The thru-holes on this adaptor align with the 16mm pattern found on almost every goBILDA part but are slotted outward for edge-case situations where you need to align with holes spaced 24mm across the center. The counterbores allow heads of M4 socket head screws to rest below the top surface so you have a clean slate to fasten a part to. The counterbores are machined as a hex-profile in order to accept and capture an M4 locknut if you prefer to have screws come up through the bottom.
The remaining holes are positioned on the Actobotics 0.77” pattern, and threaded to 6-32 UNC so that you can fasten any Actobotics thru-hole component with ease.
As an added bonus, a bearing counterbore has been added to the bottom of this adaptor so you can use it to hold and capture a 1611 Series flanged bearing.