Motorized wheelbarrow

[Callipygous]

This is a bit outside the realm of go karts, but all the stuff I am having trouble with seems like it would be right up your alley, so I thought I'd give it a shot.

My favorite regional park has a very unfortunately placed road, which has made it a dumping ground for the less scrupulous. Basically a road follows the main creek, so every time it does a hairpin turn, if you just look down in the ditch you can find tires, paint cans, batteries, endless bottles, a few truck "gem tops" and even the bodies of one or two small cars. Between the slope and periodic torrential rains, this basically means the entire creek is full of trash. I took it upon myself to try to clean some of it up, and built a one-wheeled cart to haul out all the trash. The problem is that every little rise on the trail,though almost unnoticeable while hiking, becomes a major hurdle when you're pushing a couple hundred pounds of tires. So I think my next best bet is a wheelbarrow with a motorized wheel.

Things I'm pretty sure about:

1 wheel. the trail goes down to single track, and though it would be more stable, I just don't think 2 wheels are going to work, unless they were sandwiched so they are only about 10 inches wide.

Electric. The idea is that I will be coasting on the flats and downhills, and want to be able to kick on the motor when I hit an uphill and need some umph. I don't want to have to stop and start up a gas motor, I want to just pull the throttle and have power show up when I need it. I like the idea of having maximum torque at 0 rpm. And lastly, its a regional park, people are hiking. I don't want to be the dude out there running a two-stroke ruining everyone's afternoon. I'm also not sure it would be allowed.


Things I don't really know about:

How much power do I need? I think I can reasonably balance around 250 lbs in a wheelbarrow. Trails are usually kept under 10% grade for erosion issues. I tried to do some basic calculations based on a formula I found on a go kart forum (might have been this one, I don't actually remember) and I came up with around a 300-350 watt motor, but I'm hoping someone experienced can let me know if that seems right.

Because coasting downhill and flats, I guess I need a freewheel somewhere in the drivetrain, but I don't really know how to put any of that together.

Gearing. I am looking at a top speed of around 2-3 mph. It seems like most electric motors are designed for scooters, go karts, things that are moving 15-60 mph. I know this often involves an electric motor that is revved high, and has a small gear, which then drives a much larger gear, but it seems like I need it geared down much more than that. I don't know if there are electric motors that like to run slower, or if I need to just use some kind of gear arrangement, and how I would make all that work.

Any tips and suggestions would be appreciated.

 

[Ebrownie]

Welcome! We have a few electric experts around here that should be around at some point, but I am not one of them. I can tell you that you will have to gear this very low. You might be able to use a gear reducer of some sort to help you out.

You also have to take into consideration that batteries are heavy. I think that if you got 2 wheels and put them right next to each other, you would get more stability. Picking up 200 lbs of junk after it tips over won't be fun.

 

[Bbqjoe]

Electric?
1 wheel?

Faggetta about it.

 

[Callipygous]

Yeah, I know batteries are heavy. I've been shopping around and figured I would probably end up with 3 of the 3"x3"x6" 12v batteries, though I can't find mention of what they actually weigh. 2 wheels stacked might add stability on even ground, but what I have found is when you go over something that is very uneven, so all your weight shifts from one wheel over to the other that can actually be harder to balance than if you only had one point of contact. with a car, or go kart, you just let the wheels follow the terrain and the whole thing kinda tilts back and forth, and that's ok as long as it doesn't get too extreme. With a wheelbarrow, if I have two stacked wheels, and I go over terrain that is a few inches higher for the left wheel than the right, that means my right arm has to do all the work of keeping the weight centered over the tire, I can't just let the whole thing follow the terrain because the center of mass can much more easily move outside the wheelbase.

 

[itsid]

I doubt 350Watts are going to cut it tbh. without actually calculating...

Anyways, there are motorkits designed for wheelbarrows (highly geared down motors with single or dual wheel drivetrain)
most simplistic version is essentially a wheelbarrow wheel (with built in motor gearing and controller)
it's on alibaba for sure.
Add a battery, a small pushbutton and mount all of it to your wheelbarrow and call it good.

thing is, that's quite some load, and not the easiest terrain as you described it.
I think you'll need to beef up.
I'd say two wheels (one nasty pothole and you're stuck for good.. or worse can watch it all tumble back downhill again)
you can have the axle pivoting (between two extremes if you like) so that a slanted path can be tackled as easily as with a single wheel.. in fact easier since you only need to have the COG between the two wheels, not in the center of one

crank up the wattage.. 750 Watts or so I think are more likely what you want;
not because you could go faster, but because it'd provide the power to climb out said pottholeand wouldn't overheat too easily going up the inclination for an extended period of time.

And now the downside, I'm not sure there is a ready made kit for you to buy,
I think you'll indeed have to make one.
but fear not, it's not actually rocket science.
you could for example source a transaxle from a wheelchair, or just buy two of the afforementioned motorized wheels..
whatever feels good for you.

Oh one more thing:
NO freewheeling!
instead find a regenerative braking controller for your motor.
that way going downhill will refill your batteries and even better slow down the barrow slightly
(you wouldn't want 250lbs to catch some speed and go berserk on you, would you?)

'sid

 

[Callipygous]

thing is, that's quite some load, and not the easiest terrain as you described it.
I think you'll need to beef up.
I'd say two wheels (one nasty pothole and you're stuck for good.. or worse can watch it all tumble back downhill again)
you can have the axle pivoting (between two extremes if you like) so that a slanted path can be tackled as easily as with a single wheel.. in fact easier since you only need to have the COG between the two wheels, not in the center of one

That all sound delightfully fun, but I was not feeling confident enough to put together a standard drive train on my own, never mind figuring out how to implement a pivoting axle. Is this a thing that can be learned reasonably easily? Like, I get the gist of how a drive train would work, its the specifics of designing and building one... wouldn't know where to start.

crank up the wattage.. 750 Watts or so I think are more likely what you want;
not because you could go faster, but because it'd provide the power to climb out said pottholeand wouldn't overheat too easily going up the inclination for an extended period of time.

Again, sounds great, but based on my understanding of the formulas (which I think were sourced from your post btw) it seemed like 750 watts puts me in the range of either a crap ton of batteries, or about 30 minutes of run time. Have I miscalculated?
750wattsx1.25 (to convert from mechanical power to required electrical power?)=937
937/48v=19.5 amps. So if I used 4 12v 12ah batteries, that gives me 12ah at 48 volts, which means .61 hours of run time.

NO freewheeling!
instead find a regenerative braking controller for your motor.
that way going downhill will refill your batteries and even better slow down the barrow slightly
(you wouldn't want 250lbs to catch some speed and go berserk on you, would you?)

I had no idea such a thing existed, but neat. My plan had been to use a mini-dirt bike rear wheel assembly, complete with sprocket and disc brake. I was thinking of maybe finding a way to set it up so the brake was engaged unless I was squeezing it, rather than the other way around.

 

[Rail rider]

Look into E-bike crank motors you can set the speed with a potentiometer. And fire it up with a non lighted door bell at the thumb hold area... Those 3×3x6 batteries are free at the home depot battery recycle bin . I have a few from there.

 

[Callipygous]

Free, but in need of some repair, I assume?


Also, whole thing might come to a screeching halt anyway. My contact at the park district is telling me no motorized vehicles allowed. I know they make exceptions (disabled people, the hunters they hire to remove invasive pigs, caterers in certain parks, and the rangers themselves all drive some sort of vehicle on the trails) Seems like cleaning up trash that would otherwise be mostly unmanageable should fall into the "exception" category, especially if my top speed is like 3mph. It might take some talking though...

 

[itsid]

Well, a wheelbarrow is not a vehicle, is it?
you move stuff, not yourself. It's more a powertool than a vehicle really

Anyways,
pivoting axle.. do you think you could build a seesaw?
you think you could turn it upside down?... replace the board with a transaxle off someone else's shelf (electric wheelchair)?
See? no rockets involved, some minor welding, some bending perhaps, a bit of drilling and some nuts and bolts.

Now, yes, if you run the 750W motor at full power all the way, you'll need a lot of batteries.
BUT if you throttle the motor to say 50% it uses about the same juice a 350W motor would;
and it still runs cooler than the 350W motor plus it'd be able to climb those sticks and stones
on the way with just a push of the thumb.
talking about thumbs:
THUMBTHROTTLE! no doorbell crap, no redneck engineering... a 5 dollar thumbthrottle for electric scooters of ebay.. the proper part for the job, cheap reliable and as easy to source.

Batteries are nasty still...
first my calculation in that other thread is basically worst case.. "full throttle till it's drained"
so it returns the lower limit only.
everything else is unlikely to be calculable you'd need to know the exact terrain how many logs and stones to climb, what power would be needed under what load, the drag of muddy paths perhaps etc. pp.
So worst case.. full power all the time.
You know you carry ~200 lbs less for half the journey, half your pilgrimage is downhill,
and most of the rest will not need full motor power.
So I think you can assume that you might get twice the time out of the same batteries without even trying too hard
But again, this needs to be tested to know for sure.

If you really need really long running times you might be better off using a combustion engine
then again.. I think combustion engines are exactly what they do not want in the park.. *shrugs* (noise, gasoline, exhaust fumes...)

talking about this... ask the administration if they own a minihauler for such tasks;
maybe they do, maybe they allow you to use it in order to clean up the park.

'sid

 

[Bbqjoe]

You could just leave the tires where they're at, then deal with them.

 

[itsid]

I stumpled upon this wheelchair powerdrive:
http://www.skycraftsurplus.com/ez801-t02bmotorwheelchair24vdcwbrake.aspx

40 bucks.. 24V and all the drivetrain you'd want.
since it's a wheelchair part I'd assume the net weight of a typical wheelchair user can be hauled
and these things are meant to primarily run at "walking speeds"

unfortunately, that's AFAIK a 75Amp motor (i.e. 1800W electrical power [for few seconds only]) it'd still need a matching controller to run it properly;
and since it's a wheelchair motor you'd need some extra fiddling with the internal brake and such.

Still, at that price it's a marvellous starting point for the task at hand IMHO
so I thought I'd let you know

'sid

 

[Callipygous]

This would be the regulation in question.

SECTION 902. - OPERATION OF MOTOR VEHICLES; OFF-ROAD VEHICLES.
902.1  General. Except as provided in section 902.3, no motor vehicle as defined in section 902.2 may be operated within District Parklands except on established paved roads which are open to the public. >(I) (rev. 4/16)

902.2  Definition. A motor vehicle is any vehicle or device that is self-propelled by means of an internal combustion engine or electric motor, used to transport a person or property. Motor vehicles include, but are not limited to passenger cars, motorcycles, off-road vehicles, "dirt-bikes," all-terrain vehicles, motorized skateboards, "Go-peds," motorized scooters, self-balancing electric scooters aka "hover boards", "Segways," and similar vehicles. (rev. 4/16)

902.3  Exceptions.

a)
This section shall not apply to authorized emergency vehicles.
b)
This section shall not apply to areas, roads, trails, or paths which may from time to time be set aside or posted by the Board for the use of specifically designated vehicles.
c)
This section shall not prohibit the use of gasoline or electrically driven golf carts upon golf courses within the District parklands.
d)
This section shall not apply to electric powered wheel chairs, electric scooters, or other power-driven mobility devices used in conformity with the District policy on use of other power-driven mobility devices, while being operated by a person with a medical condition or mobility disability, which impairs normal mobility. (rev. 4/16)

I feel they would be hard-pressed to convince me that other people's garbage is "property" but they are the ones with the citations, not me. I also like being on good terms with them, so it is ultimately down to their decision. I feel there must be some way to get a special permit or something. I know the hunters use ATVs to haul in cages and haul out carcasses.

then again.. I think combustion engines are exactly what they do not want in the park.. *shrugs* (noise, gasoline, exhaust fumes...)

I would argue that combustion engines are worse, for those reasons, but that they also do not want electric motors. I think one could make the argument that any motor driven vehicle poses a fire danger. eg. how do they know that my setup is properly built, and therefore will not overheat, or burn out its wires, or spark?

Sounds like its time for me to figure out who I can write a letter to. And maybe buy a welder.

 

[mckutzy]

When I first came across this topic, my first idea was to make something like this, an electric tug for your boat/rv ect trailer. Could be articulated to steer easier... but something like this could be easy enough.... Dc of course... unless you are within a few 100yd of a power source.

 

[itsid]

Well, again:
you do not want this motor for your own amusement,
you want it to clean up the garbage from the park.. which frankly should be in the interest of who ever is in charge.

IMHO they should pay you for doing so (which is unlikely to happen really) but in the end they should at least provide you with a permission to do so and to use all equipment necessary tohaul more quicker safer and easier.

Sure a leaking battery is not fun, how about marine grade batteries?
On the other hand.. what's your "in use battery" compared to the dozens of already leaking
batteries you can remove from the park with it?

I really do hope they see the benefit and help you the best they can.
but you have to let them know!
(send a letter and add some pics of what you're incapable of hauling "unpowered" to make the chairsitters aware of the issue at hand )

'sid

 

[Whitetrashrocker]

We use something like mckutzy posted but with a gas engine to move airplanes around. I thought some thing of the sorts too.

If they will let you clean trash out why couldn't you just use a quad with a trailer. They give permission to hunters to haul out their kill. Why not let you haul out the garbage.

Mad props to you for taking this on. I'm constantly picking up trash on our crawler trails. Makes me so mad that poeple have no respect for anything.

 

[Bbqjoe]

I see garbage along our dirt roads now and then.
Woe be to he what I see tossing it.

 

[Rail rider]

If a ranger cites you for a M.V while picking up trash ... He is a special type of stupid...

 

[Callipygous]

I still haven't managed to actually meet up with the ranger, but in phone conversations the best I got out of him is that he would be "more willing to look the other way on a motorized vehicle" than on the stuff I want to winch out of the creek. He's decided that winching is a high-tension, dangerous activity. More relevant in my mind is that hauling things out that are big enough to require a winch probably means tearing up hillside and causing erosion issues, so he wants to supervise any winching that takes place. oh well.

Point being, I have decided to at least carry on with building my cart. I know it won't really be good for anything except the activity I don't really have permission to do, but the idea of building it excites me. I'll probably end up using it to haul tires when the park is empty or something.

So, to that end, I have purchased a welder. (yay, I get to learn new skills!) I am looking for 55 gallon steel drums on craigslist. I plan to cut one in half, as that seems like about the optimum shape for hauling a stack of tires. And I am now looking into the details of powering the thing.

Though I like the idea of the wheelchair motor you posted, I cant seem to find any details on it, ie. what power supply and controller would it need, you said something about an internal brake, etc. I am feeling more inclined to just use an electric motor and jackshaft to gear it down a lot. If you are willing to help me figure out the wheel chair motor I could be talked into it. Otherwise, I have been looking for electric motors online. Does anyone have a recommended source for such things? I don't know why no online shopping sites have figured out how to provide appropriate sorting options...

 

[itsid]

As I said.. 75Amp (1800W electrical) peak
a good controller for that should be this:
http://kellycontroller.com/kds36100e100a24v-36v-mini-brushed-controller-p-270.html

powersupply: std 12V batteries in series to double the voltage
(gel type boat batteries are a bit expensive, but since they practically never leak much to your ranger's liking )

Frankly I don't understand the problem you're facing, you're scared about buying that thing and not being able to power it correctly I assume..
well I cannot help you with that I'm afraid.
To me it's an electric motor, juicy pixies in on end dancing oomphs out the other... Magic
Details will need to be figured out as they get in the way.

No, I cannot provide you with the perfect bulletproof guide on how to make use of that transaxle at the moment,
I know too little about it (brushed ... likely ... PM.. also very likely ... am I sure.. not too much)
does it matter if it's one or the other?
not really.. just buy a matching controller as needed instead of the brushed one I linked above.

And in case you wonder, yes you can also use a 24V eBike batpack instead (some array of LiPo cells); the controller doesn't care much; the motor couldn't care less

'sid

 

[Callipygous]

Thanks for the quick reply.

Frankly I don't understand the problem you're facing, you're scared about buying that thing and not being able to power it correctly I assume..
well I cannot help you with that I'm afraid.
To me it's an electric motor, juicy pixies in on end dancing oomphs out the other... Magic
Details will need to be figured out as they get in the way.

The problem I'm facing is lack of experience and confidence. Your description made it sound potentially more complicated, in ways that I am not familiar with. If you tell me electric motor, with an extra axle in between to gear it down... I understand how all that works and why I'm doing it. With this wheelchair one, I guess it's as you say:

No, I cannot provide you with the perfect bulletproof guide on how to make use of that transaxle at the moment,
I know too little about it (brushed ... likely ... PM.. also very likely ... am I sure.. not too much)

I have a rough idea what brushed means, but not why it impacts which controller I need. I don't have any idea what PM means or how big of a problem it would be. If it requires a different controller, I don't know how it needs to be different, or how easy to acquire the necessary controller would be.
Not that I don't believe you, but I'm having a hard time figuring out how you came up with 75amps. I cant seem to find any details on the thing except for "24v".

I suppose to sum up, my plan had been to find an appropriate motor, controller, and battery set up, run it by you guys to make sure it all checks out, and then buy it all at once. That way I have reason to believe its going to work, without unexpected changes in purchase plan, and total price.

That being said, you don't seem overly concerned about the potential hurdles, so I guess they typically aren't too hard to overcome.

Am I correct in saying the controller you linked doesn't seem to do regenerative braking?

Thanks again for your help.