HELP NEEDED - E-WINCH for SPORTS

Get all your technical information about electric bikes here.
Post Reply
SphericalNoob   1 µW

1 µW
Posts: 3
Joined: Jun 13 2021 9:34am

HELP NEEDED - E-WINCH for SPORTS

Post by SphericalNoob » Jun 13 2021 9:59am

Hi everyone,

I'm new here so apologies if I'm doing this wrong!
Your thoughts and opinions on any aspect would be greatly appreciated.

I'm looking to build an electric winch for sports such as wakeboarding, skiing, snowboarding etc.

The motor doesn't need to be very fast but I would like to be able to vary its top / constant speed from say 20kph to 60kph.
The motor will however will need to be strong enough to pull a rider out of deepish water as it will predominantly be used for wakeboarding.

I would like to use the hub motor as the cable drum so I was thinking a scooter or moped style hub motor that has a wider rim would be easier to modify.
I would like a way of soft starting to build up tension in the cable, a short burst of high torque to pull out of the water then back of slightly to coast along.

Also, as the cable/rope is pulled inwards the diameter of the drum will increase slightly also increasing the speed. Is there a way to counteract this effect so the winch pulls at a steady programmable speed.

Thanks in advance and sorry if I have missed anything out.

Fred

User avatar
E-HP   100 MW

100 MW
Posts: 2514
Joined: Nov 01 2018 9:20pm

Re: HELP NEEDED - E-WINCH for SPORTS

Post by E-HP » Jun 13 2021 11:24am

SphericalNoob wrote:
Jun 13 2021 9:59am

The motor doesn't need to be very fast but I would like to be able to vary its top / constant speed from say 20kph to 60kph.
The motor will however will need to be strong enough to pull a rider out of deepish water as it will predominantly be used for wakeboarding.
I would use the Grin simulator to get an idea about whether your idea is feasible or not.

is this your desired towing speed? If so, you need an very fast wind motor and high voltage. Here's a MXUS 4503, which is fairly wide, with a fast wind. Assuming your cable wrapping around the motor/pulley is 9" diameter, you'll barely hit 60kph, and this is without simulating your load (simulator assumes flat ground and no wind, but includes wind resistance in the rider position (for ebikes) parameter. For your water resistance, you may be able change the grade parameter to simulate increased load, as well as the vehicle weight, which both impact the assumed load.

https://ebikes.ca/tools/simulator.html? ... i&mass=100

You would need to estimate the water resistance, which would seem to be pretty high initially when pulling the person when they are initially submerged. Once you calculate that, you could use the simulator to change the vehicle weight and assumed grade, to increase the load used to match your estimate. However, the grade parameter maxes at 20%, so depends on how much load towing someone out of the water from a stop takes.

https://ebikes.ca/tools/simulator.html? ... mass_b=170

User avatar
dogman dan   100 GW

100 GW
Posts: 36030
Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: HELP NEEDED - E-WINCH for SPORTS

Post by dogman dan » Jun 16 2021 5:50am

Big engine starter motor maybe?

Post Reply