Future crawlers? Is this possible?

[toyotatrucks83]

I was thinking back to when I was in school. We built a hydraulic car using hydraulic 4 motors. One at each wheel. This made me think about using those height torque outrunner brushless motors in the wheels of the crawler. It would be like the natural progression to MOA. MOW (motor on wheel)
With all the quad copters become available and so cheap I kind of figured technology maybe cheap enough to start building crawlers like this.
Any thoughts, suggestions, anything?

[killswitch]

I have no idea about your questions... the only thing I could think of when I read your thread title was 1.21 gigawatts.

[toyotatrucks83]

Lol. It kind felt that way while writing it.

[BDR]

It was tried in the 1:1 world of crawling

Was impossible finding something powerfull enough, in a small and light enough package

Dare say it would be the same in RC crawling, but by all means go find out and report back, just don't tell the wife how much you spent

[killswitch]

I would think it very difficult to find 4 motors that were matched in RPM and power. If you don't have matched motors, it's going to be hard to drive it in a straight line because the motors are going to fight each other.

[bigstu]

Not to mention there isn't a motor that doesn't need some sort of gear reduction.

[toyotatrucks83]

Gearing is a good point. I thought gearing might become obsolete. With super low kv motors and only needing to power one wheel.

[losikid]

I have electronics and drivetrain figure out...but not sure on suspension and steering, lots of ideas, but none seems like it'll improve whats out there now

I was told it never work and blah, bla blah...back when i first joined, so its been my little side project

I don't think its easily doable in a 2.2, but i got plans that'll work great in a super sized crawler.

[toyotatrucks83]

Super cool losikid. Were you able to run it on a flysky gt3b? I imagined with independent drive on every wheel you'd just run independent suspension as well. But we are talkif all new stuff here and what is on the market as a Moa and such probably work better. Just new ideas.

[JohnRobHolmes]

I conceptualized a motor in wheel design in 2007. Motors have to have the gear reduction or else have a bazillion poles. Even with high poles some reduction is handy. I too think super class would be the place to do it.

Possible, yes. Easy, no. Worth it, nobody knows yet.

[losikid]

Originally Posted by toyotatrucks83

Super cool losikid. Were you able to run it on a flysky gt3b? I imagined with independent drive on every wheel you'd just run independent suspension as well. But we are talkif all new stuff here and what is on the market as a Moa and such probably work better. Just new ideas.

I haven't actually built one, just plans for drivetrain and electronics.

I want todo independent suspension, really the biggest possible gain with a MIW (Motor In Wheel). BUT, solid axles crawl better, from what i've seen. The next major gain is "turning brakes", which could also have similar affects as dig, traction/suspension wise. But i'm not sure how much more it'll give compared to plain ol dig

Originally Posted by JohnRobHolmes

I conceptualized a motor in wheel design in 2007. Motors have to have the gear reduction or else have a bazillion poles. Even with high poles some reduction is handy. I too think super class would be the place to do it.

Possible, yes. Easy, no. Worth it, nobody knows yet.

Damn you got me beat, i was thinkin about it 09'...but i got started into rc in 09'

We talked afew years back about the electronics too...sensored brushless is the key electronics wise i think...once you get your brushless stuff going, i can get back to thinking about it some more

[rockhugger]

Originally Posted by JohnRobHolmes

I conceptualized a motor in wheel design in 2007. Motors have to have the gear reduction or else have a bazillion poles. Even with high poles some reduction is handy. I too think super class would be the place to do it.

Possible, yes. Easy, no. Worth it, nobody knows yet.

Originally Posted by losikid

I haven't actually built one, just plans for drivetrain and electronics.

I want todo independent suspension, really the biggest possible gain with a MIW (Motor In Wheel). BUT, solid axles crawl better, from what i've seen. The next major gain is "turning brakes", which could also have similar affects as dig, traction/suspension wise. But i'm not sure how much more it'll give compared to plain ol dig



Damn you got me beat, i was thinkin about it 09'...but i got started into rc in 09'

We talked afew years back about the electronics too...sensored brushless is the key electronics wise i think...once you get your brushless stuff going, i can get back to thinking about it some more

Dont' think, Do

Just kidding, but it sounds like a collaboration project for LK, JRH, & Heyok perhaps.

I'm sure you guys have seen this contraption already
Green Dawg an Extreme Machine_KrawlZone.tv - YouTube

and this one is not electric, but similar idea
Chainlink extreme 4x4 Lizard - YouTube

[Olle P]

Originally Posted by JohnRobHolmes

Possible, yes. Easy, no. Worth it, nobody knows yet.

I agree with this! One problem is motor control, having each motor run at the correct speed even if one or two wheels slip while the rest have traction.

I know that it has been done in a race type R/C car not many years ago.

[monkeyracing]

This wasn't the first, but it was a good one. The Apollo Lunar Roving Vehicle

The electronics are relatively simple for this kind of thing. Getting small motors with boatloads of torque is the trick. Given the progression of brushless technology in the past 10 years, I'd say we're not that far off.

[losikid]

Originally Posted by Olle P

I agree with this! One problem is motor control, having each motor run at the correct speed even if one or two wheels slip while the rest have traction.

I know that it has been done in a race type R/C car not many years ago.

This isn't a problem, i already got it figured out

[KJ10]

MOW is correct, however, it needs to stand for "Motor Over Wheel." Portal style.

AxleTech International Motorsports 0001528A01 - AxleTech Motorsports Portal Axle Kit for Dana 60 Steering Axle & GM 14 Bolt Rigid Axle - Quadratec

[KJ10]

Originally Posted by losikid

This isn't a problem, i already got it figured out

John Holmes will also sell balanced motors so I don't see that as much of a problem, anyway.

[JohnRobHolmes]

Velocity loop controls are one way of balancing the wheelspeed, but the slipping nature of motor on axle or motor in wheel design is a good thing. It won't need to be balanced. It will be handy to power bias though. Skid steer, dig, 3 wheel, anything is possible. It won't really be necessary to have steering servos, but they will increase maneuverability.

[losikid]

Originally Posted by JohnRobHolmes

Velocity loop controls are one way of balancing the wheelspeed, but the slipping nature of motor on axle or motor in wheel design is a good thing. It won't need to be balanced. It will be handy to power bias though. Skid steer, dig, 3 wheel, anything is possible. It won't really be necessary to have steering servos, but they will increase maneuverability.

For crawling, you'll want to be able to turn a wheel to search for grip and all the other nifty stuff steering can help with...

[losikid]

Originally Posted by KJ10

MOW is correct, however, it needs to stand for "Motor Over Wheel." Portal style.

AxleTech International Motorsports 0001528A01 - AxleTech Motorsports Portal Axle Kit for Dana 60 Steering Axle & GM 14 Bolt Rigid Axle - Quadratec

My design has the motor in the wheel