With the new game, I am interested in the ability to strafe.
Being able to strafe is useful with:
- Quick repositioning
- Avoiding other robots
- Finding the best real estate in the endgame to start to expand
- Strafing while simultaneously facing the goal to shoot, such as traveling in a horizontal arc (faster scoring)
- Increased agility in gameplay
- More creative routes in skills match
However, with many teams declaring their use of 6 motor drives for the Spin Up season, I fear that the traditional x drive (using 4 motors) would not be able to survive amongst the more powerful drivetrains. However, I am confident that strafing is an advantage in this game due to the reasons above.
Thinking 4 motor drives to be lackluster, I set my sights on a drive with both strafing and more power. In my research, I came across the asterisk drive. Using the traditional layout of a 4 motor x drive, it adds the ability to be more offensive with two wheels oriented on the flanks of the drive, arranged in tank style. This 6 motor drive, is stronger than a 4 motor drive but it does not compromise the ability to strafe.
To make this work, I decided to use a combination of drive ratios.
The wheels in the x would be set up as follows:
2.75" omni wheel, 300 rpm (600 cartridge geared 1:2)
The two tank wheels would be set up as follows:
3.25" omni wheel, 360 rpm (600 cartridge geared 3:5)
Attached below is an image of the drivetrain I envisioned.
The linear speed of the x wheels would be 40.73 in/ sec, and the linear speed of the tank wheels would be 41.89 in/sec.
The drive program will be adjusted to account for the slight difference of 1.16 in/sec. in linear speed between the two wheel sizes.
To easily picture this drivetrain, imagine the speed of a 3.25" 360 rpm 6 motor tank drive, with the ability to strafe.
To facilitate this discussion, I will list my compiled pros and cons of this drivetrain.
- Increased forward pushing power for match play (compared to standard x drive)
- Combining the agility of x drive with strength of tank drive
- Extra 2 motors might be better used elsewhere
- 2 tank drive motors not always driving (e.g. when strafing sideways), so wasted motors in drive
- Still less torque than a tank drive with similar speed
I wanted to ask the community: is this the right design choice? Is there a better solution, and is strafing less important than I think? Is this drive overly ambitious, and the tradeoffs are not worth the benefits?
Resources to familiarize oneself with asterisk drive: