Author Topic: is my project doomed from the start?  (Read 18565 times)

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Offline Selfbowman

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Re: is my project doomed from the start?
« Reply #15 on: December 20, 2023, 10:02:45 am »
When did the long crack happen on the knot. The wood is to wet. Let it set a couple weeks or  so and wrap both sides of that knot with rawhide when you get the bow drawn to about 20” and close to target weight. Wrap it. And my 67” bows 40@28 is 24-26 #t 20”.  50@28 is 38-40@20. You can probably get any bow of  that length an weigh it and get a reference on the 20” weight rule. This is where set happens for me . That will give you an idea so you can rawhide early.. just a suggestion. Good luck with the build.
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Offline superdav95

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Re: is my project doomed from the start?
« Reply #16 on: December 20, 2023, 11:44:16 am »
In your last pic posted you show the knot cluster.  It looks to me in the pic that you have left enough meat around that knot but it looks like you may have some grain run out on the right side of it.  My suggestion on this knot is to have little to no grain run off here.  I would make every effort to strictly keep to the grain lines around this sucker.  Even if it looks a little weird and you get the urge to narrow it intuitively to match the width of the other limb don’t do it.  Leave it with equal measure of wood on both sides of this knot but keep to zero grain run at this location.  You can always slowly and increments of narrowing up away from this cluster to get to where you want.   I agree with what others have said here too with that it’s a shorter bow to achieve to draw length and weight you are looking for but it is doable.  Especially if bendy thru handle bow.  This means every part of this bow is working so that is also why it’s crucial that that knot is got no run off there.  You basically want the wood around that knot to support the bend stresses alone and should be able to drill out that knot and still have it bend good.  Not that I’m suggesting you drill it out but my point I’m trying to make is that you need to work that knot as if it it doing the work on it own and not relying on any help from that cluster.  Anyway that’s my opinion of what I’d do with the knot.  It would give some neat character too.  As far as the twist I may just get it bending to about 20” first following all of the dips and valleys belly to back for good consistency of thickness.  Use your finger calipers as bjorn says!  I think your in good shape so long as you give attention to those crucial areas of potential problems areas.  Get to 20” draw then maybe worry about any twist corrections.  Imho best of luck on it. 
Sticks and stones and other poky stabby things.

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Online Zugul

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Re: is my project doomed from the start?
« Reply #17 on: December 20, 2023, 02:25:43 pm »
When did the long crack happen on the knot. The wood is to wet. Let it set a couple weeks or  so and wrap both sides of that knot with rawhide when you get the bow drawn to about 20” and close to target weight. Wrap it. And my 67” bows 40@28 is 24-26 #t 20”.  50@28 is 38-40@20. You can probably get any bow of  that length an weigh it and get a reference on the 20” weight rule. This is where set happens for me . That will give you an idea so you can rawhide early.. just a suggestion. Good luck with the build.

There are no cracks in that area, the dark line is simply a pencil line I drew to help me establish the centre of the limb lenght-wise. I've kept the stave in a spot where I normally measure 66-72°F and 40-50% RH until it stopped loosing weght (2 weeks ago) so I'm pretty confident it should have around 8-9% humidity left in it. Thanks for the references of draw weight - draw lenght, they will come in handy as soon as I start tillering!

In your last pic posted you show the knot cluster.  It looks to me in the pic that you have left enough meat around that knot but it looks like you may have some grain run out on the right side of it.  My suggestion on this knot is to have little to no grain run off here.  I would make every effort to strictly keep to the grain lines around this sucker.  Even if it looks a little weird and you get the urge to narrow it intuitively to match the width of the other limb don’t do it.  Leave it with equal measure of wood on both sides of this knot but keep to zero grain run at this location.  You can always slowly and increments of narrowing up away from this cluster to get to where you want.   I agree with what others have said here too with that it’s a shorter bow to achieve to draw length and weight you are looking for but it is doable.  Especially if bendy thru handle bow.  This means every part of this bow is working so that is also why it’s crucial that that knot is got no run off there.  You basically want the wood around that knot to support the bend stresses alone and should be able to drill out that knot and still have it bend good.  Not that I’m suggesting you drill it out but my point I’m trying to make is that you need to work that knot as if it it doing the work on it own and not relying on any help from that cluster.  Anyway that’s my opinion of what I’d do with the knot.  It would give some neat character too.  As far as the twist I may just get it bending to about 20” first following all of the dips and valleys belly to back for good consistency of thickness.  Use your finger calipers as bjorn says!  I think your in good shape so long as you give attention to those crucial areas of potential problems areas.  Get to 20” draw then maybe worry about any twist corrections.  Imho best of luck on it. 

At the moment there is a bit of grain runoff on one side of the knot, the one where I've left a bit more wood. Should I keep it wider or thin it? From what I understand now about working around the knot, I should simply have the limb as wide as it should be by design in that spot plus the with of the knot itself, correct? About the alignment, I'm correcting it now because before I started the string line was laying about 1 1/2" outside the handle, so it would have been pretty much impossible to start flexing the bow without it twisting on the tillering tree.

thanks everyone for your advice, I'm pretty slow and full of insecurities when I learn something new!  ;D

Online Zugul

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Re: is my project doomed from the start?
« Reply #18 on: December 20, 2023, 05:51:36 pm »
here some pics of where I'm at now: the "bow" is pretty much straight now, the string line tracks just 1/4" off the centre line in the handle.




 I'd say I can start removing wood in the next days, to make sure the thickness taper is even and also to let the stave rehydrate properly before starting the proper tillering process, going as slow as I can  O:)

Offline superdav95

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Re: is my project doomed from the start?
« Reply #19 on: December 20, 2023, 05:58:05 pm »
No problem we are all learning here.  Like others have already said. Take it slow.  As for the wood around the knot I think your approach will work too but what I’ve done in the past is measure the width of the same spot along the other limb and equally split that width on both side of your big knot cluster.  This depends too on the condition of your knots too. If solid and not just punky dead cluster of knots then doing this way errors on side of caution.  Your approach is similar.  As far as your twist I see what your saying.  I would do the same if it was off this much. 
Sticks and stones and other poky stabby things.

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Online Zugul

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Re: is my project doomed from the start?
« Reply #20 on: December 20, 2023, 07:13:51 pm »
just a question, where do you normally measure the width of a knot? because this one is very small on the belly side (1/4") but becomes a lot bigger on the back of the stave ( 3/4"). So if I leave the right amount of wood around it on the belly I'm pretty narrow on the back, the other way around if I follow the width on the back I'm probably over compensating on the belly. I hope I explained it properly  :P

Offline SLIMBOB

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Re: is my project doomed from the start?
« Reply #21 on: December 20, 2023, 11:42:45 pm »
The back.  You need the extra width to protect the back.  The extra wood on the belly will simply be made thinner so it will bend.
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Offline M2A

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Re: is my project doomed from the start?
« Reply #22 on: December 21, 2023, 08:20:40 am »
looking good so far. 1/4 off center should work well for you. I always try and keep string alignment closer to arrow pass side. you could even cheat the nocks over to get a little closer depending on what you want, still need arrows spined well. If you follow the grain around that knot it should give you the width of good material you need(maybe too simple of a statement....) draw with a pencil first and have a look and measure, but I like what Slimbob advice is. Good luck!
Mike       

Online Zugul

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Re: is my project doomed from the start?
« Reply #23 on: June 22, 2024, 01:04:57 pm »
so, after a very long time I've started working again on this bow. First of all I took off the string nocks I made, since I could not make the tillering string stay in place securely. I've opted for simple wood tip overlays instead, wich I'll leave roughed out until the bow is pretty much complete. After that I sanded down all corners and I used a caliper to make sure there were no thick spots on the limbs. Lastly I used a straight edge to mark a line on one side of the bow, from the center out to both tips. This way I can see better what areas are bending more then the others, simply watching how the line is bending. Here is where i'm at now, 35# at 3". All advice are welcome!



3" draw lenght, I've added the straight green lines to make it easier to see the bend.


if you click on the pictures you can see them on flickr and there you can zoom on them to see the line better  ;)
« Last Edit: June 22, 2024, 07:30:52 pm by Zugul »

Offline Jake Spoon

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Re: is my project doomed from the start?
« Reply #24 on: June 22, 2024, 03:12:45 pm »
Following this thread. Best of luck to you with it!!

Offline Aksel

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Re: is my project doomed from the start?
« Reply #25 on: June 22, 2024, 04:21:59 pm »
Be careful with the outer half on left limb - between the nock and the knot. Could be an illusion but it looks like its the weakest there. Reduce weight elsewhere especially on right limb.

Risk is you leave the knot too stiff and that it cases frets elsewhere when the wood tries to compensate..

go slow and enjoy!

Stoneagebows

Online Zugul

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Re: is my project doomed from the start?
« Reply #26 on: June 22, 2024, 05:04:50 pm »
I agree, it seems week there... but the line is not bending that much more then anywhere else. I'll leave that spot alone for now. I'll thin a bit where the knot is, very carefully since that could easily become a weak spot if I don't go slow enough.

Online Zugul

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Re: is my project doomed from the start?
« Reply #27 on: June 28, 2024, 08:36:24 am »
so, I made a little bit of progress on this bow. I'm pretty sure I was drawing a bit over my target weight in the pictures above, since after at least 60 scrapes with a card scraper on the entire bow I'm still al 35# at 3"... Luckily the stave didn't take any set and didn't fret, so I'm positive about it managing to hit target weight if I do my part correctly. Now the measurements are:
max thickness: 21 mm (53/64"), middle point of the bow
min thickness: 14 mm (9/16"), 4" from each end of the bow (I've decided to leave only the last 4" of each limb stiff, to gain a little more draw lenght)
phisical weight: 526 g (18 1/2 oz.)

from what I understand at the end the max and min thicknesses should be around 3/4" (19 mm) and 1/2" (13 mm), so from now on the weight should drop pretty fast.
As always, if I say something wrong feel free to correct me, since I'm here to learn  ;)
« Last Edit: June 28, 2024, 09:13:42 am by Zugul »

Offline superdav95

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Re: is my project doomed from the start?
« Reply #28 on: June 28, 2024, 11:21:37 am »
looking good. keep us posted. 
Sticks and stones and other poky stabby things.

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Online Zugul

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Re: is my project doomed from the start?
« Reply #29 on: July 03, 2024, 11:35:17 am »
making very slow progress, I'm at 35# at 4". I'd say it's bending pretty evenly, but I'll wait for advice from someone more experienced.
click on the pictures to see them on flickr if you want to zoom on them