Modulgrav inside ring engraving issue

We acquired a used Modulgav engraving machine a while back, and have
just been starting to get familiar enough with it to use it
reliably. While we have some other ideas for the thing, the main
opportunity at this point seems to be offering inside-ring engraving
to the people who are commissioning rings.

This is turning out to be a problem, though, because the inside-ring
module is balky. After we’d gotten it, in our first serious trial of
the thing, it stuttered enough on the horizontal movements that it
ended up being unusable. At this point we sent it to Gesswein to have
it reconditioned, which they did, and it seemed to be working at
first… but now it’s stuttering again, and again on the horizontal

Now, working the control back and forth like a pendulum for a while
moderated the stuttering enough that we could use it, but I’m pretty
concerned about what’s going wrong here, and how we might be able to
deal with it. My best guess at the moment is that the lubrication,
whatever it is, is congealing on the bearings. If that’s the case,
working it regularly ought to be able to keep it usable- but I don’t
KNOW that’s the problem or the best solution!

So- anyone have a Modulgrav with an inside-ring attachment and can
offer me some pointers to get it and keep it working smoothly?

Any pointers for any of the other attachments will also be very
welcome, and sincerely appreciated.

I guess if we end up having to replace the thing with a dedicated
inside-ring engraver, we could consider it… but there’s enough
other stuff we want to do for which the Modulgrav looks like a good
choice that I’m reluctant, especially since we don’t really have
enough space for yet another engraving machine…!

Thanks much for any advice and tips!

Amanda Fisher