I am an engineering student and my capstone project is to design and build and electric cart to transport two welding cylinders. We have the cart designed and now we are trying to determine a motor size. Calling manufacturers hasn't gotten me anywhere.
~ 600 pounds
walking speed (~3 mph)
15 degree max incline
Can anyone provide guidance ?
We can help and have practically all of the parts that will be needed. Figuring out the gear ratio for a 3 mph top speed is the first step. We can figure out the correct gear ratio and sprocket sizes using our gear ratio calculator. Do you know what size tires (outside diameter) the dolly has or will have?
Yes. The front two wheels on the drive axle are 13 inch diameter
13" Drive wheels
3 MPH max speed
15 degree max incline
600 pounds max total weight
Any help with spec'ing out parts will be greatly appreciated!!
We need a better option for batteries, a throttle, controller, motor and brakes
A 24 Volt 350 Watt motor pulling 600 pounds up a 15 degree incline at 3 mph is very close to the motor's power limit. I think it would work however it does not leave much room for occasionally pulling up steeper inclines. If you want to overbuild the machine, a 36 Volt 600 Watt motor would be a better choice, however the cost of electrical parts would be more if using a 36 Volt 600 Watt gear motor and electronics compared to using a 24 Volt 350 Watt system.
And here is an example of a 36 Volt 600 watt gear motor kit that sells for $635.00:
We can modify these kits with different parts such as larger or smaller batteries, different size sprockets, different style throttles, etc. For example if the kit with 36 Volt 600 Watt motor was modified to have smaller 22Ah batteries and a smaller 2.5 Amp battery charger then its cost would be decreased by around $200.00.
Please let us know if you have any questions.
With your experience, do you foresee any issues with our cart having two motors which are powered independently or would you suggest us having both motors on the same controller
Having two motors powered independently with two controllers would not cause any issues at all, and one throttle could be connected to two controllers so they are both regulated with a single throttle. Using one controller for two motors would also work without any issues. Either way would work great.
This is very helpful and we really appreciate it. We will most likely be ordering a kit from you for our project so we will probably make some changes to what it includes.
-Do you guys carry the #40 60 tooth sprockets and chains we would need?
-We only need this thing on and running for maybe 10 minutes at a time between charging... I have someone looking into what that actually means mathematically for batteries, but off the top of your head what would you recommend for two motors running for that long?
-We would still need the throttle, controller and a fuse but now we will need provisions for the duel motors and also we would like a circuit breaker instead of a regular fuse.. is that possible?
-Would you know off the top of your head what we would need for a "dead man switch" to wire in to our circuit?
-We have a mechanical brake system that is basically a bar held tight across the wheels by springs . The thought is that the bar will be actuated until the operator pulls a lever to disengage the bar.. adding a sort of "safety" feature if the operator should remove his hands from the handle bar the cart will stop. Would any of the brake lever kits here work for a system like that? I can provide a sketch if it does not make sense. We are still working through the design so theoretically we could make changes to accommodate for the kit available.
I will probably think of more components that we will need for our assembly but that is a start for our purchasing process.
Looking at the chart you will notice that a 12Ah battery pack can output 36 Amps for 7 minutes. Unless you are planning on driving the dolly up a steep hill for more than 7 minutes at a time then a battery pack made from three 12 Volt 12Ah batteries would do the job and would provide a 10 minute or longer run time.
We can switch the fuse in our kits over to a circuit breaker, that is no problem at all.
For a dead man switch one of our handlebar mount momentary switches such as SWT-25 could be used as the main power switch, or in conjunction with another main power switch. It can be viewed on this page:
We carry brake levers and cables that could be used to disengage the bar brake. They can be viewed on these pages:
We can start making a kit for your project once all of the parts that you want to have in it have been chosen. If you could let us know the part numbers of the parts for the kit we could go ahead and make it.
If you have any further questions or need any information about our parts before choosing which ones to include in the kit then please let us know, and we will be glad to help.
These are the items that we need for the kit:
36 Volt 600 Watt Electric Scooter Gear Motor (MOT-36600G) x 2
10 Feet of #420 Chain with Master Link (CHN-42010LF)
#420 Master Link (CHN-420ML)
BAT-12V12A, 12 Volt 12 Ah Battery Model WP12-12/T2 With 12 Month Warranty x 3
3 Pin Black Nylon XLR Charger Port with Cover and 12" Wires (CNX-XLR05W)
Full Length Wuxing Twist Throttle with 36 Volt Power Meter (THR-110)
36 Volt 800 Watt Speed Controller (SPD-36800B)
Handlebar Mount On/Off Power Switch (SWT-21)
36 Volt 2.5 Amp Automatic Battery Charger With 3-Pin XLR Plug (CHR-36V2.5AXLR)
we would also like a circuit breaker - whichever you feel is appropriate