I recently built a Vzbot gantry on an Ender6. For the hotend I had a V6 style hotend and an Eddy BTT. I initially created a holder just for the BTT but then I realised that it would rattle when using the printer as normally the V6 Fan is not attached to anything just clipped to the heatsink. 

I used the Golliath fan mount to modified so I can be mounted and unmounted from the PrintedHead without having to disassemble the whole toolhead. So the fan is screwed at the bottom of the toolhead. 

As part of this change I also added a way to add the Eddy BTT as close as possible to the nozzle. 

For connecting the Fan and the BTT holder you need an normal M2 Screw of maximum 12mm, if it is self tapping you can probably go longer and go through the plastic for a bit maybe to 14mm.

The nuts I'm using to secure the Eddy BTT are M3 square nuts so that they don't spin. The screw length should be greater than 20mm but less than 25mm. I only had 26mm so I added a nut at the beginning so that it would fit. 

BTT Eddy offsets I'm using are below 

x_offset: 25.5

y_offset: -12.5

Don't be like me and forget to adjust the bed_min and bed_max if you changed the offsets those need to be recalculated.