The combination of woods being used is very important.
If the "drill" is too hard and the "hearth" board too soft for example, you will just drill through the hearth board very quickly.
Poplar sounds the most likely from what you mentioned above, make a drill and a hearth from that if you can. Lots of other possibilities such as hazel, clematis, ivy etc but the hard exotics are unlikely to be much use as they're too hard !
Round the end of the drill, you want a shallow curve on it for increased friction area, rather than a point which will just drill through.
the "v" notch in the depression in the board is quite important to get right, it should stop just short of the centre of the depression (so as not to create a nipple on the end of the drill) and undercut a bit to allow space for the ember to collect and grow in size.
The ember is basically just smoking, black powder formed by the friction of the rubbing pieces, it is unlikely to burst into flames by itself, but when blown on gently should glow red.
The hearth board should be stood on something else so that when a sizeable ember has collected under/in the v notch, the hearth board can be carefully removed and the ember transferred to your pre-prepared tinder bundle, maybe with a bit of char cloth in there as well, or some scraped up birch bark, and then blow long and firm on the ember and tinder bundle until it starts smoking lots and then eventually bursts into flame. Job done !
It's a combination of downwards pressure and moderate speed on the drill bit that creates the friction and the dust that forms the ember, aa drill about the thickness of your thumb is about the right size, too thin and the friction area is too small, too thick and it will be difficult to rotate when doing it by hand. The first couple of minutes of rotating the drill is just to bed the end into the hearth board to conform the shape of both and give matching surfaces that will provide the friction, then you can increase the downwards pressure and should be able to see the powder of the ember forming along with the smoke.
My guess is that your woods were too hard to release a powder and so you were just getting heat and smoke but nothing that could physically be transferred to a tinder bundle.
Tinder bundles can be lots of different things, but typically might be a good sized ball of very dry hay or dried grass or similar, perhaps with char cloth or scraped up birch bark in the centre, and once alight the tinder bundle is then used as the base of the fire to add dry twigs and sticks too to build the fire proper.
It's very satisfying to do, doing it manually with a bow adds in a few other variables too, so a good idea to try it out this way first as proof of concept on the materials used etc before then worrying about the rest.
I've done it a few times with a bow just for fun and to prove to myself I could do it, but usually go for an easier and quicker method when actually wanting to get a fire going rather than playing !
