Hopefully someone has an answer to this question.
I've got a takedown longbow with 2 sets of limbs for the same riser. One set makes a 61" bow the other a 59" bow. I've been shooting the 61" for 10 yrs so my brain is pretty trained to this setup. The knock point is 3/8" with a 1/4" tiller.
In order to get good arrow flight with the short limbs I have to set the knock at 3/4". The tiller on this setup is 1/8".
The problem I have shooting the shorter limbs is the bow hits high with the same hold on target, so when switching limbs I'm going to have to retrain the ole brain. I really don't want to go through this everytime I swap limbs for one reason or the other.
My question is, if I retiller the short limbs to 1/4", will I be able to lower the nock point and therefore hopefully be able to hold like I do with the 61" limb? Or is the hitting high problem being caused by the shorter limb or a combination of tiller and limb length?
I have a similar situation with a Bear Custom TD and matching Grayling limbs, both 60" and 66# with different tiller.
It may be possible to tiller the bow, by removing material on the upper limb to increase the tiller to 1/4", but that is a lot of work and you will probably need to refinish the limb.
However, you may be able to add a shim under the upper limb to change the angle and the tiller. I would start by trying some heavy vinyl tape, like the black vinyl electrical tape that is thicker than the standard tape. Your find it at NAPA Auto parts. Put the tape on the limb then mount the limb and check the tiller. You can experiment a little. If the thickness becomes too much, you will end up with a gap, and flexing when you tighten the bolt. I would advise againts this if you see any flexing when you tighten the bolt for the limb. The stress could cause a problem. I you are unable to fill the gap with strips of tape, I would call the bowyer for his advice.
If the tape works, then you might assume retillering would also work. To get around the possibility of flexing due to the gap, you might find a fiberglass wedge ground to the desired thickness that you could epoxy to the limb.
You did not mention, if you checked the brace height. I would not assume that both limbs are going to perform the same with the same brace height, nocking point etc. Try tuning the second pair of limbs, starting with a low brace height, shoot 3-5 arrows, then twist the string about 5 turns to raise it 1/4". See if you can find the sweet spot for the other limbs, before you retiller. If that does not work either, then you can retiller the upper limb, but it may never shoot to the same point.
The shim is a good idea Hud, I'll give it a shot.
from what i know you could trap the limb to get your increased tiller too, its much less tedious than tillering a whole limb.