Destruction Derby Car Build

Electric cars, trucks, ATVs, NEVs - things bigger than a motorcycle.
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Stevengineer   1 µW

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Destruction Derby Car Build

Post by Stevengineer » Apr 16 2021 11:16am

Hey guys,

A friend and I want to smash cars together in the desert of Vegas, we've built with the M1003 on an older dune VW buggy was fun about 10 years ago, but I wanna make something more like a real-life battle bots - using our FPV quad racing gear and the numerous "FREE" cars on facebook that don't run.

Is there an ideal QS hubmotor for random car conversions? We don't need efficiency or top speed, just fun! :lol:

Also, anyone wanna join us? We're going to need more FPV cars, and I wanna get a 6ft horizontal spinner on one... :twisted:

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neptronix   100 GW

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Re: Destruction Derby Car Build

Post by neptronix » Apr 16 2021 11:29am

QS motors' offerings are going to be way too small for what you're after.

If you're looking for cheap, you may want to look at cloud EV's offerings:
https://www.cloudelectric.com/Motors-s/22739.htm
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

Stevengineer   1 µW

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Re: Destruction Derby Car Build

Post by Stevengineer » Apr 16 2021 1:14pm

I want to make them last longer than traditional ICE Destruction derby's, so I'm trying to do AWD hub motors, it's not as cheap but it'll be more like battlebots on TV.

I'm thinking removing everything from inside of a car, using a 10mile range battery for a battle, and having a super light car after that - no people, just 360 FPV camera and servo controlled steering/motor controller inputs by radio

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neptronix   100 GW

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Re: Destruction Derby Car Build

Post by neptronix » Apr 16 2021 1:23pm

I think the idea is cool but wouldn't have any leads on car hub motors. I know they exist but never entertained them because the high unspring weight would make a car ride terribly.

But ride quality isn't important here. :)
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

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nicobie   1 GW

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Re: Destruction Derby Car Build

Post by nicobie » Apr 16 2021 2:09pm

GREAT idea! But it's going to be expensive. You really need a sponsor or two. In the past Lucas oil has been good to me. The tires guys are usually good for a few free tires/year for the race car or tow vehicle.

I could see this ending up on TV.

🏁🏁🏁
Ask for it by name.

my eTownie build thread: http://endless-sphere.com/forums/viewto ... =6&t=23701
Magazine article https://www.electricbike.com/nicks-etownie/

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neptronix   100 GW

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Re: Destruction Derby Car Build

Post by neptronix » Apr 16 2021 2:13pm

Yeah i'd watch that shit. You could probably get away with using cheap recycled electric car batteries too. Lots of Nissan Leaf and Chevy Volt batteries being sold in modules for nearly nothing out there on eBay.
"Love and compassion are necessities, not luxuries. Without them, humanity cannot survive." - Dalai Lama

My first major build: 1.6kW 8T MAC motor on a Trek 4500 MTB.
Monster MTB: Leafmotor 1500w @ 4kW on a Turner O2 full suspension.
The monster scooter: Heavy duty Cannondale semi recumbent - under construction.
Blue Dream: Maxaraya FS semi recumbent and high efficiency mid-drive - under construction.

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fechter   100 GW

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Re: Destruction Derby Car Build

Post by fechter » Apr 16 2021 2:39pm

Just get the whole power train from a Leaf or other available EV. Maybe find one that was rear-ended. The batteries on those are the first thing to get recycled, so I'm sure you'd have to find a battery separately. If you only need 10 miles range, a much smaller battery will work.

No matter what, it's going to be a fair amount of work to convert a gas car to electric. It will be pretty disappointing if the car dies after the first hit.
"One test is worth a thousand opinions"

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nicobie   1 GW

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Re: Destruction Derby Car Build

Post by nicobie » Apr 16 2021 3:09pm

Even though I hate them, ½ a ton of garbage lead acid might be all you need. In demolition derby weight is to your advantage... once you get the car up to speed.
Ask for it by name.

my eTownie build thread: http://endless-sphere.com/forums/viewto ... =6&t=23701
Magazine article https://www.electricbike.com/nicks-etownie/

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everythingisawave   100 mW

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Re: Destruction Derby Car Build

Post by everythingisawave » Apr 16 2021 6:00pm

Would definitely like to see this on YouTube.

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amberwolf   100 GW

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Re: Destruction Derby Car Build

Post by amberwolf » Apr 16 2021 10:55pm

neptronix wrote:
Apr 16 2021 11:29am
QS motors' offerings are going to be way too small for what you're after.
I dunno about that. They have some 12kw hubmotors for cars, and that's 12kw *continous*, so you could probably do several times that peak. (they state double peak on their page; I'd bet it will do more based on what others have done with bike-style hubmotors)
https://www.qsmotor.com/product/12kw-car-motor/
Put four of those on there for AWD and.... ;)

More
https://www.qsmotor.com/car-motor/

Controllers will be expensive....


You will need to protect the wiring, so ti won't get pinched / crushed and shorted in collisions. Routing it under the car along the frame will probably help; you may need to deliberately route battery positive and negative as far apart as practical for as much of the runs as possible, to ensure they cant' be shorted out. (fuses, breakers, etc will help but only by cutting power--if you don't have to cut power it's better cuz it'll run longer ;) ).

Protecting the battery itself...put it in with the driver, in the roll/anticrush cage? Center of mass of vehicle for better performance? But "firewall" it so if something does go wrong the driver has a half a chance of getting out alive if not completely undamaged.

Stevengineer   1 µW

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Re: Destruction Derby Car Build

Post by Stevengineer » Apr 16 2021 11:12pm

amberwolf wrote:
Apr 16 2021 10:55pm
neptronix wrote:
Apr 16 2021 11:29am
QS motors' offerings are going to be way too small for what you're after.
I dunno about that. They have some 12kw hubmotors for cars, and that's 12kw *continous*, so you could probably do several times that peak. (they state double peak on their page; I'd bet it will do more based on what others have done with bike-style hubmotors)
https://www.qsmotor.com/product/12kw-car-motor/
Put four of those on there for AWD and.... ;)

More
https://www.qsmotor.com/car-motor/

Controllers will be expensive....


You will need to protect the wiring, so ti won't get pinched / crushed and shorted in collisions. Routing it under the car along the frame will probably help; you may need to deliberately route battery positive and negative as far apart as practical for as much of the runs as possible, to ensure they cant' be shorted out. (fuses, breakers, etc will help but only by cutting power--if you don't have to cut power it's better cuz it'll run longer ;) ).

Protecting the battery itself...put it in with the driver, in the roll/anticrush cage? Center of mass of vehicle for better performance? But "firewall" it so if something does go wrong the driver has a half a chance of getting out alive if not completely undamaged.
Great tips! Thanks!

I wonder if there's a way to deal with losing a wheel without shorting and stopping the rest of the car from working... I could always use multiple batteries and keep each hub motor separate like some BattleBots guys do, and then more easily protect the control circuitry that tells motors when and where.

There won't be a driver, we're going to do VR with RC. This is Battlebots-Cars, I hope anyhow, it'll be slow to start, and then to get my other friends around the world to join in... but I know at least 3 groups that will hopefully join the fun once we start it.

It won't be cheap, no, I should start a Patreon page :mrgreen: Anyone wanna spare some dogecoin?

The goal is to have fun! I'm tired of things that move normally, lets do a barrel roll! :flame:

Stevengineer   1 µW

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Re: Destruction Derby Car Build

Post by Stevengineer » Apr 16 2021 11:28pm

what would be better guys?

4 motorcycle sets (so the wheels can be chewed and the motor survives sometimes) : https://www.aliexpress.com/item/4001212030238.html

or

4 normal hub motors and just add protection to wheels like some battlebots: https://www.aliexpress.com/item/4001278399625.html

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fechter   100 GW

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Re: Destruction Derby Car Build

Post by fechter » Apr 17 2021 11:18am

Those wheel motors don't look too bad. 8kW each should at least move a car. A very stripped down, lightened car would go a lot faster. For sure those would be the most flexible for mounting and could work on almost anything.
"One test is worth a thousand opinions"

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