Mistakes I made and how I straightened them out

When I started this project, not all parts came in the at the right time. So I could not strictly follow the  order of the assembly instructions that Prusa provides. One thing that was missing was the "white lithium grease". Prusa recommends only this for lubrication of the bearings.

This is the one I ordered from Amazon. Don't get confused by the brand WD40. They usually make alight oil with the same name, and this is what you should not use!

So when I got it finally, I was to lazy to take everything apart again. But today I discovered a much bigger mistake, a real stupid one.

When I got the stepper motors I did not unwrap all the cables. The ones for the z-axis where obvious by the lead screw which id also the motor shaft. But I assumed all other 3 would be exactly the same.
It turned out they are not.
I cannot tell you if the motor parameters are different, but the cable length is.
And I used the one with the shortest cable as extruder motor and the one with the longest for the Y-axis.
I had to swap them out or try to extend the stepper motor cable for the extruder.

I decided that this is the opportunity to take apart all axis and use the lithium grease to lubricate all bearings.
BTW: just applying it on the steel rods does not help so much as the gaskets wipe of most of it before it reaches the inner bearings.

Another thing that annoyed me was the crap design of the idlers in the X-axis end and the belt tensioner for the Y-axis.
I had ordered new ones from Aliexpress already:
2x Idler with two bearings 3,63€

As you can see, the ones that where used on the CNC alu parts are poorly designed. Not only the have only 1 bearing on one side, the inner diameter of the bearing is too big. So they wobbled around on the M3 screw.
The new ones on the right site have 2 bearings, one per site and the inner diameter fits properly on a M3 screw.
The other alternative would have been to use ones with teeth. Some people think they would be better as they would not flatten the teeth of the belts over time. Not sure, I usually do not put too much tension on the belts, not more than is required. So I never had that problem.

But the biggest pain was to disassembly the complete Titan Aqua hot end again. The way it is designed, you cannot easily swap out the extruder motor as everything is screwed to it.
Luckily I had enough thermal compound to assemble it properly with the new motor.

BTW: The thermal compound and also the lithium grease are both not very healthy. Make sure you wipe of the residue everywhere except where it belongs and wash you hands!