Thanh Tnut bar cho INBXX

Print 2x of each TnutBar, add some M3 nut in every slot and insert them into the aluminium profile.

The tnut bar are splitted (so you need 2x for each tnut bar) to fit them on the core one bed.

For the INBXX project you will need 16x short tnut bar and 16x long tnut bar.