3D printed Jet boat V2

Version 2 of the 3D printed jetboat project.

Maker/DIY

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Description

Version 3 is now out: The only changes are a new hull shape. All version 2 and 3 parts are compatible.
https://www.youmagine.com/designs/version-3-3d-printed-jetsprint-jet-boat

running on 12volts (3S)

Running on 24v (6S)

Too fast! I look forward to trying it out on a smooth lake one day.

Forum thread: https://www.rcgroups.com/forums/showthread.php?3061106
Version 1: https://www.youmagine.com/designs/prototype-jetsprint-jet-boat
Version 2: (you are here)
Version 3: https://www.youmagine.com/designs/version-3-3d-printed-jetsprint-jet-boat

Modeled in Solidworks 2016. Source files are included in the ZIP file.

Specs:

  • Impeller: 29mm diameter, 29mm pitch
  • Exit nozzle diameter: 22mm
  • Hull length: 460mm
  • Hull width: ~185mm
  • 9g servo for steering (can use larger servos when adapter plate used)
  • Weight of printed parts: 550g (PLA), 460g (ABS)

Power system:
As you can see in the video, the power system I used was completely over powered. The boat does appear to handle better when it is lighter and a smaller motor would help reduce the weight. Parts used are as follows:

  • 3674 brushless inrunner motor @1900KV. 61A max. Max power 1800w.
  • 2x 2200mAh batteries, 25C.
  • 120A watercooled ESC

Improvements in this version:

  • Deeper v - skips over the waves less
  • 30mm longer and 20mm wider
  • Better sealing lid with only 2 screws for easy/quick opening.
  • Properly designed using surfacing tools in Solidworks 2016
  • Parametric thickness of hull and easier re-dimensioning of hull shape.

Ideas to improve for the (maybe) next version:

  • Add printed ducts inside of the hull. Then have it use the venturi effect to suck any water out of the bottom of the boat this way the boat would pump out any water that got in when the pump is running
    • Thats about it. I'm pretty happy with it as it is. Suggestions for improvements are welcome :-) All the CAD files are included here including a PARASOLID export to help make improvements or derivatives easy.

UPDATE: I've now added a bash plate to the nozzle. The new file is called "nozzle & bashplate.stl" and can be found in the download.

Materials and methods

Can be printed in ABS PLA or PETG. ABS is my preference. If you are using PLA try to keep the fan off for the hull parts or else the sharp hull corners tend to lift a little.

Use 0.15mm layer height for the impeller. Print with supports enabled. For all other parts I used 0.25mm layer height with a 0.4mm nozzle on my Original Prusa i3 MK2.

The nozzle takes a 3mm inner, 4mmor 5mm outer diameter teflon tube as a bushing for the shaft (check the last two pictures above). I cut 5mm off some spare bowden tube and used this. Teflon is a very durable and low friction material - perfect for use here.

Bill of Materials:
- - Weight of printed parts: 550g (PLA), 460g (ABS) you'll need a bit more than that because of required support material
- M3 misc screws
- 6x self tapping screws 10mm long or so
- 1x 105mm long, 3mm stainless steel rod as driveshaft. To mount the impeller securely I ground a flat on the shaft, sanded the rest of the area that was doing to contact the impeller and super glued it in place.
- 1x 623RS bearing (623ZZ is also fine but rubber seal is of course better when water is involved)
- 1x 750mm of servo pushrod wire (most of it is used as a water intake screen)
- 1x flexible coupler to go from motor to the driveshaft. I used 3 to 5mm universal joint adapter. Most 36mm diameter motors use 5mm shafts. I would recommend a universal joint which can be found for $1-2 on aliexpress. You could print your own universal joint or direct coupler (both are printable and included in files).

Electronics:
- 1x 9g servos

- 1x Motor + ESC
I'll be using this motor: https://hobbyking.com/en_us/turnigy-xk3674-1900kv-brushless-inrunner.html
And this ESC: https://hobbyking.com/en_us/hobbyking-120a-boat-esc-4a-ubec.html

My reference told me to pick a motor/battery combo that delivers up to 20,000 rpm and can handle about ~75A continuous. Refer to: https://www.kehrer-modellbau.de/en/kmb-jet28/jet-drives/kmb-jet28-rev.-3-with-short-steering-nozzle

Included in the files are mounting brackets for 36mm and 28mm diameter inrunner motors as well as a mount for common airplane motors using 19mm hole spacing.

- 2x lipo batteries. You'll want two: one to place in either side of the motor for balance. I will use 2x 2200mAh 3S lipo batteries. I like to use velcro to hold batteries in place. I feel its a bit on the heavy side so lighter batteries wouldn't hurt
- 1x transmitter/receiver set. I will be using my Flysky i6 setup.

If you have any questions, please do ask!

Documents

Issues

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Comments

57b9226fe34a7877fb8f481e97b9fe99?default=blank&size=40David Bowers added this to the rc jet boat collection ago
Bf6f2270fe703ae44ce35e53fbe2da7c?default=blank&size=40BokC added this to the RC collection ago
Bb75da4d7e6f900f5f6d759169083cb1?default=blank&size=40Jotham B commented ago

Ok. Strange, if I click it, it just goes into edit mode.

Could you PM me the part or publish it on youmagine and link it here?

219b355d08034aa3a88311a3dade2092?default=blank&size=40abitencrypted commented ago

Hi Jotham,

No link to collaborate at my end. I'm thinking collaboration is something that you will have to action from your end and an invite will come to me.

Bb75da4d7e6f900f5f6d759169083cb1?default=blank&size=40Jotham B commented ago

Thanks howard, that'd be great. If you click the "collaborate on this design" near the top right of the page I think it will let you edit the page, or it might send a approval request to me. Then you can add the STL file.

219b355d08034aa3a88311a3dade2092?default=blank&size=40abitencrypted commented ago

Hi Jotham,

I've had to modify the motor mount to take a Turnigy Aquastar water cooled 3660-1700KV. I have the modified STL to share but not sure how to post it here. Let me know if you want it. Maybe PM it to you.

Howard

B2d987bcc85ee8aa33c9443404291371?default=blank&size=40Mahdi Khoshnood added this to the 3d printer collection ago
F297325b8076532b43f02d927b7762bd?default=blank&size=40amidar added this to the RC collection ago
219b355d08034aa3a88311a3dade2092?default=blank&size=40abitencrypted printed this ago
Carousel thumb wp 20180909 13 16 28 rich
Printed on:
original prusa i3 MK2
Result:
Used original Prusa i3 MK3 (not available in available options) Excellent. Really good job made of the design by Jotham.
Feedback:
No issues printing this model. I added a few 1mm thick tabs to help align the hull sections when gluing with supper glue. See photo which is ready for finishing and painting.
Bb75da4d7e6f900f5f6d759169083cb1?default=blank&size=40Jotham B commented ago

I generally use about 20% infill and set it to use 3 perimeters. This results in almost all the hull being solid. I use super glue to join the parts. I did one in ABS and used acetone slurry which works very well. Cheers : )

219b355d08034aa3a88311a3dade2092?default=blank&size=40abitencrypted commented ago

Great work.

I've been 3d printing for 9 months, the last 3 with a new Prusa i3 Mk3. I thought I would give your boat a try. Wish me luck:-)

I hope you don't mind if I ask a couple of questions relating to a PLA printed version -

1. What percentage in-fill did you use?

2. What adhesive would you recommend for bonding the hull parts?

Thanks

Howard

E5771b0008152dc343d1a898da5272a2?default=blank&size=40sph130 added this to the Print This collection ago
F6c2b80053cf43c103a4d15a2e036e27?default=blank&size=40marcofaby.73 added this to the Modellismo collection ago
D2c949762d189f0b75a915817b3b7adc?default=blank&size=40printerz added this to the Drone collection ago
Bbf00b3825fd578fcafe2d1f6088da8c?default=blank&size=40moroziller added this to the Misc collection ago
Bb75da4d7e6f900f5f6d759169083cb1?default=blank&size=40Jotham B published this design ago