MODule was a personal project I had to build a highly compact swerve module that is a competent replacement for standard drivetrains, but also a useful, yet cheap omni-directional drive solution for compact robotics. hope yall like it!
OMG OMG OMG I ACTUALLY DID IT SDKFJDSKFDSKJF
Yeah im genuinely so surprised i actually did this lol im stunned
Basically what happened:
I am genuinely surprised i stayed sane after this. I remember starting at like 11 AM and then realized I finished at 7 PM, like I dont even know how I stayed through this long. It was a wild ride, but definitely a fun one.
TOTAL TIME: 8 HOURS
Today was a bit more chill build-wise, but now I had to deal with electrical work and how I can power and control this.
Basically, the main concern was that how I can power the brushed DC motor as I dont have a FTC control hub on me 😔
Sooooo i came up with a few solutions and tested it:
-after 2 hours or so of actually experimenting with power solutions I landed on using 120V AC to 9V DC power brick and connecting that to the motor via jumper wires, and that actually worked really well. 9V meant that it wasnt as powerful as it could have been with 12V, but it was good enough as a proof of concept (i was wayyyy too lazy to keep trying that 😭)
For the servo, this was sooo much easier and was a lot less complex. I had a raspberry pi pico on me and i was able to throw a few lines together to make a quick script that oscillates between two setpoints. The servo is supposed to be powered by a 4.8-7.2 v power supply which is more than the pico’s 3.3v, so I just used the passthru 5v from the USB. this was sooooo much easier than the motor it was actually insane 😭
And for build:
I got my WCP Bearing in!!! Yay!!!!!
I actually got a good bit of my project done lol it was crazy i was locked in
Structure-wise stuff is actually done now, just waiting on printing legion and then illl be ready for the greatest build sprint oat
TOTAL TIME SPENT: 5 HOURS
Ok todays atleast better since I dont have to tap, but now have to actually make this.
For what its worth, tapping actually made the process soo much easier like I genuinely flew through build it was sooo nice and smooth
But still, I somehow ran into an issue.
Most of my parts were printed with printing legion, and that only comes in on friday, meaning Im only going to be able to assemble half of it. Its not horrible, but makes friday so much harder on me 😭esp with recording the video and everything
But other than that, its starting to come out pretty nicely!!!
TOTAL TIME SPENT: 4 hours
So basically i got a motor from my friend to use for this cuz i originally didnt have the money for it, but the problem is that the gearbox on it was HALF SIEZED 😭genuinely took me like 30 mins of prying just to set it free 💀atleast the rest of the disassembly was chill tho took like 1 hour max
After that I had to do something I kinda dreaded: Tapping…
So basically whats happening is that since this was meant to be made out of aluminum, it needed holes to be tapped, but since I wasnt able to use my CNC, I had to print this out of PETG-CF.
Aaand as a result, i now have to tap plastic 💀
The two main things im worried about is:
A. ive never tapped plastic before and am worried the layers might delaminate and separate
B. i have ZERO tapping tools other than just a tapping bit meaning im gonna have to do it by hand entirely 😭
Since im tapping using my hands, this took SO LONG it was actually insane it took me SIX AND A HALF HOURS its wraps for me
TOTAL TIME SPENT: 7.5 hours
So today I got my grant, meaning now i actually have to build this!!!
Only problem is… i forgot to include shipping and taxes lmaooo 170 dollard with of parts now cost 200 bucks lol
AANNDDD i forgot that i actually needed the parts quick cuz im actually trying to submit this for super hardware builder lol
What I did:
On the topic od Mcmaster, I drovethere and did a will call so that iu didnt have to pay shipping so boom money saved
But luckily other than that its going good :D wcp bearing doesnt cost too much but with corgi express shipping it was only 20 bucks and its 2-day!!!
Also my 3d printer wasnt working so I had to outsource to printing legion but its allg should come by friday
At the end of the day, i was able to order everything so im happy about that! Cant wait to start build!
TIME SPENT: 3 Hours 30 Minutes
genuinely a beautiful swerve module
truly a piece of art
cant wait to build it!
so a smooth wheel isnt gonna work i had to actually make tread
i tried doing a few different things, ranging from a bunch of triangles and an extrude to contemplating giving up and using neoprene
i ended uo just taking the pulley profile of a gt2 2mm pulley and extruding it so yea lol
(and yeah now the plates are both light and beautiful)
omg these new forks look so good😍
genuinely idk what i did, but it cooked lol
gonna be a bit of a pain to manufacture but ehh its fiiineee trust
other than that, boom even smaller, genuinely looks like a sandwich atp its actually beautiful
yo no way i forgot we needed an encoder 😭
so im gonna have to change up a few things:
make the coaxial pulley and gear somewhat deadaxle so there is an encoder shaft
ik most teams drop the encoder, but if we want to have the most accurate angle sensing, this is a MUST. we NEED this to have a better swerve module. theres a reason every frc swerve module has this.
other than that tho, its coming together nicely (hes herringbone like i said previously because force spead across multiple teeth)
he is so small 😆
he only need one popcorn 🍿
jokes aside its finally small, time to make it functional. this means make it sompetitive and better than other modules available in FTC. we got the size down, time to make it good and small, not just small.
[tape scratch] yeah thats me. your probably wondering how i got here
but apart from that, i had an idea.
currenty my servo is mounted perfectly horizontal. but why tho? if i mpount it diagonally, ill get tons more space and ill be able to make this even smaller
brains thinging now watch out
i loove back when i didnt know anything about cad and used to vibe guess all my ratios… well now i have to.
so my ideal is the speed of a 435 rpm motor, which is like the commonplace ftc drive motor for mecanums. and my old ratio was like 377 rpm. wayyyyyyyyyyy too slow.
bro im boutta have snail speeds on this robot 😭
i did calculate something, but might need a custom pulley so we’ll have to see cuz i didnt really wanna go to custom pully gang and wanted to stay with cots gobilda pulleys.
My calculated ratios: approximately 855-860 rpm, with a free speed slightly higher than that of the 435 RPM drivetrain motor, a popular FTC choice. although this has a higher surface speed and as a result lower theoretical torque, since the mecanum drivetrains use passive rollers, the grip of these 3D printed swerve tread would more than overpower standerd mecanums.
so yeah now i need to make a wheel for my swerve module and yeah i dont know hoe to make one 😔
i mean I do, cuz like frc swerve, but this is FTC where everything is so small!¡¡ yeah this is small the wheel is 2 inches tall and 1/2” wide lol
finally with something that looks like a swerve module somewhat, i went in, boom. locked in, zero regrets. WE are winning state championships with this.
but yeah, length and width wise its finally somewhat small and usable, so now its time tp make it short cuz its still too tall. the goal is 64mm * 140mm * 110mm so lets get it done.
since axon bevels (THE swerve bevel that everyone uses) is out of stock permenantly, i have to 3dp or use the massive gobilda bevels.
yea. the gobilda bevels are too big. screw it. im making it myself.
so since im 3d printing it, i think making it helical might be the play here, cuz the force is distributed across multiple teeth rather than just one tooth, making the gears stronger and more resistant to teeth snapping.
and yeah, more exams. time to dip for a bit and come back to lock in.
yo no way i just now found out the motor sleeves come off 🤯 this is gonna help so much!
with that the motors diameter gonna be smaller by a tad bit meaning i COULD fit it in a smaller foorprint than 70*140???
the break definitely helped tho i came to my senses that a belt IS the play, talking to seattle solvers helped me greatly.
WHAT AM I DOING NO WAY I DONT KNOW HOW TO MAKE THIS 😔
WHY IS IT SO COMPLEX
WHY
makes me wonder, why gears?
i checked one of the best swerve teams ik’s mosules and theyre using 2mm gt2 belts so might be interesting?
im so used to frc it might be getting to me lol
5000000 million gear sizes, and some of the strongest bldc motors ive seen, which kinda explains why no gt2 belts, so yeah belts…
after losing badly in states (48th out of 48 teams) i knew we had to do something. our old mecanum drivetrain took up so much space we ended up not having enough space for a functional robot 😭
so i was thinking “hm lets make swerve, we can reference other good designs and just make them smaller than a mecanum drivetrain.”
and so it started, me drawing out a bad sketch to present to others my concept, the black box being an approximate sizing of one mecanum wheel’s size and what i think we can do.
idk why, i feel like gears is the move but like its so complicated
also big issue its bigger than the mecanum drivetrain so there really isnt a definitive answer.
well, we gotta do something. i cant be this fixated on a swerve module with FRC season going on and exams afterward. ill take a break and see if that helps.
