I'm going to have another go at Bowdrill next time. Been Watching Wilderness Outfitters demo on it. What I will do next time:
Get softer wood for the heath board and drill.
Strip the drill of bark to make it more uniform shape for cord to grip.
Possibly make a longer, stronger bow.
Use green wood for the bearing block.
I think I should be well on my way to getting a flame with these mods. I think the last setup was too hardwood. Drill bit was bouncing about. Bow was too short to get a good push and the bearing block was shouldering out as it was burning up.
Well, that's the plan anyway!