| From: kudu
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
I just finnished a real nice pair of take down limbs for my Bob Lee Recurve. Buttt, I missed my weight by about 11lbs too heavy. my total limb thickness is .215 and makes about 52# I would like to hit 41-43# .
1- what should I aim for on my next try .199-.200 thickness
2- dose it make any difference in glass thickness (I used two clear @.050) should I try a .050 and a.040? and then the wood lams?
Thanks Adam
|
|
| From: JamesV
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
B Jansen's lamb stack calculator says the stack thickness should be: .178 for 42#
James
|
|
| From: fdp
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
It does depend on whether reduce glass or wood. Also makes a difference in how the bow feels.
|
|
| From: kudu
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
JamesV I pluged in .215 @ 52# with a desired weight of 42# and got .200 New Lamb thikness. I see you have .178 where am I or you off?
I think Id like to try less glass to get a "softer" al'beit slower limb
hows this ? .050 glass back .040 glass belly and two lambs of .055 wood, hickory most likley
|
|
| From: Bowlim
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
If two bows have the same draw weight, but one has more wood, why would it be slower? It will be lighter. It won't be as tough, but so long as it is within norms for strength...
Wood type will mater. If you used more wood and it was more compressible, it might be slower due to high levels of deformation.
If all else was equal, the weight from a reduction to .200 should be 42. The Jensen calc might take more into account, like relative thickness of parts, never seen it.
The basic math is 200 cubed, divided by 215 cubed. Which is roughly .8. Multiply that by your current draw weight. Result is 42.
|
|
| From: Bowlim
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
178 would be 29.5#. That seems too huge to be attributable to the composition of the stack. The best info you have at the moment as to how that will come out is the limb you already built, assuming it was normal. If you do as little to change it as possible, you should come out closer than if you make a lot of proportional changes.
|
|
| From: fdp
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
The ratio of wood to glass in a bow limb determines the way the bow feels when you draw it as well as how the bow feels on the shot. In addition, there is a ratio of wood to glass that provides the best performance for a given range of draw weights.
|
|
| From: JamesV
|
|
|
|
|
|
|
| Date: 31-Mar-15 |
|
Adam................
I ran the numbers again on B Jansen's calculator and came up with the same number. If .215= 52# the calculator says .178983 will give you a 42# bow. Use the numbers you are comfortable with and be sure to let us know the results. We might all learn something here.
James
|
|
If you have already registered, please sign in now
For new registrations Click Here
|
|
|
|
