When I learned of the new motor rules for this year I was crushed, I realized that the best drivetrain was no longer possible: H drive. This saddened me for many months until I took matters into my own hands. Rather than simply use 1 motor per side and 2 for sideways driving, creating a pitiful excuse for H drive I had an idea, what if we could just use the 4 regular drive motors to drive sideways as well, giving greater power and speed. Thus, the bootleg swerve project was born, an idea to make 4 motors H drive a reality and for less than mk4 swerve. After a long week of CAD work, I am ready to reveal my first design. The idea is it uses a standard WCD drivetrain, with 4 Omni wheels. The difference is that the gearbox has an extra sprocket that goes into a REV 90 degree gearbox, which then goes into an Andymark Evo shifter. The shifter then has one gear ratio removed, resulting in a clutch mechanism that allows the motors to drive the robot to drive normally and just spin the shaft, until we shift into gear, activating the H drive module. Naturally this means that it can only go one direction, which is why we have another Evo shifter connected to the other gearbox, allowing for H drive motion in both directions. The only issue is that with this setup the robot can only go sideways while going forward. This is why the next design will incorporate another 2 Evo shifters for the regular drivetrain, allowing for H drive while moving in addition to H drive while stationary. Please share your thoughts on this new best drivetrain ready to take over swerve. /s
I did NOT see that /s my first read LOL
I had an idea very similar to this when I first heard of the new rule. You beat me to actually opening up CAD to do so.
I see that /s, but I believe you might be on to something actually viable here… If it’s easier than swerve to put together.
Edit: I tend to think most drive train ideas can be engineered into a working and viable product. Even meme designs 
Needs some differentials.
not a cots triffy swerve 
This reminds me of the quad-directional tank drive I designed one time…
Totally impractical, but fun nonetheless.
Possibly,at least from an electronic perspective there are less motors and can devices to worry about, might be something thrifty bot could look into
I have to know how this works
I was thinking it over a little more, and I’m wondering if this should maybe be a type of shifting gear box with 4 motors that all have the individual ability to supply rotational power 1 of 3 output shafts (1 out each side and 1 going out the middle front). This paired with a sort of butterfly drop mechanism for a middle traction wheel(s) to keep the robot from cosplaying a hockey puck.
Basically, it operates like a normal tank drive, but with the side-strafing wheels tied-into the power output of the drive train. So the front modules would be powered from the right drive via a live axle and bevel gear on the front right wheel, and the back modules powered by the left back wheel (note the long belt across the front connecting the two sides, if you didn’t do this the wheels could fight each other).
The air cylinders can be actuated to deploy the strafing wheels out, lifting the main drive wheels and allowing to the robot to drive with the “front” effectively being rotated 90 degrees. All wheels in the system spin at all times, so there’s no need for a shifting PTO or anything (similar to a butterfly drive).
The concept was for situations where you wanted a tank drive, but you had a scoring element that required fine-tuned lateral positioning (like this years game), and didn’t want to deal with the problem that tank drives typically have where you have to back up, turn, reposition, turn back, and try again.
Find god.
That’s really cool, do you have the CAD file you could share?
Right here
Sure.
Full disclosure, the design is basically just a rough concept and it’s missing a lot of details. It’s based off of an old tank drive design that was modified to accommodate this idea. Incidentally, I included both the Inventor PackNGo version and a .STEP in the zip in case the .STEP broke all the constraints.
You’re looking at it
The one true god drive drain would use a differential + butterfly so that the perpendicular sets of wheels could be switched between and then skid steering would just engage the perpendicular wheels
This was a real Poe’s law moment for me. Summer CD has caused irreparable damage to my mind and soul.
You say this as if you aren’t looking at a biblically accurate FRC drivetrain.
Reminds me a bit of 1625’s lobster drive.
