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
New pair of stainless steel impellers from Sculpteo arrived. The vibration is smaller than before but still not perfect as you can see - I can only get to small throttle before the coin falls down. And yeah, I dont always catch the coin XD
@@mjetdevelopment doesn't the 6 path nozzle restrict flow more than a conventional nozzle? I mean, it does make for a nice lineair flow but there is probably way more wet surface in the 6 path design, creating more drag?
@HJ L The 6-path nozzle performs way better than the convetional one (I have already measured it many times)! Because 1) It is much shorter, like 2 or 3 times shorter than the conventional one, 2) the flow path is much straighter and simplier because the water is not forced and bent back into the geometrical center after passing the second impeller (second impeller has quite a big hub). In the future I will probably make a bigger video to sum everything up!
It is not:) this is only about 10% throttle and the coin falls. But at least it is better than before, and thats the point. Also, for me this is a new nice objective way to compare different impellers for balance
@@mjetdevelopment ... This is just a thought from a layman... Your propellers;... prop shaft run in a close fitting parallel tube... If this was cone in shape;... proportional to the volume of water being pushed down to the exit point in stages... If somehow it could be internally like planetary gears;... that the rotational speed of each propeller increased... Increasing pressure on its output side;... thereby pulling more water in on the inlet side... This maybe a dumb idea from a non engineer... Just me thinking outside the box...?
@@ElTelBaby I get how you mean it. In theory it could work but there is not really any reason to do it. Because a very similar effect can be achieved by just increasing the pitch of the second impeller. Also obviously it would add so much complexity..simple solutions often work the best
@@ElTelBaby A better way to do this would be to make the second impeller rotate the opposite way. Then it might be possible to remove the first row of stator vanes while keeing all advantages of the two stage pump. And this is what I would like to do if I could, it is nearly impossible at this scale though
@@mjetdevelopment ... After I posted... That complexity bit did start to run though my out of box mind;... especially as U R making such a small engine...
I'd really like some advice Stepan. I've printed almost all of Depronised's CB-90 at 150% or 1/14th scale. The last pieces I need to print are the jet drives. Depronised's jet drive design is now over 4 years old, and in that time I;ve watched you make some giant leaps in jet drive design. My question is which of your jet drives/impellers/motors,esc would you recommend for a 120cm/4 foot hull, bearing in mind it has a twin jet drive set up? TIA
Wow nice project! From my designs, two M-Jet 30s will power your 120cm boat well if high speed is not your main goal. They can achieve over 7kg of thrust together and if your boat is not too heavy (how is the weight?) it should be a pretty good setup. www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats
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
New pair of stainless steel impellers from Sculpteo arrived. The vibration is smaller than before but still not perfect as you can see - I can only get to small throttle before the coin falls down. And yeah, I dont always catch the coin XD
😃
Again a step forward in developement! Well done! I am also interested in its efficiency. I woke up the "jet calculations" topic on RCG again ;)
Thats awesome!!, even with a small vibration, its quite a change!, great!
im more interested in efficiency. I vibration is just part of the equation.
Vibration is not a problem for efficiency, it is a problem for lifespan and stability of the system overall.
@@mjetdevelopment your explanation explains allot!
@@mjetdevelopment 👍🏻
@@mjetdevelopment doesn't the 6 path nozzle restrict flow more than a conventional nozzle? I mean, it does make for a nice lineair flow but there is probably way more wet surface in the 6 path design, creating more drag?
@HJ L The 6-path nozzle performs way better than the convetional one (I have already measured it many times)! Because 1) It is much shorter, like 2 or 3 times shorter than the conventional one, 2) the flow path is much straighter and simplier because the water is not forced and bent back into the geometrical center after passing the second impeller (second impeller has quite a big hub). In the future I will probably make a bigger video to sum everything up!
Now that is almost perfect balance rotor...
It is not:) this is only about 10% throttle and the coin falls. But at least it is better than before, and thats the point. Also, for me this is a new nice objective way to compare different impellers for balance
@@mjetdevelopment ...
This is just a thought from a layman...
Your propellers;... prop shaft run in a close fitting parallel tube...
If this was cone in shape;... proportional to the volume of water being pushed down to the exit point in stages... If somehow it could be internally like planetary gears;... that the rotational speed of each propeller increased... Increasing pressure on its output side;... thereby pulling more water in on the inlet side...
This maybe a dumb idea from a non engineer...
Just me thinking outside the box...?
@@ElTelBaby I get how you mean it. In theory it could work but there is not really any reason to do it. Because a very similar effect can be achieved by just increasing the pitch of the second impeller. Also obviously it would add so much complexity..simple solutions often work the best
@@ElTelBaby A better way to do this would be to make the second impeller rotate the opposite way. Then it might be possible to remove the first row of stator vanes while keeing all advantages of the two stage pump. And this is what I would like to do if I could, it is nearly impossible at this scale though
@@mjetdevelopment ...
After I posted...
That complexity bit did start to run though my out of box mind;... especially as U R making such a small engine...
I'd really like some advice Stepan. I've printed almost all of Depronised's CB-90 at 150% or 1/14th scale. The last pieces I need to print are the jet drives. Depronised's jet drive design is now over 4 years old, and in that time I;ve watched you make some giant leaps in jet drive design. My question is which of your jet drives/impellers/motors,esc would you recommend for a 120cm/4 foot hull, bearing in mind it has a twin jet drive set up? TIA
Wow nice project! From my designs, two M-Jet 30s will power your 120cm boat well if high speed is not your main goal. They can achieve over 7kg of thrust together and if your boat is not too heavy (how is the weight?) it should be a pretty good setup. www.cgtrader.com/3d-print-models/hobby-diy/other/m-jet-3d-printable-jet-drive-for-rc-boats
-20 korun :D
Už jich tam napadalo hodně kdybych to nelovil magnetem:)