When mounting your Second Shooter Camera control rig onto your Slider the stock parts do not cut it (sorry Kessler Love ya) This gives you a more solid base and allows you the ability to place your Second Shooter on your slider and have it always facing one direction (with the cables out on one side) Outside of all the other mods I have made to my rig this one will help facilitate deployment in the field and give you a NICE Solid base. Originally modeled with 4 spokes the slicing software made a mistake and I liked it :)

To mount this use this adapter (or something similar)
https://www.amazon.com/gp/product/B014EIGFIE/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
And this to make it fit on the Second Shooter and the slider (I couldn't find a 3/8 to 3/8 adapter so I had to use 2 parts)

Push the Camvate through the ring with its threads out the other side slowly spin the ring to tighten the screw. It will start to get tight keep going it will pull the screw flat against the second shooter or slider and your all set.

Put the ring on your second shooter or the slider then spin mount the other to the other :)

I repaired the original model it had a glitch in it (not reprinting it) But the pictures you see are of the print that mine made (that did not translate here hence the reason I remodeled it)
I did post a variant :) of the one that printed.

Just FYI do an 80% fill and it should be 15 cm across (forcing myself to use this metric system yea hehe)

Good luck and happy shooting.