UH1 series is a direct replacement to the stock hub that comes with all three models of the Simucube 2 family of direct drive base systems,
It adds extra length to the stock hub and with smaller diameter is the perfect add-on in order to extend the motor shaft and give enough room for you center monitor in order to be as low as possible and to bring it closer to the servo axle.
At the same time it is compatible both with the stock Simucube 2 quick release and also with any 70 PCD quick release on the market,
Both the stock QR and the 70 PCD holes are threaded M5 so no need for ugly nuts.
See this great video from Greg at GTGreg on how to install the UH1-105.
If you are having problems unlocking the drive lock that holds the shaft use one of the 4 M6 bolts in one of the 2 threaded holes circled in red in the picture below, once it bottoms out half an extra turn clockwise will unlock it.
We suggest to leave a 5mm gap from the servo frame when installing the UH1 to avoid rubbing.