That dont look bad. Not at all for a first. Congratulations, and welcome to the sickness. ( or the cure? ( to borrow from somebody elses signature ) ) Now, If you dont mind, I am gonna disect your tiller to give you something to look at for improvements on your next bow. We all want to improve, but we wont without constructive criticism.
So first point, wear safety glasses when shooting this bow please. That lower limb is scary. It cracked there because if you look, it is bending way to much in the outer limb. Almost all the bend is happening there, when the bend should be even across the entire limb. Now that is obviously difficult when your stave already bends in weird places, for example the upper limb. Ironically though, I think you did your best tillering on the upper limb and can only say it bends only a touch too much at the tips, where the lower limb bends way to much. You did a much better job on the much tougher side of the bow. Actually, its darn near perfect except for the last 4 inches or so where it bends too much.
On your next stave, make sure both limbs bend the same amount. Do this by measuring the distance each tip bends. Pictures help too, you can stare at them long and hard without actually stressing the bow out for long periods of time.
On your form, drop your elbow. You want your elbow, arm, and arrow to form a perfect line with each other. That way, your arrow is literally an extension of your body. Pointing your arrow will be just as natural as pointing your finger, because it is exactly in line with it. Mirrors help with that. Here is a pic of what I say is perfect form...
Notice how the elbow to arrow tip are all in perfect line with each other. That guy in that pic is gonna hit what he was aiming at. Anyways, I hope you didnt take any of what I said as being rude or know it all. I am just hoping to see you improve. And I know you will. Good job, good luck, and look forward to your next bow. I have itching to do a sweetgum for years, its on my unfinished business list. Itching to see somebody build one. Soon as I see one standing alone, minding its own business, and nobody around.... somebody is going to see only a stump where a tree once stood... And it better happen soon, with all this itchin, I may get a rash.
I would like to add one last thing. Get your bending even at brace or before if you can. But certainly at brace. You will brake far fewer bows if you make sure the stresses of bending are even throughout the bow when you get it strung up, before pulling on that string. By time you are pulling it back, you should only need minor adjustments. That way, high stress areas, like where your bow broke, are fixed before they become high stressed and you wont break them.
