Increasing width

[DC]

I want to make a 50# copy of a 40# bow. I want to do it with width increase only. So is it straight forward increase the working limb 20% in width? No magic or secrets? Tips and statics can stay much the same?

[mmattockx]

I think that is correct, but you need to add 25% to the limb width to get to 50#.

50/40 = 1.25


Mark

[DC]

Right

[bradsmith2010]

ok what is the width now, and what will the 25% increase make it,,

[DC]

It's 1.25" just out of the fades so if I multiply by 1.25 it comes to just over 1.56". I think that's right. Percentages confuse me, it's different going up or down I think.

[sleek]

That should work DC. Its how I do it.

[mmattockx]

It's 1.25" just out of the fades so if I multiply by 1.25 it comes to just over 1.56". I think that's right. Percentages confuse me, it's different going up or down I think.

That is correct. I find fractions are often easier to use than using the percentages when scaling dimensions/properties. You put what you have on the bottom and what you want on the top and multiply by the dimension you want to scale.

(50/40) x 1.25 = 1.5625


Mark

[Hawkdancer]

Y'all have a lot more experience than I do, but I would probably round up to 1 3/4" to have a screw up factor - oops!, I mean a margin of error.  The wood very likely does not know decimals and/or fractions !
Hawkdancer

[DC]

My belly is bordering on thin so I think I will make it 1 3/4 and side tiller it until I'm happy.

[sleek]

My belly is bordering on thin so I think I will make it 1 3/4 and side tiller it until I'm happy.

How thin is it?

[DC]

It's right around 7/16" at it's thickest. If it was 1 1/4" wide it would be right around 40# so I'm very close. I just want to hedge my bet. Just a little waggle with the band saw and I have to rethink everything. I can thicken the boo a touch but I'd rather keep it thinner for a little less weight.

[mmattockx]

Y'all have a lot more experience than I do, but I would probably round up to 1 3/4" to have a screw up factor - oops!, I mean a margin of error.  The wood very likely does not know decimals and/or fractions !
Hawkdancer

Wise words, leaving an extra margin is always a good idea. Not only does the wood not know fractions, this also assumes the two pieces of wood have very close to identical material properties. We all know how that works out some days.

Just a little waggle with the band saw and I have to rethink everything.

It's like you have been in my shop watching me cut things... I try to leave a fair margin with the bandsaw and rasp to the line, my hand isn't steady enough while free handing cuts to be sure of where the kerf will end up.


Mark

[DC]

Just the other day I was congratulating myself for being able to follow a line. What is it, "Pride goeth before a fall". I think what it is is that the better you get, the more you push the boundaries.

[Hawkdancer]

We get too soon older and too late smarter?!  I plan to do quite a bit of practicing with the new bandsaw before I cut close to the line!luckily, I have some pieces of wood that will allow for that!  Also have to keep the fingers on the hands !
Hawkdancer

[DC]

My first rule of using a saw of any kind is take a close look at the teeth. Imagine them ripping through your fingers. OK, now proceed with the cut.