75mm prop kayak drive

thingiverse

if your not affraid to make a 43mm holes in your hull,along with a few screw holes.....youve come to the right place.i chose the lifetime tamarack/tioga/tahoma,muskie angler.....all the same hull mold,just different accessories.the tahoma the base model and sells for $170 average at walmarts.they are 50lbs,track beautiful and plenty stable and all made from roto molded hdpe. designed a prop for max thrust on low rpm. ive used a ryobi cordless circular saw motor with 5:1 gear box.the output shaft spins 3000 rpm on 13v,so i needed a high pitch prop for the most thrust i can get from 3000 rpm. in the rc world....not many if any prop choices. this motor and prop setup matchs what my 18lb thrust trolling motor does on my kayak,3.5 mph for 2 hours from a 18ah battery.75mm was the most this motor wanted,its gets about 120f after 30 mins riding.....but doesnt get any hotter than that. on a static load temps reached 140f,but thats the most load a motor will ever see,less stress on a dynamic moving test. later on ill upload the housing i designed to install this into my kayak. the ryobi gearbox has a 10mm shaft,i used a 5mm rc boat shaft and sterntube with rc drive dog locking the prop on. stern tube od i used is 8mm. the smallest blade prop is perfectly matched for the 775 motor on a 5:1 gearbox that im using,and works well for my payload.full weight in the water with myself,fishing gear and battery is 260lbs total weight this motor has to move. its putting out from 15-18lbs of thrust,drawing 7 amps full load.im controlling the motor with a 40 amp pwm controller off off ebay for $10. my current battery is a $20 mower battery rated at 18ah,so ive got 2 solid hours before battery is low. the motor is rated for 18v,id imagine it would gain performance if ran at 18v. my motor mount plate had to be long to cover up the jet pump intake hole,ill make a shorter version for everyone else.......who shouldnt have a 55mm jet pump intake hole in their kayak.....lol.