If want to use a http://www.thingiverse.com/thing:4042 together with a http://www.makergear.com/products/plastruder-replacement-parts style grooved insulator on your mendel then this bits help you achieve that.

Print and clean all the parts and align then:

1) slide insulator into cartmount
2) slide plug over the top of the insulator
3) put brutstruder on top, but don't attach any bolts yet!

Now some nuts & bolt work:

4) run M3x20-ish bolt thru the cartmount, plug and brutstuder mount hole below the springs and fasten it using a captive nut
5) attach plug to brustruder using an M3x16-ish bolt and fasten it using a captive nut
6) find a way to attach the tip of the plug to the cartmount since there is a small clearance issue

And finally attach it to your mendel X carriage