Advice please, Take-down in process-experiment over

[KS51]

Darksoul,

I think you are right that the ends need to be thicker in my next attempt.  I will also be making the limb a bit longer (and the handle a bit shorter)  so that the overall geometry lends itself to the drawlength I'm after.

I did score some Ipe for the next try, and now that I've gotten as far as I did on this one, I have a lot more confidence in the strength of the bolts than I did going into it.  (Engineering calcs are all fine and good, but until you test it, it doesn't matter)

That piece of Oak was an exceptional piece I had left over from a few years ago.  It had an SG of around .68 and some of the biggest late growth in the rings I've ever seen.  The next one is with Ipe, so that should  remove that potential issue.

Steve,  I agree that the radius vs thickness is just a matter of the %.  But I come at this as an engineer and generally try to do some calcs at the front end.  I come at it from the radius because this is easier for me to do the math.  It all works out to the strain-stress relationship.

Ken

[Badger]

Ken, if you come at it as an engineer then you  will need to figure the strain on the wood based on the radius it is bending and the thickness. Most wood has less than 1% elasticity.

[missilemaster]

Here's how I drilled the alignment pin in my T.D.  I got all my hardware from bingham. First, I  marked out the center line on my riser pads and drilled and tapped it for the threaded insert and drilled a 1/4" hole half the depth of my alignment pin(I kept it about 3/8" away from the end of the riser). 

   Next, after i have epoxied in the threaded insert and put the alignment pin in the riser, I mark out center on the limb pads and drill for the limb bolts (but not the alignment pins).

  Screw in the limbs till the alignment pin in the riser is just touching the the limb pad. Put it in a vise so you can look down the limbs and verify everything is lined up.

   after its lined up, take a clamp and squeeze the limb pad just enough that the alignment pin leaves an indentation on the limb. then drill just enough that the top half of the pin bottoms out. Doing it this way will mean that you wont have the alignment hole showing on the top of your limb.