AVCase design Arvin bow build

[Selfbowman]

I am going to hit those measurements real real  close . Put it on a long string check it to 20” draw. But I suspect if I hit the measurements right it will be spot on at full draw. If not me and the engineer will have a sit down talk! 🤠🤠🤠

[bjrogg]

I am going to hit those measurements real real  close . Put it on a long string check it to 20” draw. But I suspect if I hit the measurements right it will be spot on at full draw. If not me and the engineer will have a sit down talk! 🤠🤠🤠

It’ll be interesting to see what the tiller looks like.

I would think if the numbers are right and both bows were made from clean wood, it should be pretty good.

Maybe a different in weight but a similar bend.

The numbers would have to be really good not to need a little fine tuning though.

 
Bjrogg

[Selfbowman]

Oh so this is real test for the engineer and old Arvin is what you are saying BJ. Now that I am about to try to hit those numbers I’m beginning to wonder what i got myself into!🤠🤠🤠🤠

[bradsmith2010]

variations in the wood,, could effect what the numbers do,,since all wood and staves vary,, but you should be close,,
but I wouldnt really know till I got it to full draw and shot it a bit,, the wood may settle in various ways,,and it may need a bit of fine tuning before full draw is a good idea,,will be interesting to see how it goes, thanks for posting,, also moisture content will effect how the stave reacts to bending,,
    do you know the mositure content of the bow you using the numbers from,,,

[mmattockx]

Ok guys Alan was nice enough to give me a design to build by and I was fortunate to have a real clean. Flat Osage stave. The design was close to my caul I normally use. The growth rings I don’t consider ideal but good and even in thickness. So. We will see how this turns out and how good I am at following the engineers drawings.🤠🤠

Very cool, Arvin. I look forward to seeing how it all works out. My limited experience with designing a bow and building to the design says it will be very close on the tiller and you will only have to fine tune the last few percentage points on the tree.


Mark

[Selfbowman]

Brad the meter is blinking 6% . The owner’s manual said this would of be below 5.5%

[bradsmith2010]

well it seems a little dry for osage,,maybe get some input from others,, just me,, I would put somewhere not so dry and sprits it or something,,, the stave the bow was measured from might not have been that dry,,just guessing,,its hard in winter things get so dry,, maybe start a thread,, is my stave too dry and see the response

[Selfbowman]

Well I got down to checking my numbers . Cut the  knocks in. Put it on the tree and I pulled th long string to where the tips came almost to brace . Seen area that needed more off. Well that’s where the fine tuning needed to happen on my numbers. I think we missed our weight of fifty pound draw weight. Just the way it feels at floor tiller maybe 40-45

[Selfbowman]

Now at fine tuning. I checked thickness at all spots of the limbs if off a hair I put one mark  . If two hairs needed to come off I put 2 marks. You get the program. Ok smart guys laugh! Guys this is real good for tuning your finger calipers. I know there is bowyers on this site that have real good finger calipers.

[Selfbowman]

Brad just stay tuned in. I’ve got some places that I need to add a hair.🤨🤠  this going to be a fun experiment. Engineer vs. Builder 🤠🤠

[bjrogg]

Brad just stay tuned in. I’ve got some places that I need to add a hair.🤨🤠  this going to be a fun experiment. Engineer vs. Builder 🤠🤠

This is interesting Arvin.

It definitely isn’t how I build a bow. I’m definitely not the building to measurements type.

I rarely measure anything more than the length and rough handle dimensions.

I often get asked for measurements. It seems like I work with so much character wood that doesn’t tend to follow the blueprints.

Be interesting to see if the really clean wood will

Bjrogg

[Selfbowman]

BJ your one of those finger calipers guys I was thinking of!

[bjrogg]

BJ your one of those finger calipers guys I was thinking of!

Yes I am.

Honestly I shouldn’t say I never measure anything because I constantly measure them. Just can’t put a number on it

Bjrogg

[mmattockx]

It definitely isn’t how I build a bow. I’m definitely not the building to measurements type.

I often get asked for measurements.

Be interesting to see if the really clean wood will

BJ, there is nothing wrong with doing it by eye and finger calipers. If you know what you are doing then it will get you a very good bow in the end. Your measurements only work for the wood you have, anyway. For the next piece the modulus of elasticity and strain limits will be different and require different dimensions.

So far I have found that straight grain boards do follow the design numbers very well. Your character wood will also follow the same laws of physics but it doesn't look like it because you have to work around knots, bends and other features that affect how it appears in the end even if the actual width and thickness is to the math.

One thing I have found from using software to do the design is it gets the bend so close to perfect right from the start that my tillering eye has improved when I look at one that isn't bending correctly. This was an unexpected benefit.


Mark

[bjrogg]

I agree Mark.

The character ones do follow the rules but it’s more of a find the right average of the numbers and my fingers just seem to be able to compute them automatically. Even though I can’t tell anyone what they are.

Bjrogg