Hi Rob,
This is one of the classic problems that all bowmakers encounter and that regularly frustrates new bowyers (it sure did myself). Now, you can't tiller ANY bow to reach any draw length because all wood has its limitations (eg. you're 56" balsa wood bow won't be 50# @ 30"
ad infinitum). There is magic in bow making, but the magician needs to have something to work with
. Here are a couple pieces of advise to help make draw weight. This has been said better by others, but here is my rendition:
1. Get a scale and set up a tillering tree;
2. Rough out your bow so that it just bends a little a floor tiller;
3. Visualize (or draw out),
before you start tillering, the limb profile you want to end with;
4. SLOWLY start removing wood on both limbs (to the point where you get frustrated that things aren't moving faster);
5. Start checking draw weight early, and check it often);
6. Get the bow to a short string ASAP;
7. Always keep in mind your desired limb profile (point #3), but work with what the wood gives you (e.g knots etc);
8. Never bend a bow past its intended draw weight; and,
9. This one is the key to tillering: Fix any problems in tillering before you draw the bow any further (e.g. the bend should look perfect before you go on);
Following these steps you should end up at the desired draw length and draw weight every time.
good luck,
Gabe
