I found a picture simular like mine , you see the bearing runs to the housing :http://www.thingiverse.com/make:69579
but i watch your pictures and notice some difference the bearing holder you use is different than original
that i have from airtripper
and also the drive gear looks to me different , i got the MK8.
could this be the reason than ?
is it possible to post the bearing holder ?
i buy al the original parts from airtripper , so i has wondered why it doesn't fit.