Can the tiller change?

[Prarie Bowyer]

So on the tillering tree the curve looked good.  It checked out fine with my little square block tillering tool.  I did the final sand shot it for about 30- 40 min.  Put a finish on it and shot it some more.  It shoots well.  It feels nice and I like my groupings with it.  I took a picture of it at full draw and the bottom limb is flexing noticably more than the top limb a few days later. 

It's just a bit perceptable at full brace.  I didn't see that before and I wonder if it was there and I missed it or it's a product of shooting it in?

It's a Hickory, Bamboo, maple trilam bow.  Pics are under "another bow finished".

Thanks

[Del the cat]

Yup, This happened to me a while back and I posted exactly the same question.
It was an Ash flatbow. It was fine, I'd shot it for a few weeks and I just put it up on the tiller to check the weight before signing it with weight and length.
I felt physically sick, the lower limb had lost about 10# and was bent double (slight exageration).
It looked like a real beginers bow.
If someone had showed me the bow I'd have said it had been overdrawn or trodden on!
I lost about 15-20# re-tillering it, then I heat treated it and got most of it back.
It started at 40# and ended at about 36#.
Not my favourite bow but it taught me a bit... especially that pride comes before a fall.
Del

[Prarie Bowyer]

Ok so I'm not loosing my mind.  The bow unstrung looks fine.  How did you heat treat it?  This is a tri-lam bow so I'm afraid to cause it to delaminate.

[Del the cat]

Ok so I'm not loosing my mind.  The bow unstrung looks fine.  How did you heat treat it?  This is a tri-lam bow so I'm afraid to cause it to delaminate.

I did it slowly with a hot air gun at about 350C. I wouldn't try it on a laminated bow.
Del

[PEARL DRUMS]

If your bow was tillered on your tree at ceneter, then you grab the bow say 1" lower than center when you actually draw and shoot the bow it strains the lower limb more becasue it shortens it up, hence more set and a "looser" bottom limb. Try posistioning the grip of the bow in the same pressure spot on your tree during tillering that your hand would represent during shooting. Snip some off the top limb and see what happens.