Black Frog, you got me thinking. I could probably mount rollers on a piece of wood that hangs from underneath. Wood is real easy to adjust to an exact weight. I don't have much in the way of metal working tools , but I do have planers, sanders and an electronic scale to get the weight real close on a piece of wood.

This is what my arrows rest on now. I bet they'd work for hanging the weight and they only cost about 59 cents. I don't like the bolt for a weight because it has to be placed exactly the same way each time or the reading will vary a bit.