There appears to be some confusions regarding Dual motors. Maybe I am the one who is confused... Let's answer each question one at a time.
Nandric: "As I or 'we' (Lew included) thought there are at least two
Dual motors: 701 and 721....... Lew suggested to use the Dual motor for his Lenco. I have no idea what to do with my specimen."
Yes, there are two Dual direct-drive motors. EDS-1000 from 701 and EDS-1000-2 from 721. 701 uses a heavier platter and 721 uses a lighter platter.
From what I read and if I understand Lew correctly, he wants to use the EDS-5000 motor from the CS-5000 belt-drive turntable and apply that to his Lenco, which is doable, and it has nothing to do with the 701/721 motors. I don't see how you can use the EDS-1000 and EDS-1000-2 motors for the Lenco since the Lenco is an idler drive design and the 701 & 721 are direct drive. I don't know what "specimen" you have or what exactly you are trying to do. Please elaborate.
"Your contribution was primarily directed to the Goldmund Studio problem."
The earlier question(s) was directed at the Goldmund issue so I answered accordingly. I must add that I would only repair the Goldmund using the Dual motor if the Goldmund platter would fit over the Dual motor with no or very minor machining. Otherwise, your Goldmund is not a Goldmund anymore and you're better off just transplanting the Dual motor onto a custom plinth and make it a stand alone arm-less direct drive turntable.
"We thought that if this motor is something very special some other applications would be interesting."
The EDS-1000 and EDS-1000-2 motors are, indeed, very special and is great for making your own direct drive turntable.
Here is a gallery of pictures of a 701 and its innards.
Have fun!
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