I have developed a design for a river cleaning machine which can cut and collect weeds. The problem which is facing is how to rotate the circular blade which is attached in front of the machine. I mean first is to directly attach on a dc motor's shaft but there are less to zero options available for waterproof dc motor. Next is to shift the motor to another place and add a chain connection between the motor and the blade.

I am not a mechanical engineer. Can anyone help to figure out what should be the best way to solve this as I have to use nonwaterproof motors.enter image description here

The black circular spiky thing is the blade which is attached in front of the body.

  • $\begingroup$ use hydraulic motors as the most likely vehicle working close to a river is an agricultural tractor or equivalent which will have an hydraulic system... $\endgroup$
    – Solar Mike
    Nov 6, 2019 at 15:48
  • $\begingroup$ Belt drives are probably better than chains in this context although I agree that hydraulic motors might be better than electric motors. $\endgroup$
    – Eric S
    Nov 6, 2019 at 18:56
  • $\begingroup$ @EricShain do you think the belts might pick up weeds and get blocked? $\endgroup$
    – Solar Mike
    Nov 7, 2019 at 12:19
  • $\begingroup$ V-belts aren’t much wider than chains and don’t rust. As for function, I’m not even sure what those spike wheels are doing. $\endgroup$
    – Eric S
    Nov 7, 2019 at 15:19
  • $\begingroup$ @EricShain the OP says cut and collect weeds... $\endgroup$
    – Solar Mike
    Nov 7, 2019 at 15:37

1 Answer 1


Small, waterproof electric motors are commonly available as electric outboard motors that run silently on 12VDC and are used by sport fishermen and also to power small sailboats into and out of harbors. You'd convert them to saw use by removing the propeller and replacing it with a circular saw blade which has been modified to fit onto the propeller shaft, or by making a metal adaptor which allows the blade as-is to be mounted onto the shaft. This is the better option, since saw blade material is hard to machine.


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