Some of the plastic cameras have the same problem. What I do is fold a piece of cardboard, such as the box my 120 film came in. I have to tare off a bit on the side, and then put it under my roll of film. It works like a spring, holding the spools in place. Not having done this with 6x9 Lochkamera I don't know if this will work, but it's worth a try.
james >> >> Right now I have a 6x9 Lochkamera >> (http://www.pinholeresource.com/products.html#lochkamera) and the film >> winding drives me nuts. >> If I don't secure the winding-knobs with rubber bands, they wind up as soon >> as I let go of them. And even if I use rubber bands, the film does not get >> winded (sp?) tightly. In fact, it's usually so lose that I get light damage >> at the edges of the film when I take the film out of the camera. >> >> How would you say that the Zero 2000 performs in this respect? >> >> Regards >> Soren