The following are the basics of setting up your erhu. Watch the video attached for more details.
1) Strings - The erhu should come with 2 strings. If you are missing them, you need to purchase them. One string is thicker than the other. The strings goes round the peg and hooks on to the bottom of the erhu.
2) Qianjin - An erhu qianjin is what a nut is to guitar. It is a bunch of nylon like material thin rope that pulls the strings nearer to the neck of the erhu. If the qianjin is not there, you can for the time being use thicker nylon strings to replace it. Best is to buy a roll of qianjin string because it is waxed and of optimum thickness.
3) Bridge - The bridge is placed in the centre of the snakeskin resonator and held down by the tension exerted by the 2 strings. Take note that the grooves on the bridge are made such that the thinner string goes on the smaller groove and the thicker string goes on the bigger groove.
4) Damper - The damper is a piece of cloth that is lodged under the strings next to the bridge. The damper should be folded such that it is not too thin nor too thick. With the correct thickness you should be able to lodge the damper under the strings with a little effort, and not effortlessly.
5) Bow - The bow hair of the erhu bow is lodged in between the 2 strings. You push the bow hair inwards to play the inner string and the bow hair outwards to play the outer string. If the bow hair is not lodged between the strings, twist the end pin of the bow in an anticlockwise direction. Remove the end pin completely and you can detach the frog from the bamboo part of the bow. Pass the frog in between the strings and re-attached it to the bamboo part of the bow with the endpin. If the bow is not rosined, it will not produce any sound. Take a piece of rosin and rub the bow hair on both sides till the bow hair is lined with rosin powder.
6) Tuning - The thinner string is tuned to A and the thicker string is tuned to D. Push the pegs inwards while tuning so that they do not slip. If your erhu comes with bronze tuners you can just turn the pegs.