Dr Boo's Combined Kossel 1515 Slider and Self Locking Carriage remix V1

I put together a mashup/remix of two items I'm using at the moment - a 1515 slider and a self locking carriage for the Mini Kossel. There are a couple of reasons; firstly of course you don't need the screws to join them together. The second reason is that this allows the carriage to be printed in a vertical orientation which greatly improves the strength of the little islands around which the belt wraps and locks. That's because the layer orientation is across/against the pull direction of the b