Once you’re looking at the instructions there one point to keep in mind:
However, if i remember correctly, Dennis mentioned that he broke one bridge because it wasn’t strong enough. So if you’re not in the mood to experiment, go exactly as per his instructions and use the big bridge.
Before putting together plans to make the proper one, Dennis showed me a simple Esraj with a cookie-tin soundbox (without sympathetics) as a draft. I hope he puts instructions up for that as well. It’s a simple instrument and is nothing to boast to your friends about, but it will play just fine and get a lot of beginners started.
You can also make a basic Taanpura if you’re interested. Of course it wont compare to a traditional Taanpura, but judging from the audio sample Dennis has on his website, it sounds good enough to use on stage for casual gatherings.