- Location
- Spring Lake, MI
In the sense that it's awd and dual motor. At the end of a typical day on lake michigan, there would be three to six skis that would need to get pulled and pushed back up to the parking lot across the beach. the 4 wheeled ones worked best but still takes two or three people to get it up the incline. I fabricated my own two wheeled cart to break down and fit in my car. I was able to use that this season, but became jealous of some of the motorized models that sell for big bucks.
Motors are 24 volt 350 watt with a 9.78:1 gear ratio. They come with a 9 tooth bike chain(410) sprocket. The larger sprockets is a 48 tooth that is modified to work with the go cart axle sprocket and disk brake hub. The disk brake hub has a slightly larger center boss with different bolt pattern, although it shares the same internal spline as the sprocket hub. With the 18" tires, that gets me to 3.5mph. I slotted the motor mounting holes 1" for chain adjustment. Added an extension to the c-channel to get the proper footprint. I did some initial testing with one and I feel it would be just enough. With two I was able to tow a second ski on a beach cart loaded with gear and gas.
The go cart axle started out as a 29" kit that comes with a sprocket hub, brake disk hub, wheel hubs, and pillow blocks. To make it work with my existing cart, the axle needed to be cut and extended. The pillow blocks were modified to fit inside the c-channel.
There is only one 7" wheel option for the three hole wheel hubs that come with the 29" axle. That limits the tire sizes to around 16". I took the existing 8" wheels and modified them to accept a welded on 3/4" spacer that has the integrated concentric center and threaded mounting holes.
The batteries are 12 volt 10ah sla from amazon. Fully charged, the voltage is 26.5 volts. After pulling three skis, it dropped to 25.8 volts. It's recommended to not go below 50% capacity on sla batteries, so that would put the low voltage cutoff at 23 volts. Theoretically I can pull 15 skis before reaching that limit. I 3d printed the battery bases and used bungie cord to keep them strapped in. The controllers are 350/500 watt and uses a thumb throttle for smooth operation. I initially used a push button kill switch to trigger 40amp relays. It worked, but having the throttle an on/off switch made for difficult control taking off. It would probably be better on a four wheeled cart. On a two wheel one, it acts like a lever and either pulls down up on the bars quite violently.
Overall I'm pleased with the first gen model. Likely changes for next year will be lower slung batteries to they don't get so close to the underside of the hull. I need to make some t-handled axle nuts to make the wheels removable. I'm quite happy with everything else. Total cost for the conversion is about $400. Typical routine is to use a 4 wheeled cart to get the ski from the water to the edge of the beach, then slide it onto the motorized cart to take up. The downside is this can't be submerged in water, and the equipment to be able to do that would be cost prohibitive. It's current configuration is able to do 95% of the travel, and a single person can now take their ski up without help. The first video is with a single motor and relays for control. You'll also notice I'm "pulling" the cart compared to "pushing" in the second video. I realized quickly that "pushing" it is much better because I can have both hands on the grips and the torque of the wheels makes the handlebars get pushed down, not up. The second video is in the current configuration with dual motors and thumb control. I'd like to hook up an amp meter and get an idea on the actual draw for better estimation of battery life.
Motors are 24 volt 350 watt with a 9.78:1 gear ratio. They come with a 9 tooth bike chain(410) sprocket. The larger sprockets is a 48 tooth that is modified to work with the go cart axle sprocket and disk brake hub. The disk brake hub has a slightly larger center boss with different bolt pattern, although it shares the same internal spline as the sprocket hub. With the 18" tires, that gets me to 3.5mph. I slotted the motor mounting holes 1" for chain adjustment. Added an extension to the c-channel to get the proper footprint. I did some initial testing with one and I feel it would be just enough. With two I was able to tow a second ski on a beach cart loaded with gear and gas.
The go cart axle started out as a 29" kit that comes with a sprocket hub, brake disk hub, wheel hubs, and pillow blocks. To make it work with my existing cart, the axle needed to be cut and extended. The pillow blocks were modified to fit inside the c-channel.
There is only one 7" wheel option for the three hole wheel hubs that come with the 29" axle. That limits the tire sizes to around 16". I took the existing 8" wheels and modified them to accept a welded on 3/4" spacer that has the integrated concentric center and threaded mounting holes.
The batteries are 12 volt 10ah sla from amazon. Fully charged, the voltage is 26.5 volts. After pulling three skis, it dropped to 25.8 volts. It's recommended to not go below 50% capacity on sla batteries, so that would put the low voltage cutoff at 23 volts. Theoretically I can pull 15 skis before reaching that limit. I 3d printed the battery bases and used bungie cord to keep them strapped in. The controllers are 350/500 watt and uses a thumb throttle for smooth operation. I initially used a push button kill switch to trigger 40amp relays. It worked, but having the throttle an on/off switch made for difficult control taking off. It would probably be better on a four wheeled cart. On a two wheel one, it acts like a lever and either pulls down up on the bars quite violently.
Overall I'm pleased with the first gen model. Likely changes for next year will be lower slung batteries to they don't get so close to the underside of the hull. I need to make some t-handled axle nuts to make the wheels removable. I'm quite happy with everything else. Total cost for the conversion is about $400. Typical routine is to use a 4 wheeled cart to get the ski from the water to the edge of the beach, then slide it onto the motorized cart to take up. The downside is this can't be submerged in water, and the equipment to be able to do that would be cost prohibitive. It's current configuration is able to do 95% of the travel, and a single person can now take their ski up without help. The first video is with a single motor and relays for control. You'll also notice I'm "pulling" the cart compared to "pushing" in the second video. I realized quickly that "pushing" it is much better because I can have both hands on the grips and the torque of the wheels makes the handlebars get pushed down, not up. The second video is in the current configuration with dual motors and thumb control. I'd like to hook up an amp meter and get an idea on the actual draw for better estimation of battery life.
