RC Boat - Pump Jet Boat (Large) / 遥控船-喷射泵 (大)

thingiverse

4/3 Scale version of https://www.thingiverse.com/thing:4606971 4/3 MOAR betterer 600 mm total length - able to accommodate 36XX series motors 42 mm mixed flow first stage 32 mm axial flow second stage should fit 300 x 300 CR10 class printers Refer to original project post processing pictures for detailed build instructions as well as updated BOM below. For screw lengths most screws increase in length by 4/3 and dia from 3mm to 4mm unless otherwise specified. BOM: - 36XX motor (max cooling jacket dimensions are 45 mm Dia and 65 mm long) you can also design your own mount using the custom motor plate template step file (pending). Keep weight and cooling considerations in mind if using an alternate - ESC: Water proof ESC appropriately rated for your motor / battery combo - Cooling Nipple: M4 X L15 https://www.aliexpress.com/item/32614416689.html - Cooling Tube: 4 mm I.D 7 mm O.D https://www.aliexpress.com/item/32619454548.html - Stuffing Tube: 9.5 mm O.D, 4 mm I.D Length L8 cm https://www.aliexpress.com/item/32985647360.html - Cardan Joint: If 36XX Motor with 3.175 shaft you will need a 4mm to 3.18 mm cardan joint - Prop Shaft: https://www.aliexpress.com/item/32917025303.html 20 cm long 4mm dia shaft (some modification needed; you will need to cut down to 184 mm with a dremel or hacksaw and file two new flat spots for engaging the set screws) - Servo: 9g servo (important you will want to waterproof or find an alternate waterproof servo) if anyone knows a reliable and waterproof 9g model please post in comments - Reinforcement: 6 mm OD 4 mm ID Carbon Fiber Rods. Note: carbon fiber tube cutoff lengths change to 265 mm (qty 4), 105 mm (qty 2), and 145 mm (qty 2). https://www.aliexpress.com/item/32310771446.html - Power Source (btw if, like me, you are inexperienced with RC make sure to inform yourself about some of the precautions needed with lithium based batteries especially around charging and storage. Unlike your consumer electronics the LiPo cell is very much exposed in RC and special care must be taken. RC Review and FliteTest do some good youtube vids on the matter) : The maximum extents of a battery able fit in the front of the boat are 110 X 48 X 35 mm - Receiver and transmitter: Up to you (and your local regulations), I'm using a Flysky FS-i6X transmitter and FS-GR3E Waterproof receiver (note i6X will need to be in AFHDS mode to work with FS-GR3E) - 604 Bearings - M4 X D7 X L8 Embedded Nuts https://www.aliexpress.com/item/4000232925592.html - M4 Machine Screws (Flat head) https://www.aliexpress.com/item/32934186482.html - 5 mm Dia X 5 mm long neodymium magnets - XT60 connectors, 3.5 mm bullet connectors, grease (marine), filament material compatible glue. The connectors are sold by the same storefront as much of the material above. Print Settings: Note the walls themselves have been engineered with reinforcement - deviation from recommended print may result in sub-optimal results. Cura has a setting under Travel called combing mode which helps reduce stringing in the inaccessible interior. Personally I'm printing in PETG but ABS or ASA might be a good options too if you are setup for that with enclosure and ventilated space (due to easier gluing / reduced density - if using ABS or ASA I would advise against acetone smoothing as thin walls will likely deform). I excluded PLA as it is not as temperature / weather / UV resistant as the above materials and will swell / deteriorate in water unless waterproofed. I print at between 30 mm/s (TPU) and 50 mm/s (PETG) but it might still print well at higher default speeds. Thrust vector nozzle, and stator bowl will be printed in TPU for its reliable layer adhesion as these components will have servo wire inserted and removed repeatedly if adjusting ride plate or throw arm connection. STL files are already saved in as print orientation. *Note I've noticed that upon updating Cura that support generation varies between versions so you may need to tweak support overhang angles from posted values below - make sure to do a preview to check for proper support and alter as needed - values below updated for Cura 4.10.0 PETG/ABS/ASA Parts - Boaty (PETG/ABS/ASA): 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 1 walls, 5 bottom layers, 5 top layers, 16% grid infill, supports on overhangs over 70% touching buildplate - McBoatface (PETG/ABS/ASA): 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 1 walls, 5 bottom layers, 5 top layers, 16 % grid infill, supports on overhangs over 78% touching buildplate, brims are helpful for ensuring support adhesion - Cover: (PETG/ABS/ASA) 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 1 walls, 3 bottom layers, 3 top layers, 16% grid infill, supports on overhangs over 60% touching buildplate - Motor Mount (PETG/ABS/ASA): 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 5 walls, 3 bottom layers, 3 top layers, 25% grid infill, supports on overhangs over 70% touching buildplate , brims are helpful for preventing warping - Ride Plate: (PETG/ABS/ASA) 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 5 walls, 3 bottom layers, 3 top layers, 25% grid infill, supports on overhangs over 70% touching buildplate - Servo Hatch: (PETG/ABS/ASA) 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 4 walls, 100% infill, supports on overhangs over 70% touching buildplate, brim - Stage 1 / 2 Impeller / Mid Stator / (Cooling Impeller): (PETG/(NYLON might be a good option too)) 0.4 mm or 0.6 mm nozzle, 0.06mm layer height, 3 walls, 100% infill, supports on overhangs over 50% touching buildplate, brim. Note caution is warranted with the cooling impellers - the layer adhesion issues inherit to 3d prints makes it possible for the impellers to fracture under load. Wear eye protection and be mindful of risk when using TPU parts - Thrust Vector Nozzle (Open): (TPU) 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 3 walls, 3 bottom layers, 3 top layers, 25% cubic subdivision infill, supports on overhangs over 70% touching buildplate - Stator Bowl (Axial): (TPU *note the part can also be printed in PETG/ABS/ASA with the same settings - the part seals the gasket better in the harder plastics but the servo wire for the adjustable ride plate will need to be thinner 1.2 mm) 0.4 mm or 0.6 mm nozzle, 0.16mm layer height, 3 walls, 3 bottom layers, 3 top layers, 25% cubic subdivision infill, supports on overhangs over 70% touching buildplate - Stator Bowl Gasket: (TPU) Solid