Jet Propulsion?


#63

Has anyone good experience with java prop ? I need a design for a impeller ? I haven’t a clue what I’m doing


#64

David, I used JavaProp for our propellers, but we moved to Impellers for various reasons.

Check out this impeller software, hope it helps!
https://www.caeses.com/blog/2015/parametric-impeller-design/

Here is a recent photo of my impeller drive and floating waterproof remote control



Propellers and Ducts
Another Jet Propulsion Try
#65

the inlet ducts look like they could be a possible hazard for fingers and toes, maybe mesh ?


#66

The impeller is tucked way back in there but ya, we are test with intake and will add more protection and see what type of flow/thrust we lose each step of the way as we protect it more and more with grills. Thanks DavidC!


#67

It looks awesome. Whats up with the foil? Why did you make it so long (front to back) instead of making it wider (left to right)? Just wondering about your thought process.


#68

Hey thanks Max!
We don’t make foils, this is off the shelf. Photo angle may be deceiving, its the same length as our Liquid force foil fish, just the wings are larger deeper and Wider for more lift/stability at slower speed. Its an SUP foil Max.

Keep up the great work on your end also, you got lots of great things going on its looking really good!


#69

Have you ridden this setup (or any of the others) yet or is it still in the testing phase?


#71

We have not ridden this particular setup yet but within a couple weeks will be up and out! We rode reduction gear setup but thats not the direction we wanted to build as its pickled with extra parts, costs and issues in our opinion :slight_smile:


#72

hi~
I started making jet surfers two years ago.
Neither belt type nor chain type could stand.
The gear was the most durable.


#73

Protototype 1 Version!
Eventually, the motor dies!


#74

That’s wicked!
Its so awesome to see everyone’s designs and ways to create things! Keep up the great work Sungmok!


#75

Difficult Setup. These motors for sure do not run exactly same speed. Did you Monitor the current on each motor? In such setup it is good to have the motors connected with one way clutch to prevent they are working against each other.


#76

Agreed, if you order two motors with same KV they are NEVER the exact same, if one china man puts one more wind or 10 more on a motor it will be different and two motors will definitely be fighting. I full agree you can get little one way clutches which would resolve most of the issue, and the one motor doing most of the work starts to get bogged down the other motor will be there to support and add torque to bring RPM back up.


#77

I dont agree. If you miss one winding the motor is scrap, because of small number of windings. If there is no load, it could happen that one motor does not contribute anything, but hey, this should not damage anything. The ESCs could cause much more load difference than the motors. The windings seem ok to me. This damage looks more like a thermal and RPM overload of the rotor, but who knows?


#78

do you use this type of coupler for the impeller? looks like flex, the impeller does not touch ?


#79

Yes, the one in the photo is a flex coupler but we have NON flex couplers for shaft during operation.


#80

I also conclude that the motor died from an unbalanced condition!
It is likely to be possible to apply the one-way bearings.
I gave up because there would be too many war of attrition and too short a run in time.
730KV 12S Gear ratio 4:1 Dual Motor Gear
Waterpet impeller 96 MM
Thrust collected only data from one test to 40 kg.
Single-motor thrust 30 kg under the same conditions


#81


#82

Now that is a serious ride!
Is there a jet nozzle for that, what does it look like?
Wicked!


#83

I just posted video on how to get a custom aluminum impeller etc… and water intake cone @DavidC

WATCH VIDEO BELOW

3D printing company for aluminum Props and Impellers: https://i.materialise.com/en


How to get a good impeller (for jet propulsion)