I'm having problems with my tillering.  I have made a few selfbows out of red oak, my problem is they always come out very light, 20-30#.  I even tried one out of Osage, but it too came out very light.  Any advice would be appreciated.  By the way my Osage bows all cracked at pinhole knots.

I've been using a 3" piece of wood to check my tiller, very hard to eyeball.  I'm going to make a gizmo tomorrow and give that a try.

The gizmo is awesome. It makes tillering a breeze. I'm betting using one will fix all your issues. Also remember, don't use the long string any longer than you have to. Get the bow to brace as quickly as you can. The long string will lie to you.

If you are consistently ending up light then it is not just a tillering problem.  Tell us more.  Are you getting hinges and then having to take off too much wood to correct and then seesawing between the limbs?  What design and instructions are you using?  

It might help to start from the beginning.  Get a good book and follow it closely. I highly recommend both Dean Torges "Hunting the Osage Bow" and the "Traditional Bowyers Bible Vol 1"

OK I just ordered Hunting the Osage Bow.  Thanks for the advice.
My plans came from some old magazine, a selfbow or American flatbow.  My bow is 64" long, and your right I do chase hinges.  I'm also using my long tillering string too much.  I'll adjust with my next bow.  
I found a farmer in South East Kansas (Tornado zone) who sells fence post.  These are Osage Orange or Hedge apple as they call it.  And he assures me he can get me some straight knotless logs. He drives up to Nebraska frequently, so maybe soon I'l have some Osage.

By the way I love this site and it's members.  Reading the post from Turkey and hearing everyones encouraging responses instead of scolding the guy for posting, really moved me.  Thanks for being the good Americans and not the "Ugly" ones.

If getting the fence post ask him to seal the ends when he cuts it.
Most of the posts I've seen we're not sealed nd checked badly .

Cutting your own bow wood is usually a better option.  I have been some places whereevery tree would make a bow but most are 1 in 100 trees.  I once went to a place that had thousands of trees and I found maybe 4 that were marginal bow wood.

Get the book.  Follow the book and you will learn how to make an osage bow.

While you are reading why not try a simple board bow?:   http://sticknstring.webs.com/ferretsboardbow.htm

Here's how I tiller:  http://hedgerowselfbows.webs.com/fromblanktobow.htm

Make yourself one of these, no more hinges to chase if you use it correctly.

http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=001047#000000

Thanks everyone for the info/advice.

I recommend Paul Comstock's book "The Bent Stick" for beginners myself. That's where I started. Personally, I think Dean's book is a little advanced.

Learn the art of taper tillering instead of tree tillering to begin with. Difference being, when you apply a taper, limb bends accordingly. Tree tillering, you remove wood where you think it needs it to get the limb bending properly. First method, you won't get hinges. Second method, beginners are sure to screw things up. I know I did. So add Paul's book to your list...........Art

After it's floor tillered and I get the short string on it, I check the draw weight with one of those spring loaded scales and keep checking it after removing wood.  I never stress the limbs to the weight I'm trying to hit until the very end, draw it to about 5 pounds under.  Eric's gizmo has been the biggest help to my tillering by far.