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eGull outboard motor

Creation's quality: 5.0/5 (2 votes)
Evaluation of members on the printability, utility, level of detail, etc.

3D model description

Welcome to the eGull outboard motor project.
Mostly 3D printed, full size and fully functional Short Shaft outboard motor equivalent to typical 2hp petrol engines but without the weight, mess, fuss, noise and emission's.
This post is for the Leg 5 upper leg section only. The main files and documents can be found for free at:

There are alternative versions of this engine:
Steel shaft version - Cuts down on the printing and adds a bit of strength but is slightly heavier.
Better cooled version – Gives longer running times and higher loads.
cults/eGull cooled

Check out the videos on my youtube channel which include the engine in use and some simple build videos. YouTube Videos

The eGull comfortably drives the small craft and dinghies typically found as tenders or small leisure boats.
Ultralight, quiet and convenient, quick change “off the shelf” batteries, zero emission and an absolute joy.

With one battery and ready to go it weighs 4.7kg!! Average for a 2hp Petrol engine fuelled up is around 19kg.
Our own Mercury 3.5hp which has been replaced by a Long Shaft version of this engine weighs 20.7kg. I weighed it when I lined it up for the picture with the Short Shaft and Long Shaft engine next to the Mercury 3.5.

It uses easily available standard lipo batteries or cassette style batteries from a range of electric garden tools. One 4ah battery gives about 20 minutes running at typical tender cruising speeds. The engine has holders for the working battery and a spare but carrying loose spares is no problem. I pack my spare batteries in my Wife's picnic bag when she is not looking!!

Largely 3D printed with some hardware and off the shelf electrics needed to complete the engine. Prices in February 2020 (UK) gave a total cost of under £200 including two reels of PLA and one battery.
The printed parts can be made using PLA and it will work fine with some care in handling etc. Parts such as the prop blades, skeg and pulleys could be made of nylon or similar for a more durable engine. For the top drive pulley an off the shelf aluminium one could be used instead.

This engine is an absolute joy to transport and use. I have added a small selection of pictures and youtube has videos that should give a good impression of its capability. I think it looks pretty neat as well but I am probably biased!!

This project is very much a work in progress and I am hoping that funds from the small stl charges or donations will give enough development funds to continue the project.
Donations can be sent to mikejjeffs paypal
If you are able to support this project in any way it will be greatly appreciated.

Links to some of the parts used:
ESC - HobbyKing Red Brick 200A ESC V2 - About £28.00.
RedBrick ESC

Battery - As of 15/11/2021 they have £34
Turnigy 4ah Lipo

and £39
Zippy 4ah lipo

Servo Tester - Link to the hobby king one:
Servo Tester

On my todo list:-
I have a long haft steel version which is under trial to develop the best prop and this may push the output up to over 3hp and maybe over 4hp (equivalent petrol).
I would like to add a display screen with battery life and consumption.
Possibly link it to GPS so that distance left to travel verses distance left in batteries at current consumption can be displayed.
Even better cooling is being developed and a few other mods to improve endurance over longer distances.
Water cooled esc's are easy off the shelf for model boats etc and I may build enough space for a cheap (solar fountain type) water pump in the bottom. This could then feed the esc and also a water cooled motor plate.
I also have a retro styled version that may be offered. Styled similar to the legendary British Seagull.
I am considering offering printed and hardware parts kits but I would rather spend my time focused on development rather than getting stuck with printing parts and supply chains etc etc.
If I can obtain sufficient funds I think we could drive the cost right down by buying the parts in volume to supply a standard parts kit. That would also make everybody's life so much easier.

3D printing settings

Print settings and documents are available from

3D printer file information

  • 3D design format: STL and ZIP Folder details Close
    • eGull_printed___case_battery_box_v1.stl
    • eGull_printed___case_battery_holder_v1.stl
    • eGull_printed___case_esc_holder_v1.stl
    • eGull_printed___case_lid_bobbin_v1.stl
    • eGull_printed___case_lid_catch_v1.stl
    • eGull_printed___case_lid_v1.stl
    • eGull_printed___case_nose_box_v1.stl
    • eGull_printed___case_nose_cap_v1.stl
    • eGull_printed___drive_pulley_v1.stl
    • eGull_printed___leg_1_v1.stl
    • eGull_printed___leg_2_and_leg_3_v1.stl
    • eGull_printed___leg_4_cav_plate_supports_v1.stl
    • eGull_printed___leg_4a_v1.stl
    • eGull_printed___leg_4b_v1.stl
    • eGull_printed___leg_5_lower_v1.stl
    • eGull_printed___leg_5_skeg_v1.stl
    • eGull_printed___leg_5_upper_v1.stl
    • eGull_printed___motor_bracket_v1.stl
    • eGull_printed___motor_plate_v1.stl
    • eGull_printed___prop_blade_v1.stl
    • eGull_printed___prop_hub_end_cap_v1.stl
    • eGull_printed___prop_hub_spacer_v1.stl
    • eGull_printed___prop_hub_v1.stl
    • eGull_printed___prop_pulley_v1.stl
    • eGull_printed___steering_handle_bracket_v1.stl
    • eGull_printed___steering_handle_shaft_v1.stl
    • eGull_printed___support_plate_v1.stl
    • eGull_printed___tensioner_bearing_spacer_v1.stl
    • eGull_printed___tensioner_body_v1.stl
    • eGull_printed___tensioner_screw_body_v1.stl
    • eGull_printed___tensioner_screw_button_v1.stl
    • eGull_printed___transom_angle_adjust_knob_v1.stl
    • eGull_printed___transom_carry_handle_v1.stl
    • eGull_printed___transom_fixed_connector_v1.stl
    • eGull_printed___transom_fixed_port_v1.stl
    • eGull_printed___transom_fixed_stbd_v1.stl
    • eGull_printed___transom_friction_insert_v1.stl
    • eGull_printed___transom_friction_knob_v1.stl
    • eGull_printed___transom_half_clamp_bottom_v1.stl
    • eGull_printed___transom_half_clamp_top_v1.stl
    • eGull_printed___transom_hinged_v1.stl
    • eGull_printed___transom_lift_and_bump_stop_knob_v1.stl
    • eGull_printed___transom_lift_stop_catch_v1.stl
    • eGull_printed___transom_mounting_clamp_v1.stl

    Learn more about the formats

  • Last update: 2021/12/02 at 20:11
  • Publication date: 2021/11/20 at 11:27





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