Raptor II: MK1 - Hardware Update

[@thehardwareguy]

Watch Raptor II in action: kzbin.info/www/bejne/mYqzfpegZdWWjqM

[@pet_ti]

This project deserves some more views. So here is a comment: Nice project!

[@Jrod_FPV]

I really love this project because there are so many possible applications! Mostly from the controls side as the mechanical side here is already figured out and done well by off the shelf rc cars. application 1 - RC rock crawling - Controls - being able to control wheel speed individually offers huge benefits in traction and tight turning radius. Rock crawlers would benefit by the front/ rear individual speed controls, as well as left/ right. Another idea i had is to make the wheel out of the outrunner brushelss motor. This would put the motor weight lower, which will have huge center of gravity benefits and prevent the truck from flipping during steep climbs/ descents. application 2 - high speed track car - control of wheel speed on individual wheels would result in huge stability and turning benefits. I would assume high speed cars would only benefit from the left/ right individual speed control and not so much of the front/ back. Your steering issues/ complaints. - 1 - You are very analytical, much like me. Have you done drive testing on the steering issue? Or is it just from bench testing? I've made the mistake many times where i think i see a problem with something during bench testing, only to find out there's really no issue at all while using it in the field. If you've ever taken the propellers off of a drone and armed it on the bench, you know what i'm talking about. 2 - I agree, the simplest, least play/ backlash / hysteresis is going to come from eliminating the steering link. Have you studied how production RC cars work? Most of them do have some linkage, which is no big deal, just keep in mind you can use the geometry to keep it from having too much play. 3 - keep in mind if you direct drive your steering with the servo, when you crash, it's going to destroy either the link, or your servo gears. I would recommend finding an existing servo saver from existing RC car and re-using it. Or copying the design. 4 - All that said, I think you could do away with the individual wheel steering but that's because i think the ability to control the speed of each wheel individually is value enough on its own. Have you had a chance to look into FOC ESC's ? may remove the need to have encoder sensors at the wheels. less sensors, less wires, less programming?, less mess/ wire management. You may benefit from using a drone flight controller running flight control software called betaflight. It would be a shoe horned application but i think you could start out by using it directly, then create your own fork for a driving (instead of flying) specific application. I can't believe someone hasn't done it already - maybe it exists and i don't know about it? But it's crazy to think how similar the control logic would be in flying a drone vs driving a car with seperate controls for wheel speed. Each has 4 motors, each would use a control loop and gyro sensors to modify the motors output.... man it would be so cool ! if you're interested i can send you a link to a flight controller.

[@kschaub62]

Love this project. The work you are doing is incredible!

[@nakfx134]

Im glad I found your video, Im currently working on a similar project! Love your work!

[@twinturbostang]

Might consider adding a servo-saver. If the wheels take a big hit, it could damage the servos. The downside is the servo saver may add a little bit of slop, which you're trying to get rid of.

[@TheTotalGeek]

Hey just stumbled across your channel. Nice work! Looking forward to seeing how your rc buggy turns out. I will be going back to watch your guide on printing 3d grear :) Cheers!

[@avejst]

Looking great ☺️ Thanks for sharing your knowledge to all of us 👍😊

[@harrysherwood9439]

Very cool project!

[@thehardwareguy]

Thank you!

[@DIYTinkerTech]

Keep up the great work!!!

[@mikealgarvin8122]

Great project

[@The_Engineering_Boost]

Why do you have a servo for each wheel for steering? Why not use one servo to control both?

[@nicholaskerslake3936]

kzbin.info/www/bejne/iqmumZxshtilpck this video explains toe angle and what it does

[@nicholaskerslake3936]

I already thought this was an awesome project and then you went and added DAS! well done mate! what are the specs of the motors/ ESC's/ battery you're using? I also want to ask if it would be possible to use a drone flight controller rather than an STM32 board? the reason I ask is that drone flight controllers are already designed to output to 4 motors plus there are other outputs that can be used for servos and it's super easy for simpletons who don't know how to code (such as myself) to set it up with open source software in a nice GUI like Betaflight or Raceflight etc. I think it'd be such a game changer for RC cars if something like that caught on!

[@adrianhardcastle9297]

Awesome! have you not thought of putting the front bell cranks onto a fixed pillar with a spring above (ie, servo saver style) direct drive with servos may strip them (even metal geared ones) and you can then keep the servos inboard for water proofing - if you build a beast like this it has to play in the mud/snow! ;-) Also you have no diffs - guess thats an engineering choice - are you compensating for that in the engine management? (apologies if this was in an earlier vid I've just stumbled across this project) Or you going slow enough not to bother? or with your engine management I guess you can choose? Oh and your telemetry is next level for an RC dude...

[@FabrizioManzo-me2tq]

Great job! I do have a question: how do you achieve negative (braking) torque in the engine? In other words how can you slow down the vehicle? Do you mount / program a particular ESC able to do that? Thanks a lot!

[@thehardwareguy]

The ESC's I used have braking functionality, it'll say how to program it in the ESC Manual. I didn't implement this on my car as I just wanted to be flat out almost always

[@FabrizioManzo-me2tq]

@@thehardwareguy thanks a lot! It means that by writing code in the stm32 you are potentially able to make the engine braking, correct?

[@thehardwareguy]

Yes!

[@rockingjithin]

nice work

[@joske7804]

Comment for algorithm. Awesome stuff.

[@ondrejcakan3298]

Looking forward for real ride test ... Those wheel arms looks too thin for me .... How much current it takes when spinning all wheels ? Would be just one battery enough ?

[@ShortTheRick]

Motor running, when turn the light on, or the servo moving,... the motor will be slowed down (perhaps, voltage drop). Is the power distribution board can fix this problem? I'm not sure what to find.

[@robovsesvit]

Thank you very much for you excellent work! I'm begineer in this robotics sphere, and I want to make your project! Amazing! Do you have a some videos, how to assamble step by step?

[@aksabelajar5925]

are you sharing raptor II 3d model to your website member?

[@de-bodgery]

I get that this is an engineering project. BUT!!! You said it..."over complicated it a bit". I''d say every aspect is overly complicated. A single motor and ESC could have driven all 4 wheels. Small diffs exist so that you can transfer power to the outside wheels or even limited slip. All you needed was a single servo for all of steering. Part way into this video I was wondering if you had been taught the KISS principle!

[@makewithmegma]

🔥😍👍

[@Corruptlol187]

I think you should go for some sort of sliding rack like it is used in drift cars. And I m pretty sure you can't keep the car with that amount of 3d printed components, you have to cut stuff carbon or aluminium otherwise it will explode in pieces on the first proper run ( not Walking Speed around the backyard )

[@felixkreider304]

LOL first