designing a better kit frame.

[Hawiian Cadder]

After the team discussion Tuesday about how our build season went, one thing came out above all, making the season go faster. getting the robot done 30 min before 12:00 on bag day is not something that i would like to repeat.

after the season ended i toyed around with the idea of creating a custom kit, that could be assembled into a frame that would accommodate any drive, and any game, with only minor modification. after a couple weeks, i cannot think of any other way to improve the design.


the basic idea is to use the pocketing in the frame for more than simply removing weight. because pockets are usually included in a frame anyway, why not use them for more than just weight savings. the result is an exceedingly flexible frame, that weighs only 15 pounds, no matter what drive-train it contains. (includes frame, axles, bearing blocks)



This image shows the basic pocketing pattern for the side of the frame rails. the holes are 2 inches in diameter, and the other holes are clearance for 10-24 bolts, or 3/16 rivets.




these images show the bearing blocks that fit inside the pockets. they allow for the bearings force to be dissipated over a larger area of the tube, making it less likely to bend. the bearing hole is a-centric by 1/16 of an inch in bot the x and y directions, this allows for chain tensioning as well as the raising of the outer wheels in a tank drive by 1/8 of an inch. with this setup and a few half links, #25 chain can be kept tight without any sliding hardware.




(second image coming, photo-bucket upload is taking forever for the last 2 percent)


This image shows how the whole frame combines using gussets and rivets. the holes on the top of each frame rail are 3/8 in diameter, and have the same spacing as the kit frame, thus allowing the standard kit frame to be integrated into this frame. they also allow for bumper mounting ( the bumper has a pair of brackets that come out of it, these go on top and on bottom of the frame, and a 3/8 d clip goes around and through the center.




this frame should, with minor modification, support the following drive setups;

long orientation tank with up to 14 wheels.
short orientation tank with up to 8 wheels
long orientation mechanum with any mechanum size up to 10 inches
short orientation mechanum with any mechanum size up to 6 inches.
slider drive in any configuration

by rotating the elements of the frame 90 degrees (so that the 2 inch diameter hole is vertical) the frame can support

tank drive of any variety
holonomic drives (normal omni wheels at 45 degrees)
with the manufacture of a new top piece, a revolution swerve module can fit inside the 2 inch hole, and co axial swerve is possible.

any thoughts on how to improve this? also, would it be legal to fabricate the pieces before season, without assembling them, provided the CAD, all previous versions, and the design notes are open sourced.


thanks to teams 111, 1114, and 40, seeing their robots at CMP served as the major inspiration for this project.