M-Jet 35 Performance

[@mjetdevelopment]

The M-Jet 35 development has been finished! Buy the files here and make your boat fly: www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-35-3d-printable-jet-pump-for-rc-boats

[@107Anderson]

wow man u have done such magnificent work, ive been loving ur work ever since i discovered ur channel, cant wait to see that new boat go flying

[@jansvasta2146]

Wow, you've done amazing work optimising your design! What you have achieved is truly impressive, hats off to you!

[@mjetdevelopment]

Díky!

[@mattyceks380]

excellent work Stepan i honestly think that this is going to revolutionise the jet pump industry reinvigorate it so to speak imagine what sort of gains this could do on a 200+hp jetski

[@mjetdevelopment]

Thank you very much! One day designing a jetski pump would be my dream job.

[@ricardooreamillan3674]

impressive numbers! great job!

[@booodazzz]

Amazing work!

[@iandrake4683]

Impressive!

[@othellosmodellbau9591]

hi, aside from the impressive work, could you elaborate on how you calculated (or measured) output power?

[@mjetdevelopment]

1/2 m*v^2 where m is mass flow per second, v is exit velocity. This gives kinetic energy which is added to the water flowing through the pump per one second.

[@joshuahewetson4018]

My plan is to scale your design up and install it on a pontoon raft i am building. not for super speed but for a easy way to move about the bay

[@fastbike175]

I want to scale it slightly to power a kayak, let us know how your build goes.

[@michaelklopper9168]

Hi, im very keen to print a boat but i have a query if i buy the M-jet boat plan on csgtrader does that include the print files for m-jet 30, m-jet 35 and m-jet 60 jet drive files. btw awesome the thrust bench test/dyno you build.... very creative and genius.

[@mjetdevelopment]

Thanks! The M-Jet Sprint files do not include any additional files for my other projects. The M-Jet Sprint is a complete boat and there is everthing needed to build it including the integrated pump. Other pumps are not included.

[@michaelklopper9168]

@@mjetdevelopment does the M-jet 35 you testing fit the sprint hull, would like to test it as well

[@mjetdevelopment]

@@michaelklopper9168 Files for the M-Jet 35 are not and will not be available, because I am planning to sell this pump physically. But it would be way too big for the M-Jet Sprint hull anyway.

[@michielstuip3547]

Well done! Need to build such a rig too some day. Than again thrust is nice for big and heavy models, the exit nozzle speed is the property for true hull speed! 54kmh is a good achievement! For me the most difficult challenge is to increase this exit nozzle speed at the cost of thrust, to keep the power consumption equal! There might be more speed potential in your drive too, who knows!

[@mjetdevelopment]

Exactly - exit velocity is the "limiting" factor for top speed! I found the thrust stand very practical and easy to use, I highly recommend building it. Now it sounds crazy that during last 9 months I measured and calculated 141 different setup combinations, which made the excel sheet quite huge...

[@michielstuip3547]

@@mjetdevelopment 141...that is amazing! It is if you are looking for the holy Greal, hard to find or it does not exist at all!? ;) Did you test your spaghetti-nozzle against the equal conventional nozzle?

[@mjetdevelopment]

@@michielstuip3547 Yes. I did not want to go in-depth in this video yet. But the 6-path nozzle is truly much better. Aganist a regular nozzle with the same cross-sectional exit area, the 6-path nozzle achieved 23% better efficiency (in that development phase it meant going from 30% to 37% pump efficiency).

[@mjetdevelopment]

@@michielstuip3547 Basically there are two key improvements aganist a "regular" pump. The first one are single blade impellers, second one is the 6-path nozzle. Together with other little things like progressive pitch blades, slightly mixed flow wear rings and progressive diameter hub, this doubled the efficiency.

[@eric1052]

Damn I can't wait to see how this pump performs with a nice boat

[@mjetdevelopment]

Working on it!:)

[@0078577]

Will there be a 40mm version, do you plan on incorporating a grease nozzle & cooling inlet? Looks like the servo mount is not for a standard size servo, if thats the case can there be an option for a comventional pull rod. Is this compatible with 40mm motors (4082 1650kv) for e.g?

[@mjetdevelopment]

40mm version maybe in the future, it is not on the list yet. There is a grease port for the main bearing (the stator bearing does not have one), cooling inlet and outlet are both there. The servo mount is for a mini servo, it was designed around the sawox sw-0250mg, any similar size servo will fit. The servo can be slided up and down to compensate for any servo rod missalignment of different servos. Conventional pullrod would be very difficult to incorporate because of the rail sliding 6-path nozzle mechanism. Any 36 or 40mm motor can be mounted, including the cooling jacket.

[@0078577]

What motor was used in this video?

[@mjetdevelopment]

@@0078577 Hobbystar 3674 1200kv brushless on 6s with 120A Turnigy aquastar marine esc with zero degree timing

[@inspire1453]

Please I need that pump... Can i psy for stl file

[@sepultura1981]

very good! Cheers!!!

[@favian3380]

You should make it a 3d printed hull with pump and sale like m-jet sprint boat

[@mjetdevelopment]

Maybe some time in future I will make M-Jet Sprint MK2, who knows... But now I want an ultralight cf hull and 4G acceleration!

[@YOUNGSTERS-JETS]

my notification bell is not working :( Great job, 1.8kw with 7.4kg thrust and fast velocity, looking forward to seeing it in boat, very well done :)

[@IvanJoel]

Does it matter that the pump did not have the nozzle in the water when you measured the thrust?

[@mjetdevelopment]

It does. If I submerged it, thrust would be lower, because the surrounding water adds resistance. But when the actual boat is driving, as it gets on plane, the pump rises out of the water completely as well. So this is the correct and realistic way to measure it.

[@DeMoN_Ek9]

I wish there was more “aftermarket” support for RTR rc boats. I love the jet boats especially the little Pro Boat Sprintjet 9. They are terrible stock. Maybe there’s a market for a better impeller and nozzle that would make the stock thing decent speed?

[@mjetdevelopment]

I get what you are saying, in my opinion and experience most of the cheap small pumps, impellers or other parts available are not very good quality. Did you convert your boat to brushless?

[@DeMoN_Ek9]

@@mjetdevelopment Sure did lol. I did the dynamite 6000kv 2 in 1 esc motor for more space and make it lighter. If you made a little sprintjet like your bigger design but for 20-24mm size brushless it would made pro boat look light a Walmart toy hahahaha! Also if a pump had a pinion and spur gear setup to swap the ratio out, would that allow us to adjust the speed/acceleration for the motor rpm? Or like a 2-3 speed transmission would be a sight to see!

[@mjetdevelopment]

@@DeMoN_Ek9 A multi speed transmission would probably be overcomplicated, but a single pair of gears might bring some advantages. Reason is, brushless motors around the 3660 size or similar achieve the most power output at 50000 RPM. But the pumps at a corresponding size need only 25000 loaded RPM maximum. So a 2:1 gear ratio would allow for using a bit smaller motor and using its full power potential while saving weight and possibly increasing torque.

[@mjetdevelopment]

@@DeMoN_Ek9 Maybe one day I will design a smaller boat, who knows:) anyway if you have a 3D printer, you might be able to design some upgrade parts yourself?

[@DeMoN_Ek9]

@@mjetdevelopment I’m a welder/fabricator/ machinist and work in a prototype shop with all the fun machines. Unfortunately we cannot make things at work for ourselves. We use Soildworks for designing/modeling.

[@ChampTruex]

cant wait to rock that! lol

[@rogierpluylaar3610]

So u are changing 60 bucks for a fun thing that isnt realy prove

[@mjetdevelopment]

Could you please explain more in detail what you mean?