Author Topic: is my project doomed from the start?  (Read 19166 times)

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Offline Zugul

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Re: is my project doomed from the start?
« Reply #30 on: August 12, 2024, 08:40:13 am »
I've gained 1 1/2 inches of draw and to me it seems like the inner half of both limbs is bending decently while the outher half is pretty stiff (left outer 1/2 limb stiffer then the right one). What do you guys think?




Offline Zugul

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Re: is my project doomed from the start?
« Reply #31 on: November 05, 2024, 07:24:16 am »
After a long pause I got at this bow again, now it's finally at low brace height. I also corrected the deflex between the knot and the end of the left limb, to make it easier to judge the bend there. To my eye the bow seems a bit stiff in the inner 1/3 of each limb and in the knot area, what do you guys think?




Offline superdav95

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Re: is my project doomed from the start?
« Reply #32 on: November 05, 2024, 09:42:10 am »
Yup that’s what I see too.  Looking good though.  Get it to brace and then get better idea on how the bend is coming from brace.  The bend draw will look different from brace. 
Sticks and stones and other poky stabby things.

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Offline Zugul

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Re: is my project doomed from the start?
« Reply #33 on: November 21, 2024, 11:32:51 am »
Finally managed to get the bow to a 5" brace height, after getting it to 35# at  a little more then 14" when it was at a shorter brace. It started getting a bit of set (1/2") pretty spread out along both limbs but there's a touch more of it at the wiggle on the right of the middle of the bow, so that area wil stay untouched. Other than that I'd say it can bend a touch more right in the middle, thoughts? After that adjustment I'd just keep getting the weight down while I approach draw lenght  :BB


Offline Zugul

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Re: is my project doomed from the start?
« Reply #34 on: November 24, 2024, 07:03:28 am »
I did a few little tweaks and brought the brace height up to 6", the weight is now at 35# at 16". Set did not increase so it seems like I'm on the right track, maybe the right limb is still a bit stiff around mid limb. From now it should be only a matter of adjusting the right limb and then even mass removal and frequent tiller checks, correct?
If you click on the image you'll be sent to the one I posted on flickr, where you can zoom on it if needed to better judge the bend



« Last Edit: November 24, 2024, 08:54:12 am by Zugul »

Offline Pappy

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Re: is my project doomed from the start?
« Reply #35 on: November 24, 2024, 09:24:11 am »
Looking really good to my eyes. Pappy
Clarksville,Tennessee
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Offline superdav95

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Re: is my project doomed from the start?
« Reply #36 on: November 24, 2024, 04:59:01 pm »
Me too
Sticks and stones and other poky stabby things.

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Offline Zugul

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Re: is my project doomed from the start?
« Reply #37 on: February 02, 2025, 04:04:54 pm »
So, I've tillered this bow a bit more, now it's 35# at around 19.5" of draw lenght. I tried something new to see if I'm on the right track: I've made a realistic model of my bow (for what I could) on VirtualBow and then I "tillered" the virtual version to get an even distribution of stress across the bow, maintaining the front profile and changing only the thickness of the limbs. My reasoning is that, for a ceartain front profile, there's only one particular shape (tiller) the bow can have to spread the load evenly across the limbs, wich should minimize set. Feel free to correct me if I'm wrong, I still consider myself a complete newbie! :BB Here are pictures of the bow and the model from VirtualBow at the same brace height and draw lenght.










« Last Edit: February 02, 2025, 04:09:58 pm by Zugul »

Offline Pappy

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Re: is my project doomed from the start?
« Reply #38 on: February 02, 2025, 08:43:53 pm »
Still looking really good to me.  :)
 Pappy
Clarksville,Tennessee
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Offline bjrogg

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Re: is my project doomed from the start?
« Reply #39 on: February 02, 2025, 09:44:14 pm »
Whatever you are doing it looks really good to me so far and it seems like your unbraced profile is holding its shape well.



Bjrogg
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Offline JW_Halverson

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Re: is my project doomed from the start?
« Reply #40 on: February 03, 2025, 12:48:32 am »
So, I've tillered this bow a bit more, now it's 35# at around 19.5" of draw lenght. I tried something new to see if I'm on the right track: I've made a realistic model of my bow (for what I could) on VirtualBow and then I "tillered" the virtual version to get an even distribution of stress across the bow, maintaining the front profile and changing only the thickness of the limbs. My reasoning is that, for a ceartain front profile, there's only one particular shape (tiller) the bow can have to spread the load evenly across the limbs, wich should minimize set. Feel free to correct me if I'm wrong, I still consider myself a complete newbie! :BB Here are pictures of the bow and the model from VirtualBow at the same brace height and draw lenght.











Glad to see you back and still working on this bow. I think it has real potentional to be a bow that works for you!
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline willie

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Re: is my project doomed from the start?
« Reply #41 on: February 03, 2025, 01:11:03 am »
Whatever you are doing it looks really good to me so far and it seems like your unbraced profile is holding its shape well.
Bjrogg

agreed, and looks like you have that knot area neither to stiff or weak which can be tricky

Quote
for a ceartain front profile, there's only one particular shape (tiller) the bow can have to spread the load evenly across the limbs, wich should minimize set.

very true. and the best approach since you are concerned with getting 40# out of a short and narrow stave.
when width and length allow, having a stiffer (lesser stressed) handle area and tips can improve performance and feel (dampness) in the hand.

Offline Zugul

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Re: is my project doomed from the start?
« Reply #42 on: February 07, 2025, 05:47:40 am »
Still looking really good to me.  :)
 Pappy
thaks, it's really heartening to hear it!
Whatever you are doing it looks really good to me so far and it seems like your unbraced profile is holding its shape well.
Bjrogg
It did take a bit of set, around 1/2" for now, but I'm fine with it considering the sub-optimal design I chose
Glad to see you back and still working on this bow. I think it has real potentional to be a bow that works for you!
Thanks! I hope this piece of wood thinks the same!  ;D
Whatever you are doing it looks really good to me so far and it seems like your unbraced profile is holding its shape well.
Bjrogg

agreed, and looks like you have that knot area neither to stiff or weak which can be tricky

Quote
for a ceartain front profile, there's only one particular shape (tiller) the bow can have to spread the load evenly across the limbs, wich should minimize set.

very true. and the best approach since you are concerned with getting 40# out of a short and narrow stave.
when width and length allow, having a stiffer (lesser stressed) handle area and tips can improve performance and feel (dampness) in the hand.

I'd say the knot area is still a tad stiff, but I don't want to weaken it too much... I'll keep a close eye on it while tillering. Since a bit of set already happened I dropped my target weight to 35# and even if I come a couple of pounds uderweight I won't be mad as long as I get a functional bow. For my next project I already have a much longer and wider floor tillered stave waiting on wich I'll try to leave those areas stiffer.

I did not make any progress with the tillering process yet but I took off the tip overlays since they were made out of a not strong enough wood (Sorbus torminalis, wild service tree) wich was getting dough into by the string and made new ones from heat treated black locust, wich should be strong enough and should look good. I hope to finish up the tip overlays this afternoon and then get back at tillering in the weekend. Thanks to all of you for the kind replies!

Offline Zugul

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Re: is my project doomed from the start?
« Reply #43 on: February 08, 2025, 01:56:12 pm »
just a quick update on the tip overlays: I sanded smooth one of them up to 280 grit and then burnished half of it, this is the result. It's still unfinished but I'll get to it when the bow is complete.

I think it looks pretty neat!