Hello there. I just inherited a really old stringing machine. It has a 2-point mounting system and an electric or electronic tensioner (I never did learn the exact difference on that). Now I have some experience stringing rackets but both of the machines I've used so far were 6-point cranks. As I started stringing my voltric70 I noticed that the sides of the frame (middle of the crosses) started moving apart. I did expect this but when I had only put tension on 14 strings, 7 on each side, the gap had widened by half a centimeter and that is when I lost my nerve. So my question is if it's normal for the gap to widen so much? How much do they generally widen when doing the mains? I was only stringing at 9kg or 20 lbs and maybe 0.5 cm is nothing but it's a new racket so of course I am nervous Any and all help would be greatly appreciated and I hope I did not leave out any important information.
Use Temporary Cross Strings Read this thread http://www.badmintoncentral.com/forums/showthread.php/101659-Which-should-I-go-for/page2 beginning at post #19. Significant distortion on two point machines is quite common even at low tensions. That thread will explain how to use temporary cross strings to fight the distortion.
If you're worried about 3/9 spreading you can buy (or make) a tool that goes across the racket and keeps the original width. I wish I could find it (maybe another member knows where it is) but there's a picture of a guy holding up a racket - outside a machine - that only has mains in with this black bar across the middle.