100mm kayak drive system

thingiverse

the original prop i started with can be found here.i do thank the OP for the base design. https://www.thingiverse.com/thing:226735 work in progress,will add more . 100mm (4") prop for a drive system im working on to replace the 55mm jet drive in my kayak.im experimenting with low rpm high pitch props.(motor mount not needed for standard kayaks,it was needed for me to cover up the jetpump intake hole) im using a $25 100-150w 68mm scooter motor driving this 100mm med-blade prop. sofar pool test at 12v 1800 rpm the prop wash exceeds my 12lb thrust trolling motor,and the 100w motor runs cool.so i can probably increase the diameter just a lil more. havent tried on 24v yet. i wanted to keep the prop under 5.5 inches. this prop utilizes the common 4mm drive dog system for rc boats,4mm shaft. ebay sells this setup for under $15 shipped in various lengths.(pack with marine greese befor use) im eliminating the jet drive pictured,i just added the pics so you can see what im working with. for the intrested in the jet drive,i had a very hard time finding an efficient motor with enough power and rpm to be happy with it.i settled for a dewault 18v motor driving a 2.5:1 gear reduction and it still ran too hot after 15 mins at 3.5 mph wot.and it was very loud. i only was able to get the 55mm impeller to about 4k rpm.jet pumps need high rpms to really perform. its advantage was nearly zero drag.if i had to paddle,the jet drive didnt slow me down. a prop on the other hand will. but under power a prop is more efficient. all this is just experimenting for me.i have a bad shoulder and cant paddle very far without alot of pain and discomfort,but i love going on kayak adventures in my local waterways. i want to achieve this without the bulky,heavy trolling motor options.im also avoiding the $1000 kayak motor alternatives. i print with support in the center hub of props,no support on the blades. at a later date ill find my ruder system stl files and add them here,for the rudder blade i used a cheap teflon cutting board and a 19mm composite hollow shaft from home depot. sofar ive only ran on 12v,motor and my controller can handle 24v. controller im using(forward only for my aplication,it can be bought for $15 with reverse) https://www.ebay.com/itm/12V-24V-48V-2000W-10-50V-40A-DC-Brush-Motor-Speed-Control-PWM-HHO-RC-Controller/111851538617?hash=item1a0adf08b9:g:za4AAOSw-q5bbTws:sc:USPSFirstClass!70363!US!-1 the shaft im using (im going to redesign to use the 300mm version) https://www.ebay.com/itm/4mm-200m-RC-Boat-Shaft-Drive-Dog-150mm-Stainless-Steel-Tube-w-Left-Propeller-Set/382905832082?_trkparms=ispr%3D1&hash=item5926f75292:g:9VAAAOSwG8ZctqIO&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYYiKC1w5811lg4WR49T8eC1w3l3gEZUTJJgtdKHbYMbm4GHfAejzwXJlEvSSy25udy%2FMmUKt%2F2JXNskE7MI8%2Bqw3zAry5VC0MDHzN85%2BmSHSNwbaMirrEXi%2BijOpGfxrxHIJvlH2Bgb%2FBR%2Bol%2FeFOCSQ0Am0mo5%2BjTTedeOT%2Bgfclzi2z8Ca6%2BQqb57BbtARSJkBSfFvhdkYfZ5bcukI2IS8JpZamvhSn17ApP1QLXtv3QU5BVdx2WPaXU8GcppMFksxTCrIS%2BV7C2xbPz4RQ23wqqiMHIviS0ZQVUWLfwuBHzoNahK6NtE1%2FlWcNx0dyQxz3Sohqwk%2FhaJXXT47OamIerIFqDn9pvfdz3yLSMzaJ%2BSMFvni65mPy1k3FUtONizPoU0XYdB4cGlrlA8gJIDxt1aJNslvHhLr5z0uo57UHrsh9egz%2FiD%2F3LjWbZpJ6ttvyis8vE%2B2rr6GVBCgf8qybHvijxm0LLkqEBLXR%2FfTyfLIzPww%2BHjvwBJb3jhOKzhdsIB4fPpSM3pDC0g0fSSktpTZ4ufBgVoHuqB97ENBbEuyk9y6dL4D4WB1W2dFjnjwdc%2FaHeNyXduXdQBq5vMfVWdvoMlmWsKmqW9c8vmBA%3D%3D&checksum=3829058320829aa6f76da1e9435db2b3c4fb668d8fa1 the motor 12v 8mm shaft 2700 rpm https://www.ebay.com/itm/100-W-24-V-12-V-DC-electric-motor-25-chain-sprocket-ZY6812-f-scooter-kids-kart/152421672085?_trkparms=ispr%3D1&hash=item237d0a2495:g:IW0AAOSwT2daLAuv:sc:USPSPriorityMailPaddedFlatRateEnvelope!70363!US!-1&enc=AQADAAAB4KX%2FKt4E1xf3SDqEdBclaYYGvvUD%2FcLV8sNeA9leBV%2FxZJvQUT%2FZZ%2BZVhmTN3ra%2FrLNO9ZNHjX2AFDqwH%2BQLVjOqLw5%2FXx9Lr0KD061qVELaBbQeMHIvIwpiJOgSVQ6tO55HRm9TNXgIIJ4HC6OuAHx1SF%2FTXZ7qrOSvxq3yoABbTZCI3i6aQr%2BNWk%2FcKu066GypUeM%2FeIOgpESeq%2FwZUyNkV0VtW56QoBZuU8bqPkFaC60ivbwBV9DnGcmDyU2xC23iNX2hQS%2BKWH1ikK3ZNYD%2FjDdsn0AUGV8M39ymbxvmPbEkAKdDFtlq2M%2BpE5W0GS3BCOE56FayRstuNociXcSMGnJQSOvVS7wWhnTeZFJJefM5GZMfab5pxSk7tz7HYxBTbVYaO3GjEUvCHM6p9lZifjGXGGMpTokolgxpqTo0l%2BzFu7%2FhESF67bvhLC61c5dq3W4tiFyGxe23pLwHCAdJSfJ%2Fpibul8e9Dycv93ebJEtl7OzpbNwhjUWTzItFwo0bGqMrBRYBoOLzwCfuPGYeJExj%2BTxVE7EnFvOmJys1yI8af4FOb8akkRqbXluiG6RPncEKDWouDrYQjcjQGqyHMglKU1H%2BixYXAFBTffL9P0dRCQrUniW1EJ9saq9GYQ%3D%3D&checksum=15242167208570f0c6de846c423fbec89311c01de723 and the coupling https://www.ebay.com/itm/4-mm-x-8-mm-Aluminum-Flexible-Shaft-Ballscrew-Coupler-Coupling-CNC-Linear-Motion/171112721294?hash=item27d71ceb8e:g:n-MAAOxyaoFSGTs4 later on ill post up the housing and motor mounts once i fine tune it to fit my kayak. im using a lifetime tamarack/tahoma/tioga.....lifetime uses this same hull for 5 different models.the tahoma is the cheapest option at $170-200 average price. i already have holes cut in my hull for the jet drive,so im building the new mount and sterntube to utilize and cover the existing holes i already have.