Vixen GP Adjust slack in DEC

[Sunshine]

When i turn the DEC knob on my Vixen GP there are a few mm's of slack before gear engages, looking at the assembly it seems there are two anchor screws which hold it in place. Tightening these only makes it quite a bit stiffer, what does the smaller screw do? turning it has no effect, does anyone have experience with this issue? thanks!.

[Dr_Ju_ju]

Don't know the mount, but usually the central grub screw is what applies pressure between the gears, reducing slop\backlash. Just don't over tighten, else the axis will be difficult to move and may bind.

[Ibbo!]

IIRC

undo the central one and then gentley nip up the other 2 and test if you can move that axis, if you can nip a bit more till you have resistance then tighten the central grub screw to give you smooth movement.

 

Be careful not to overtighten go slowly a bit at a time and try to do the cap heads evenly.

[mikeDnight]

2 hours ago, Sunshine said:

When i turn the DEC knob on my Vixen GP there are a few mm's of slack before gear engages, looking at the assembly it seems there are two anchor screws which hold it in place. Tightening these only makes it quite a bit stiffer, what does the smaller screw do? turning it has no effect, does anyone have experience with this issue? thanks!.

If adjusting the screws doesn't solve the problem, you could try gently tightening the nut that holds the worm, shown at the top left of your pic.  I've come across several old mounts displaying slack, but by simply tightening the above nut it prevents the worm from any sideways movement, and the mount then drives perfectly.

Edited February 19, 2021 by mikeDnight

[Sunshine]

4 minutes ago, mikeDnight said:

If adjusting the screws doesn't solve the problem, you could try gently tightening the nut that holds the worm, shown at the top left of your pic.  I've come across several old mounts displaying slack, but by simply tightening the above nut it prevents the worm from any sideways movement, and the mount then drives perfectly.

Perfect! thanks, I have since come across a site online which hints to that same recommendation.

Thank you!

[dweller25]

Great Vixen GP advice 👍

[AndrewRrrrrr]

loosening the middle grub screw will allow you tighten up the meshing between the 2 worms using the outer 2 bolts. the middle one "works against" the 2 outer ones...