The organ is almost finished, but I have some problems with the short pipes.
The short pipes don’t sound so good as the long pipes. They have more overtones and less of the foundational tone. It is also harder to get any tone at all from them, when operating the bellows. They are easily overblown.
I think it is because all pipes have the same diameter, because they are made of plastic tubes with fixed diameter. The scaling is not constant. In my next organ project I will make the pipes myself, and maybe use paper mache (papier mâché) to the pipes and organ kernel of clay.