I just got the Skywatcher EQ3 SynScan Goto Upgrade. It comes with lots of documentation. For example on how to wire up the controller boxes. However, it does not explain, how to mount the motors, that come with the upgrade box! And neither does the EQ3-2 manual.
Hence I will describe how I installed the motors. I don't know if I did it correctly, but my SynScan seems to work, so I cannot be far off. If you use this description for assembling your own upgrade kit, you do it on your own risk! You have been warned... By the way, one screw was left over in the end. But isn't it always?
So the first thing to do is to remove your telescope, your counterweights and the flexible tuning knobs. This leaves you with your tripod and your EQ3 mount. I am describing this for my EQ3-2 with aluminium tripod (rectangular legs). If you have an EQ3, NEQ3 (round legged steel tripod) your mileage may vary. The manual first tells us to mount the holders for the motor controller and the SkyScan controller. The first one is a bugger: it's made for the round legged tripod. But do not fear! We can use a rubber band to help it stay affixed to the aluminium legs. Make sure the ground plate has contact with the aluminium legs!
Ok, so we will begin with the RA motor. This is the place where it will be mounted:
There is already a screw here, and the axle for the gear. Mount the RA gear on the axle, so that it fits nicely with the end of the axle. This will be the right height for the RA motor gear. use the two small inset screws to firmly attach the gear. Make sure not to make it to loose, nor to tight! Then you can attach the RA motor as pictured on the mount point. The mounting plate will fit snugly into the corner of the mount, and will keep the motor in place. You can jiggle it around before fastening the screw, so that the two gears fit well together. Check the photos on how this should look from the front and behind.
Ok, that's the RA assembly. Now for the Dec motor. The mounting point for this is on the other side of the EQ3. See the picture for details.