Seiko Lord Matic - Tighten Rotor

[Waggy]

Greetings all,

I am restoring a Seiko Lord Matic (5206A) and have a question about the automatic works rotor. When I opened up the watch the rotor was very loose and (fortunately) this was due to it not being screwed on very tight and not a bearing problem and I removed it with a few turns using my fingers. However, the thought struck me that I'm unsure how to put it back on, what tool should I use as it is a chunky rectangle and not a slot type where I could use a screwdriver (see picture below - Note: this is a similar movement picture from google as the picture I took of my watch isn't as clear). I don't want to grip and try to tighten it with tweezers as I think the chances of slipping would be high and I probably couldn't apply enough torque this way before damaging my tweezers and/or slipping and scratching up the watch.

Anyone have any ideas what tool I can use for this job? Maybe I could 3D print something if there is no easy answer out there?

[KarlvonKoln]

I have encountered those kind of mounts before.  At the time, I used my older (non-digital) vernier caliper, as an ersatz wrench.  It worked.  I'm thinking of making a purpose-made wrench from heavy brass though.  But I haven't worked on another automatic like that in a while now, so I haven't made it a priority.

 

[HectorLooi]

I usually use a pair of eyebrow tweezers.

[Waggy]

Here is what I came up with, on the printer now...

[RichardHarris123]

Would it be better with a  knurled handle? 

[Waggy]

Hmmm maybe in rev 2