The 0.770” pattern has been designed in order to increase holding strength and allow for a larger bore size (up to a 1/2”). The 0.770” hub pattern also utilizes a more common 6-32 screw, rather than the previously used 5-40 screw size found in the 0.625” pattern.
If you are unsure whether an item is compatible with the 0.625” pattern or the new 0.770” - just look for the green or blue logo on the item page. If you need to attach parts with the 0.625” pattern to parts with the 0.770” pattern we have new hub adaptors that will allow you to do so.
The 0.625” Hole Pattern has 5-40 tapped thru holes.
The 0.770” Hole Pattern has 6-32 tapped thru holes.
The 1.50” Hole Pattern has 6-32 tapped thru holes.
The Actobotics line of components utilizes two different hub patterns. The smaller of the two hub patterns measures .770” center to center across the middle of the pattern (insert picture). The .770” dimension has been chosen so that when a component is attached to the pattern with pan head or socket head screws, the ½” center bore is left unobstructed (insert picture). This pattern is repeated down the entire length of the channel with a .750” spacing from one center hole to the next (insert picture). While most screw holes in the channel measure .140” in diameter, the shared hole in-between the ½” center holes must be slightly oversized (.160”) to allow them to properly align. Both the .140” and the .160” holes work well with the common 6-32 fastener sized used throughout the Actobotics line.
While the .770” pattern is excellent for the majority of construction projects, there are times when a larger pattern is advantageous. The 1.5” hub pattern is measured diagonally across the middle of the pattern. Just as the .770” pattern is repeated along the channel around each ½” center hole, so is the 1.5” hub pattern. One common application where the 1.5” pattern is used would be the Actobotics motor mounts. Many of the mounts utilize the 1.5” hub pattern to attach the motor to channel in order to increase side stability and spread the load out on the channel.
Since the 1.5” distance is the diagonal dimension (considered the hypotenuse if you create a triangle that passes diagonally through the center to opposite corners), each side dimension of this pattern is slightly shorter. The sides measure 1.0607”. Many of our mounts utilize this 1.0607” dimension derived from the 1.5” hub pattern. Components with the 1.0607” pattern can be mounted upright inside the channel or flat across the top of the channel.
The 1.5” pattern also leaves room for a large center bore through components such as clamping hubs, bearing mounts and adaptors. Our 1” clamping hubs utilize this pattern so that the 1” OD tubing can slide through the hub without obstructing the center bore for routing cables and wires.