My Monoprice Mini Delta is a capable little machine - but it seems to work way better when the microSD card is connected via an extension cable. This is the one I bought: http://shor.tw/1bb
I designed and printed this little cover to go over the adapter, without blocking the microSD card slot or the ribbon cable in the back, and I could hotglue in two small 3mm tall, 6mm wide cylindrical magnets.
I also added a little mark to the top of the model that shows the orientation of the microSD so you won't insert it backwards/upside down.
It works like a charm. :)