I need some weights for my steadicam

[laserblazer]

I've finished the construction of my steadicam and now's the difficult bit, balancing it. I've fixed a plate at the lower end to attach balance weights and it's a question of getting the weight just right. Ideally, what I need is a some disks around 6cm diameter weighing around 25g each. They don't have to be round. The idea is that the thing is made pretty well from scrap parts, so I don't want to spend more than a few pounds if I can help it.

 

Any ideas?

[FN-GM]

Science use weights just like that, go down and steal some

[laserblazer]

I did think of that but they would be missed. Oh and ideally there needs to be a hole in the middle to attach them to the plate.