How I Made My 4G Sprint Boat Stable

[@mariebaxter473]

Nice to see a young guy doing clever trial and error by observation and getting a good result. Thanks for posting.

[@marx921]

Very good job, man!👍💪

[@hhh5421]

Amazing... incredible improvement bro 🎉

[@hunterjames5819]

Those are some stable turns, nice job!

[@DktheWelder]

Interesting stuff! Time to make a full size one , I’m building a small electric 1 person jet boat

[@mjetdevelopment]

Thanks! Haha maybe one day I will build something to sit into as well:)

[@JeffJackson86]

@@mjetdevelopmentI've been working on my 1:1 boat building with fiberglass. During my research I learned about 1inch foam board covered in fiberglass, that would make a pretty good mini boat Hull.

[@mjetdevelopment]

@@JeffJackson86 Yes, foam core would make things stiffer and possibly lighter. The manufacturing process would be more complicated, but if the goal was to push weight even lower, considering this option would be definitely a good idea

[@JeffJackson86]

Awesome as usual, When i built my 33 inch boat using the Mjet30 I had to use the turn fins as well, same result.

[@MrDesperadus]

Wow this is stable!!! Can you also find a way to stabilise my mental health? My schizofrenia is getting worse

[@Pascal_Robert--Rc_Creations]

You need fins

[@mohdwahama]

See a doctor

[@DeMoN_Ek9]

Coming along very good 👍

[@iwillbat]

Love your boats :) I just finished printing and building your m-jet 3d printed boat, it's awesome on 3s with a 3650kv 3650 motor

[@michielstuip3547]

Well done! Exactly what the big jet-boats do too (except to scale smaller fins). Instead of the 10° up-trim (which also made my boat handle like a charm) of the nozzle true jet-boats have a scoop inside the inlet channel. Check out Jolly Rogers videos on youtube for details > tech-talk!

[@mjetdevelopment]

Oh I can imagine a scoop doing a similar thing! Very interesting.

[@michielstuip3547]

@@mjetdevelopment I have not tried that in a scale model jet! Check the videos I recommend for more info ;) My next hull will have no strakes/spray rails either. I am expecting similar issues...

[@mjetdevelopment]

@@michielstuip3547 I just did not want a scoop because that would be something permanently under the hull level. With the turn fins, I can just remove them if I go to a river, but I am afraid a scoop would break or suck grevel. Also I think spray rails are very diffefent from strakes regarding their effect. The first improvement in handling in my second run was probably caused not by strakes, but by the spray rails. So I would do them if I were to do another hull

[@michielstuip3547]

@@mjetdevelopment : agree nothing should stick under the hull! These scoops do not stick out, it starts in the grade. Check this video: kzbin.info/www/bejne/o4DTeWN7frl1iM0

[@mjetdevelopment]

@@michielstuip3547 I saw this video, but dont see any scoop there? The intake looks more or less like what I have. But putting a scoop for example into the middle part of the grate, to push the boat downwards and more water upwards is definitely something that could be investigated!

[@АнтонПетров-к2ъ]

a wonderful project. where can I download files to create such a water cannon?

[@mjetdevelopment]

Thanks! The M-Jet 35 is not available yet, but there will be all information and a big update about the M-Jet 35 pump in one of my upcoming videos.

[@phaley51]

Awesome, any plans to mod the m-jet 30 to include turning fins?

[@mjetdevelopment]

You can freely download the 4G Sprint Hull files, link in description, and there is a folder with the exact big set of variable sized turn fins which I used in this video. I had the best results with the 20mm set!

[@vortkes4684]

I thought you didn’t want to make the files public in case commercial groups just copied it? Are you going to still produce it?

[@mjetdevelopment]

@@vortkes4684 I am talking about the hull files. These are available now and for free. Regarding the M-Jet 35 pump, yes I said I would not share the files and produce it instead. However, after I started planning the production, thoroughly thinking about this concept and all its consequences, I am changing my mind. I am sorry for all the confusion around the M-Jet 35 and will properly explain everything in my next video!

[@XavierLabarere-sb4qw]

Hello, i'm franchement and after i have s'en yours vidéos, i Will be interested bye à m-jet 35 for drop into à hand made hull. Is it possible to buy one and in this case how many for it and shipping for France.. Thank you so much.. Xavier

[@mjetdevelopment]

Hi, unfortunately I do not sell the M-Jet 35 preassembled as a physical product. I only sell 3D printable STL files which you can buy here and build the pump yourself: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats

[@XavierLabarere-sb4qw]

@@mjetdevelopment hoo, i'm so sad to listen it..because i haven't got accès to à 3d print machine...i look around me if i can find one and i Will be back of you for other information But Thank you so much for your fait answer..Best regards xavier

[@linkspyder]

Hi. What size of turn fins are you using in your 50cm boat? thanks

[@mjetdevelopment]

I tested multiple sizes but got best results with 20mm deep ones

[@linkspyder]

@@mjetdevelopment 😀 Thank you; I think I'm going to implement your solution on this little one (kzbin.info/www/bejne/sJbFqWysoZ1qd9E), that is also turning too quickly; the hull originaly already had the spray rails and the strakes, so I think you turn fins can be a good addon.

[@mjetdevelopment]

@@linkspyder Yes, nice boat, I think turn fins will work for you! If you want, you can even download the exact set I used in this video, check the links in description.

[@dextersxxxxlab]

can you please tell what kind of 6s battery you use. c-rate and capacity and runtime you get.

[@mjetdevelopment]

Graphene lipo 6s 2600mAh 70C. Little over 10 minutes runtime, then I swap for another battery.