I appreciate the references to CheapoSwerve, I never intended that to be the official name, but I guess itās stuck :P.
Iāve been iterating the design for the past 4 months or so for a separate project, and have since made it way more viable for FRC-related testing. Itās been assembled, iterated, tested, and it works really well.
Hereās a link to the updated design, and here are a few teaser shots:
If you want to build a swerve for the sake of having one, I highly suggest looking into FTC Team 11115 Swerve. It will be cheaper and easier to drive safely wherever you want.
If memory serves me right, most of the parts can be 3d printed and will be much more cost effective. Also, if you are looking into control systems as well, take a look at this thread and this thread I posted to group building a mecanum bot for a school project. It is significantly cheaper to not got through FRC/FTC legal hardware and do Arduino instead.
Eh, Youāve got about 6 weeks pre season. The last time I did a clean room swerve implementation it was sit down and code for about 4 straight hours to get robot centric working and then field centric was about another 10 minutes to implement (and then about a week to debug because I didnāt have hardware and the gyro used one direction for positive and the robot for the other which led to weird results)
(For the record, my field centric code is in its entirety below, itās really quite simple matrix math)
public static Vector2d TransformFieldCentric(double x, double y, double headingDegrees){
Vector2d control = new Vector2d(x,y);
control.rotate(headingDegrees);
return control;
}
Out of 4 swerve implementations that Iāve personally witnessed, none of them were able to get absolute encoder offsets to behave within 2 weeks. Thereās a lot of little things that make swerve more difficult to implement. For example, few teams know a good way to properly align the wheels to the coordinate system before setting absolute encoder offsets.
And the last one Iāve done, from scratch, took way less time than that.
Thereās some gotchas but itās not insurmountable. With the explosion in software support and example code the last few years itās only gotten easier and easier.
I said the same thing until I started. Took me about a month overallāand that was with essentially full documentation of the 3-month struggle my brother went through last year to do swerve.
Hey I am buying a 3d printer and will get to work on it and other projects. What printer would you suggest. I am fairly new to 3d printing but want something quality I can use to work on projects while in my dorm room. Also Skiddy - have you thought about using metal PLA and print it all in metal for more durability. I do not have any experience with metal PLA so maybe this is not optimal let me know.
Uh⦠NO. This is whatās called unobtanium. You canāt do all metal AND āmetal PLAā simultaneously. And any printer that can do metal at all is going to be far more expensive than just buying the swerve modules. (Let alone material costs.) And itāll have extra steps (typically 1-2 extra units). You thought a Markforged was expensive, you aināt looked at the price tag on a Markforged Metal X.
Itās far more economicalāfor a swerve drive at any rateāto make it on a machine/have it made, than to buy an industrial-grade machine for a dorm room.
Hey eric, I recently reading about a filament that lets you print metal on all 3d printers and was wondering about that. https://thevirtualfoundry.com
That being said. What printer should I buy to be able to print the cheapo swerve from plastic ?Onshape
Thanks Eric
I read about this as well, itās pretty neat. I donāt think youād get the real benefits of metal printing, though, which is stiffness and layer bonding.
Short of carbon reinforced stuff like from a markforged or SLS printer, most of the data Iāve seen shows PLA+ to be the next best structural option (in stiffness and durability). Thereās less data comparing filament types for gears, both for strength and lifecycle wear, though.
Iāve put this module through the ringer with all PLA parts and have yet to have a material failure. The geartrains have all been strong enough to hold stall torque without shearing or flexing. Iām using pretty weak motors, though, and my load cases donāt really mimic FRC play. Iām most worried about the bevel gear for drive, it has kinda thin walls and could flex or shear.
āBack in my dayā⦠that was the quick and cheap way to get a bot that can move any direction. Not a ton of traction for pushing, but it will drift and spin pretty similar to a swerve drive.
And to be blunt, expensive as heck. First print, then sinter, and if you do it wrong or canāt get it to the oven without it breaking, start from scratch. Thatās where we point you to pros.