Help! Belt coming off at 45rpm

[block]

Bought a systemdek iix900 for a spare system. Wanted to buy a cheap tt to play with and it seems to have good reviews but maybe I should have started with rega.

Plays 33rpm at the upper rotating pulley, I think you call it, ok.

But when I change the belt to the lower 45rpm the belt starts to move up as the platter rotates and the belt either ends up coming off or goes into the 33rpm.

I googled the problem and there seems to be a fix/adjustment but I don't really understand. Its something about a grub screw located between to screws which I found but don't know how to adjust it to raise the pulley.
Do get access to it by removing the base?



"Postby wobbleu » 30 Jul 2008 23:07
Larz
If you look at the top of the plinth in the rear left corner - you'll see 2 screw heads (these hold the motor frame in place) - between the two screws and bit more to the back there's a hole in the top-plate. Inside that is a grub screw which can be adjusted to set the angle of the motor assembly - if you adjust that you'll get the belt running true without affecting the 5mm gap.

You might find it easier to loosen the motor frame screws 1/2 a turn before you adjust it - and then tighten them up when it's set right.

It can be done with the platter in place too....

Adjust the suspension on a TT from the bottom ? whose stupid idea was that then? some TT designers get it right :D

regards C"

[Fran]

Can you see the 3 screws he's talking about - the two that hold the motor and the hole for access to the grub screw beneath. Juding by his description you don't need to go at it from the bottom.

[block]

Hi Fran
Yes I can see 2 screws holding the motor I think holding the motor to the top wooden base. The middle is a hole which I presume is a grub screw which I don't have a clue what you use to adjust.
Now looking closely I think an Allen screw is missing as well holding the chassis? There's a simple instructions manual calling it the " chassis adjustment point"
There's 3 of them and one of the Allen screw is missing. I think the hole on the top base is not aligned with the hole at the bottom where the missing screw is.

Can I unscrew one of the other screws and get a replacement screw and this is the problem? Because aligning the holes seem to tug on the belt a bit making it tighter.
Though from the eye it does look quite low.
The guy selling it said he did all the adjustments and is ready to play. I think he only fiddled about the arm.

[Fran]

I'd say its a fairly standard grub screw so if its missing you should be able to pick one up fairly easy on ebay or whatever. You might even be able to get a sampler pack of them so you'd have a variety. As I understand it the motor is held with the 2 mounts, and the grub screw provides adjustment to get the tilt right so that the belt runs in the middle of the pulley.