Slow Hill Climber

[etahoe]

Im making an electric beach cart that needs to climb hills approx. 30% sloped at about 3-5 mph.

I have two options one is 16 inch wheels with a geared hub motor or a motor with chain and gearing.

I was just wondering if there was a hub motor capable of doing those requirements without getting destroyed?

Thanks for any help

 

[Rassy]

You might find a hub motor that can climb a 30% grade in a 16" wheel, on a paved road. But in sand I would expect severe problems. I recently put a slow speed Bafang geared hub motor on a Bob trailer for a friend. It's doing okay on 15 to 20% grade, but it does work pretty hard. It runs at about 14 MPH on the flat at WOT, so once you get down under 5 MPH the motor would be lugging down a lot and creating a lot of heat under power.

If you run a mid/crank drive through the gears you can select your gearing so that the motor is running in it's happy zone. If you don't get it right on your first try you may just have to change one cog or chain wheel to correct it.

Just my 2 cents, but I never was real happy with any of my hub motor experiments, even with multiple motors, and my hill tops out at only 20% grade, all pavement.

Edit: These are all running at 48V.

 

[wesnewell]

You can get hub motors as small as 6" from GM.
http://www.goldenmotor.com/

 

[el_walto]

I'd try a MAC 12T 16" wheel with 24V. Get a 24v controller with high amp rating? Might be hard to find, as most seem to require 36V.

How long does it have to run up a super steep hill?''

how heavy will the cart be?

ok, ok maybe i'm crazy.

 

[dogman dan]

Something non hub should work better, but then again, chains and sand? Maybe you could drive it with a toothed timing belt or something.

The Golden motor wheelbarrow motor should be the best hubmotor option. Particularly since the number one thing you must have is a fat tire. No bike wheel is going to cut it in a foot of sugar. That sand can smoke a hubmotor on flat ground. So you must build to float on top of it.

Hmm looking at that motor, you might still need to do something to make it wider. Screw some old tire tread to it maybe?

 

[etahoe]

Thanks for all the help.
Its not going to be used on sand its just used to get back and forth from the beach on dirt trails. Its going to be around 100 lbs of weight to hold.

Its basically all uphill and then all downhill on the way back. At least 30 min uphill could be more depending on which route I take.

 

[el_walto]

Sounds interesting. You'll have to post some more details and pictures of your plan.

 

[etahoe]

Thanks I hope it will be interesting. I will post up designs, Im just trying to finalize if I can use a hub motor or a motor with gears.

 

[dogman dan]

I would think then, those 6" hubmotors would work. Put one on a wheelbarrow.

 

[MadRhino]

30 minutes climbing is long, or very slow.
Either would call for a mid drive,
on a fatbike frame if you ask me.