2m diameter wheel inflatable car-ish build!

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Dec 3, 2018
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Im building an all terrain vehicle based on 4 concrete mixer motors, each one connected to huge inflatable wheels.
Feel free to subscribe on youtube and join me in the exciting creative learning process! First episode:
https://youtu.be/24uW2Rwwi6k

https://endless-sphere.com/forums/download/file.php?mode=view&id=241559
 

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First successful test. Im very conservative on the throttle for obvious reasons, but it looks promising so far.

[youtube]G8WcXCmEySk[/youtube]
 
Love it! Nice job!
 
Ive been watching and suscribed for a while, it's the manned quadcopter that caught my eye.

I like this build it's crazy but efficiency will be an issue.
Personally I'm a fan of hoverboard wheels for the price, they have a very low kv around 13 and great torque but with such a increase in wheel size to 2m from 8 inchs even their low kv will give a high top speed and a big torque reduction, so id run them from a vesc to control rpm and use one or maybe two on each wheel so there's good power from them and direct drive no gears to chew under heavy load and a big weight saving.

The vescs can be linked through can and traction control can be implemented and a limited slip diff to get it climbing like a beast and with the slippy wheels I imagine this would be what's makes a good climber an excellent ride that will go over all the bushes and hedges no issues.

Top work with the channel and look forward to future content it's nice to see creators reach out.
 
Unlucky on the broken rivet, not a perfect test run but productive better to see the faults early on so a fix can be implemented.

I still think the hoverboard wheels are the way to go they could be slotted in a sleeve and bolted in place with a m10.

How do you plan to get it to turn better more accurate speed control ?

All the footage is excellent can really work out what's happening keep up the work I'll keep watching.
 
First of all. Old thread but Amazing project!

I have been thinking for awhile to built vehicle like this. Biggest concern of mine is how the wheels will last and how expensive those will be to build (some pvc fabrics that I looked at 600-900g/m2 were +500€ for the required 2.5x20m piece to cut 8x2.5m circles). On water it must last forever but on land if grass field has some sticks and stones..

For drive train I was thinking about hoverboard motors because prize/weight/rpm and since +200v batteries are not something that I want to get into. direct drive would be nice but probably not enough torque and 200km/h top speed is just out of question so some reduction is needed. maybe something like this: https://www.ebay.com/itm/5M-HTD5M-60T-15T-Belt-Width-20mm-Timing-Pulley-Belt-set-kit-Reduction-Ratio-4-1/263561823742?hash=item3d5d8245fe:m:mCjn5fAmhK9L_lHc2YncvDQ&var=562605482694 It will be pain to mout to hubmotor but I think it will work if it can handle that torque.. Some cheap 1kw 48v motor controllers or maybe using hoverboard logicboard if that works.

Does anyone have suggestions how to make this idea even better? My main goal is to explore nearby small lakes. Thouse are very shallow and a lot of grass and rocks so for boat its not pleasant ride and I love the idea that this kind of vehicle could work even when ice on top of the lake is too thin to even walk on. :)(Last winter here ice was too thin for whole winter :( )
 
Rewind comes to mind but there's problems in getting the low kv and maintaining good torque.

The motor needs at least 4× the amount of turns to slow it down to a kv that is usable in the 2m diameter wheel at 48v while being able to keep the cross section diameter of the copper thick enough to maintain a decent current.

If one motor was being used I'd say no way but the fact there is four says to me it's with in grasp,
2 ways about it rewind for max power get 2000 watt to the wheels by settling for a voltage and wind that keeps the same copper mass as before if not a little more to keep the original hubs wattage throughput of about 350-500watt max but bring that kv down, possibly change the circumference of 2 meters aswell to give a little helping hand as the ride is huge.

Second way is to undervolt the hub and deliver it's original current the motor will still pull strong but you will be limited to it's original current throughput get about 350watt per wheel 1200 total.

Got to say driving up the lake seems fun and it looks a blast going on and off land thumbs up to the original.

I've had hub motors on a vesc and give them a dabble and got about 800rpm at 12s, so on 12v it would be ok limit the current to 30amps so you get about 350watt through each motor and run all 4 like that would see it move around with about 1200watt to the wheels.

Good thing with 12v is there no shock protection needed it can be submerged with a human and be fine 48v is fine in open air but if your wet under water etc it will shock you.
 
Wheel diameter and voltage are something that could be easily changed. Rewinding 4 motors seems like lot of work and something that I have not done before. Could I get 2 or 3 times torque out of rewound motor like from gear reduction? (at same phase amps) Probably not.

1.5m wheel diameter is still huge but easier for motors and apparently my wallet :roll:. Not sure how much power I really need since its not suppose to make burnouts on paved roads but it would be nice to have descent torque so everything has little bit headroom in normal operation conditions. If 3 of the wheels are on water and only one is going out from lake to uphill it needs certain amount of torque and power even if the max thrust in water could be 100kg with original vehicle design.(Likely @1.6kw per wheel..)

As for voltage. 48v gives more power and speed but lower may be better in this case. At 36v motors still have descent power but downsides are likely same as 48v. 12v means very low power or a lot amps and copper for long wires unless I have 4x batteries also. Only way to be sure might be to build it and test. If performance is poor then decide between rewind and reduction.

What is considered as upper limit of "safe" battery voltage to take with you for a swim? :lol:

Inflating tires is also something to consider. If 2 vacuum cleaners can keep then topped of @230w combined with pwm control I bet 1 of them can do it @half power and something else with even less effort. Maybe something that is meant for rc aviation or from battery powered vacuum/blower? Voltage comes again to be considered with this unless powered from different battery. Flow also has to be high enough to fill tires in reasonable time.

I really would prefer 36v or 48v since I already have some 10s and 14s batteries but for range I have to buy more anyway..
 
Old battery dyson proberly give the airflow needed without to much farting about they operate at 5s 22.2v plenty of spares or repairs old models about with dead batterys keep the build cheap.
Stock the hoverboard motor has enough power to power a scooter to 20mph on its own but has a kv rating of about 16 where you need crazy low around 4 or less.
One thing to think about is the displacement needed for the total weight if it can be kept low that will allow a smaller wheel more suited to the hub design keep it slow moving.
Breakdown voltage of skin in open air is differing for each body part depending on moisture content finger tips are dry takes about 48v or more to start feeling a tingle but a 9v battery across your tongue gives a tingle so 48v underwater can give a decent tingle.
 
Original vehicle according to video weighs 119kg. Not sure if its with or without batteries. Some of it can be reduced but assuming its 2 person vehicle (It would be nice to go to lake with friend) -10 or 20kg don't matter that much and anything more seems unrealistic with cheap materials and hoverboardhubs.

I have no idea how much 1.5m wheel has less effective displacement than 2m but I assume it can be easily compensated with just a little wider profile. It should not sink that deep and only surface area that sits against water matters. Right?

I feel that right thing to do is to use reduction even when it adds little weight and mechanical complexity but its just so much easier for motors and controllers.
 
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