wasn't measuring to the drop off of the shelf so the draw length and weight weren't what I was after.
I've taken a load off the belly, and now got it to a genuine 28" draw at about 32#.
Now I'll try and get some of the heat treating and reflex back into that sucker.
At least I have a line in the sand to compare results :)
That's what I like about this stuff, the more you know, the more you realise you don't know :laugh:
Thanks for the feed back guys. When I've finished it, I'll shoot an arrow across the pond to you... ok maybe that's a tad optimistic :laugh:
Del
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Just let us know when its coming so I can catch it and send it back!!
Nice bow Del
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Del, can we get a few details? Bow length, handle/limb lengths, gluing area, glue type?
Thanks
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Mark, not sure if you shoot for distance or not but I am curious what weight arrows you have best luck with. If Dels arrow was going around 190 fps he had enough speed to travel about 260 yards or even slightly more. I believe his arrow pooped out on him because it was too light.
None of the fast flight bows I build for very light arrows ever do that well, my best distance bows are always much slower bows that seem to give me better arrow flight. I am going to try moving up to about 250 grains next year and see if it helps.
I haven't done any distance shooting in many years Steve, I don't have the place for it anymore, but I always found arrows around 250 to 275 grains to shoot the best, this is with bows of around 50#.
P.S. I bought a carbon arrow years ago to test for flight, re-fletched it with small feathers, and it wouldn't shoot any farther than my wood arrows
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Del, can we get a few details? Bow length, handle/limb lengths, gluing area, glue type?
Thanks
I'll add some details later... at work now.. >:(
Off the top of my head, the limb length is 27" from nock to riser. Riser length is 15", limbs deflexed at about 15 degrees.
Glue area 1.75" x 3.3" Resintite glue. The limbs are sort of keyed into the riser with a sort of V
ERRATTA... WHOOPS I MISSTYPED THE WEIGHT OF THE FLIGHT ARROW, I'LL RE-WEIGH IT WHEN I GET HOME :-[. (I blame my age ;))
any how, the bow has been re-worked now.
Del
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I've tried out the re-worked bow. Now a real 35# at 28" (or near as dammit)
207.1 fps
185.5
183.1
189.0
I think I'm at the limit of the Hazel, dunno if that first shot just put the set back into it, but it's pretty much back where it was before being re-worked.
I'll give it another try for distance when a chance presents itself.
I can't really hand on heart say I'm over the 200fps barrier, although I doubtless got the 100# Elm warbow over it when I shot 302 yards... dare not shoot it through the chrono for fear of destroying it.
Still it's given me a feel for the geometry...
Del
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Thanks Del :D
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Del- can you show us a picture of your arrow?
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Del- can you show us a picture of your arrow?
Here ya go.
The shaft is 5/16 tapered at either end. The point isn't as nicely blended in as the origal one was (but that one got lost)
This post on my blog shows a simple flight shaper, cut out of brass sheet, heat it up and push it over the rough shaped flight.
Really simple and works a treat :)
The nock is reinforced with a strip of waterbuffalo horn as it's been shot from much heavier bows. It also allows a nice slim nock.
http://bowyersdiary.blogspot.co.uk/2014/05/curved-profile-feather-shaper.html (http://bowyersdiary.blogspot.co.uk/2014/05/curved-profile-feather-shaper.html)
Del
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Very nice
Thanks Del