Groove jumping on VMS70

[tjarkpär]

Hi all,

our VMS70 does some weird jumping/skipping on random places all over the acetate. Most of the grooves are completely fine but every now and then it does overcut 1-2 grooves, as in the picture at around 5 on the scale.

IMG_20230118_172213.jpg

We have a pitch13 driving the leadscrew and using some a tad old mdc acetates. Already oiled the shaft and leadscrew, checked the motor and belt of the pitch13, as well as the depth and alignment of the needle and cutterhead.

Does anyone have an idea what could cause such an issue and how to fix it?


Appreciate every hint

[SueDenim]

It looks more like the cut depth is going shallow for 4 rotations, rather than overcutting.
I'm no expert on the VMS70, but you might want to inspect the feedscrew for debris in the thread and also check the halfnut is adjusted correctly too.

[andybee]

seems halfnut is jumping, can have several reasons, dirt, loose pin, weak spring...

[tjarkpär]

seems halfnut is jumping, can have several reasons, dirt, loose pin, weak spring...

thanks, that did the trick

[SueDenim]

Excellent!

[Aussie0zborn]

You must NOT oil the leadscrew. See the VMS70 instruction manual.

[tjarkpär]

okay after checking the bearing it went away for some time, but the dragging is now back - what is the best way to access the halfnut on the leadscrew?

[misjah]

Open the cover, remove metal clip and unscrew the nut under the lever then you can pull it out. You need to clean the halfnut every now and then and clean leadscrew

[tjarkpär]

Open the cover, remove metal clip and unscrew the nut under the lever then you can pull it out. You need to clean the halfnut every now and then and clean leadscrew

thank you - i got it out and it looks a bit drenched from what i can tell

IMG_20230123_161402.jpg

does anyone sell replacement halfnuts? pref. UK/EU?

[boogievan]

Wonder if Opcode still has some of his clones from 2009. https://deepgroovesmastering.com/.

[Aussie0zborn]

Don't forget to clean the rotating leadscrew with a wooden toothpick to remove any debris.

[tjarkpär]

Thanks everybody, halfnut is changed, feedscrew is properly cleaned and everything is up and running again - better than ever before.

[Mavis]

Thanks everybody, halfnut is changed, feedscrew is properly cleaned and everything is up and running again - better than ever before.

We have a similar probelm, where did you find the new halfnut?

[leemichael]

Open the cover, remove metal clip and unscrew the nut under the lever then you can pull it out. You need to clean the halfnut every now and then and clean leadscrew

thank you - i got it out and it looks a bit drenched from what i can tell


IMG_20230123_161402.jpg



does anyone sell replacement halfnuts? pref. UK/EU?

Surprised that worked at all! There’s nothing left!