Hi Shawn,
You are so nearly there! If that was my bow drill set this is what I would do to increase the chances of getting a smoking ember...
1. Carve the 'V' notch on the hearth board a little deeper (further into the centre of your burnt socket) but hardly any wider.
2. Carve your drill a bit thinner at the burnt, blunt end. Through drilling you've created a little 'shoulder' as the drill locates into the socket on the hearth board. This means that there could be a slight gap between the end of your drill and the inside of the socket because the 'shoulder' is resting on the outside of the socket so all your effort is going into making the point of contact between shoulder and socket hot, not the end of the drill as much. By thinning down the thickness of the drill at the blunt end, you should find that the drill locates much better into the socket putting all the heat from your drilling where it should be - around the inside of the socket.
3. I can't see the top end of your drill but by keeping it sharp like a pencil and rubbing the sharp end and the socket on your bearing block with a moist green leaf to build up a waxy point of contact between the two, you will minimize friction at the top end of the drill, meaning that all your bowing efforts are going towards making the blunt end in the hearth socket as hot as possible.
4. You've created char (the black wood dust from drilling the drill into the hearth board) and obviously got smoke so you're nearly there. Use the whole length of the bow with every bowing stroke and keep the bow string taut by pressing down on it with your thumb or gripping it as well as the end of the bow. When you start bowing, use long, moderately fast strokes until you have got char forming and smoke. the char should be jet black, if not it could mean that you need to bow faster, get more rotations of the drill by using the whole of the length of the bow, or put more downward pressure on the bearing block. It's really important to have a steady hand holding the bearing block or this can become tired before the bowing hand. Brace it firmly against your shin to achieve this.
Once you have that jet black char forming and the smoke is building, gradually speed up the bowing strokes. You should have a little pile of black char forming in your 'V' notch and a ring of black char around the end of the drill where it meets the hearth - all this should be giving off smoke. The trick is to save some energy for a sprint finish as once you've filled your 'V' notch with char and the smoke it gives off has got quite a bit thicker, count thirty good, fast, strong, sprint strokes using the whole length of the bow, with good drill rotations and a taut bowstring and you should be there. The tell tale give away is a little emission of smoke from the bottom of the char pile (although you won't always see this). Total bowing time should be around 50 seconds with the right materials, but could take longer. If something isn't quite right and needs adjustment then don't be afraid to stop halfway through, adjust whatever it is and pick up where you left off. Just try to keep the char pile intact so it can be incorporated into the new pile making a bigger ember.
When you've got your ember, carefully roll away the hearth board and shelter it from wind while gently fanning it, so that it can form into a little glowing coal. This should take around 30 seconds. If you dump it straight into the tinder bundle it's likely to break up into powder again. Make sure your tinder bundle is as fine as it can be and hopefully you know what to do from that point onwards.
Hope that helps you out - let me know how you get on.
Here's an example of how long it takes when you're under a bit of pressure...
http://uk.youtube.com/watch?v=NVdA2hfr7-I
