Good job. It will be interesting to follow your progress with this method.
Thanks. Next up will be some lam bows using Perry reflex and designed using the spreadsheet as well. I found a really nice straight grained red oak board the last time through home depot that I am going to cut into lams and glue into deflex and then reflex on forms.
One thing to note is that you have to do a bend test to get the MOE for the piece of wood you are using in order for the calculations to be accurate. Now that I have done one this way I will be a bit smarter the next time up. The way this one went I cut a sample piece from the board and did the test, which got me a good estimate for MOE (+/- 5% or so). Then I measured the draw weight at 20" and compared that to the predicted weight and adjusted the MOE in the spreadsheet until the two matched and I finished working the bow down to size with the updated MOE in the calculations. Next time I will start looking at the draw weight earlier and use that to adjust the inputs to the sheet before I have pulled it so far on the tree.
I've had to patch up a lot of bows that I messed up tillering and although they shoot fine the finished bow doesn't give me that warm fuzzy feeling that an unpatched bow does.
Considering how many things tried to go wrong on this one I figure it is a small miracle it survived at all. I think I went a bit thin on the patch and am concerned the hinge will eventually cause a failure there. So far it has survived 400+ shots with no sign of failure, but I still don't trust it. Next time I do a patch I will use the belt sander and remove more wood before patching it.
Did the set come in as predicted with the calculation?
To be honest, I screwed around with it so much in removing the backing and heating in reflex (that promptly pulled out...) and the hinge that I can't say. The board had a bit of deflex that warped in while it sat in my shop and then I reflexed it a bit and didn't keep really good track of where the tips were throughout, so I don't know where to start measuring from. Currently it has about 7/8" of permanent set on the upper limb (measured from straight) and a bit less on the lower limb. After unbracing it shows about 3/8" more set on each limb that goes away overnight.
Mark