Author Topic: 59" HopHornbeam Reflex-Deflex Self Bow  (Read 895 times)

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Offline Don W

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59" HopHornbeam Reflex-Deflex Self Bow
« on: August 23, 2021, 11:23:54 am »
59" HopHornbeam Reflex-Deflex Self Bow


60#@28"
Tip to tip itís 59 1/4″
the limbs are 1 1/4″ wide at the widest and are somewhat parallel to about quarter limb.
the limbs are about .70″ thick off the fades to the center of the crown
the tips at the nock are about 1/4″ wide
stained with Fiebingís Leather Dye  in a camo type style with red and dark brown stain
arrow rest is whitetail antler
The belly was heat treated using the heat gun.
As I was heat treating it, it was clamped to a reflex deflex form (see photos)
Finished weight (with handle leather and string) 18.4oz

I don't usually shot a 60# bow, but this seems to draw easier. (**comments on why this might be**)

This is the second half of the log from http://www.primitivearcher.com/smf/index.php/topic,70443.msg989400.html#msg989400  It's marked stave 2 for my reference. Or on my web site https://www.diy.timetestedtools.net/62-hophornbeam-stiff-tipped-flatbow/

It's not a super fast bow but still shoots my 650 gram arrows in the high 130fps range. Certainly good enough for white tail
















I post here for the constructive criticisms, so hit me with it! At my age i need the accelerated learning plan!
Don

Offline Pat B

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #1 on: August 23, 2021, 12:07:06 pm »
My only suggestion would be to allow the tips to be ahead of the handle unbraced but having that much reflex is probably why it draws smoothly. It's all give and take.
I think you are getting the hang of this wood bow building stuff, Don. You seem to be a quick study.  :OK
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline sleek

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #2 on: August 23, 2021, 05:59:49 pm »
Your draw is easier due to lower string tension at brace. This is caused by your bow being over all, deflexed. There is nothing wrong with that and they make nice shooting bows. But, the low early draw tension is the reason for your low arrow speed. As you make more of these, make each one with the tips half an inch further back until you start taking set. That will be the max stress and speed that bow design can handle at that width. If you want to move the tips further,  make the bow half an inch wider and continue putting the tips an inch further back until you get set. If done right you could easily add 50 fps to your bow within 5 or 6 bows.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline bownarra

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #3 on: August 24, 2021, 03:39:52 am »
Yes as mentioned above the overall deflex is the reason for the speed and ease of draw.
Your form added too muc hdeflex and/or not enough reflex. A good place to start tillering is to have the tips 1 - 2" reflexed/in front of the handle. Once the bow is tillered you should hopefully end up with a near straight bow. This will mean you have higher string tension at brace and the bow will then store a lot more energy.
Deflexed bows have their place but it would generally be a design to use on a low quality wood. Hophornbeam is premier wood and will take quite a lot!

Offline simson

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #4 on: August 24, 2021, 05:38:02 am »
+1, as mentioned above. You've got already good advice.
You used the same caul as for the other 62ď long bow. As this one is shorter the effect of too much deflex or too low reflex is much more obvious.
You should make another caul, so that your tips are laying in front of the handle not behind. Better and much easier is to work with two cauls, one for each limb. Gives much better control and time. Steam the limbs, then heat treat on caul if you like.
IĎm not sure how your form looks really, as the camera shows it in an angle. Make sure that the reflex curve have an increasing tendency.
Another tip: Note the reflex after the steaming/heat treating, I call it initial reflex. Compare the number with the remaining reflex after tillereing and then after shooting in, I call it netto reflex.
Of course the aim is to keep the difference as low as possible. Watch where you lost the reflex.
This is just my opinion, no harm, Just want to help!
Simon
Bavaria, Germany

Offline Don W

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #5 on: August 24, 2021, 07:52:42 am »
I appreciate the help and will definitely be trying out the suggestions.
Don

Offline neuse

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #6 on: August 31, 2021, 06:55:52 am »
Love coming here to always learn something new.

Offline superdav95

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Re: 59" HopHornbeam Reflex-Deflex Self Bow
« Reply #7 on: August 31, 2021, 10:28:17 am »
Some good advise there.   Iím gonna use the 2 cauls method on my next bow I think.  Bow looks well tillered to my eye Don.  Keep it up!