Electric Jet Motor

[silverramp]

I recently found this company, ma-3d, who is designing and selling electric jet motors that can be used with 8kw, 15kw or 25kw motors. The whole 3rd gen kit weights about 10kg. They are working on a 4th version with a reversing bucket, and they sent me this render so I figured I'd share. They are using servos to control the bucket and the steering.

I'm dreaming about building an inflatable boat around this jet, and curious if anyone knows anything about this or other electric jets, or has any other thoughts!

 

[wpns]

Nice render, and an order of magnitude too small for what I would want, but I’m a big fan of jets, and I really want this to succeed!

 

[BobR]

This company is producing electric jet drive boats using Zerojet drive units.
I have no affiliation with them.

E JET - Highfield Boats

www.highfieldboats.com

 

[silverramp]

This company is producing electric jet drive boats using Zerojet drive units.
I have no affiliation with them.

E JET - Highfield Boats

www.highfieldboats.com

Ya, I've seen them, super pricey boat and not sure you can buy a single motor/jet. But seems like more or less the same drive, plus a heat exchanger.

One of the problems I find is that there's lots of marketing material on it, especially with music. But not a not of just performance review and actual noise of the electric jet in operation.

 

[wpns]

Ya, I've seen them, super pricey boat and not sure you can buy a single motor/jet. But seems like more or less the same drive, plus a heat exchanger.

One of the problems I find is that there's lots of marketing material on it, especially with music. But not a not of just performance review and actual noise of the electric jet in operation.

Wow, only $36K, not awful considering the price of other electric boats out there. But, as you say, no specs, range, speed, all those minor details. And 5 people? Kinda doubt that....

I kinda still want one. Not that I can afford it, but I kinda still want one...

 

[silverramp]

Wow, only $36K, not awful considering the price of other electric boats out there. But, as you say, no specs, range, speed, all those minor details. And 5 people? Kinda doubt that....

I kinda still want one. Not that I can afford it, but I kinda still want one...

Think it's 18kw, 5kwh

 

[wpns]

Think it's 18kw, 5kwh

So 17-minute runtime? Never mind, the big island is 1/2 hour away.

 

[silverramp]

So 17-minute runtime? Never mind, the big island is 1/2 hour away.

To be fair, you don't have to go at full throttle

 

[FishHog]

Jets are very inefficient running on fuel, I can’t imagine being viable for long on batteries
Love jets but just don’t see how they can be efficient enough for real use

 

[silverramp]

Jets are very inefficient running on fuel, I can’t imagine being viable for long on batteries
Love jets but just don’t see how they can be efficient enough for real use

Totally something I've wondered about.

Couple notes, zero jet in an interview suggested that they are better than, or at least equal to, their electric outboard at higher speeds, (no drag), but lousy at low speed. They also aren't silent.
So it might pair well with a trolling motor?

2nd thing, it's direct drive and you makeup some energy vs an outboard in that respect.

 

[yabert]

2nd thing, it's direct drive and you makeup some energy vs an outboard in that respect.

Except if your outboard is also direct drive like many electric outboard.
Even without direct drive and with a set of bevel gear, you lose what? 5% efficiency at max.

I suspect that the fast rpm propeller of MA-3D jet is way less efficient than the low rpm propeller of an E-outboard.
All those small outrunner motor have to spin really fast in order to output kW.
Example, the 25kW is rated at 35Nm max, so it need to reach 7000rpm to output that much power.
I don't see how a propeller can move water efficiently at that speed.

Look at Torqueedo, e-propulsion or other, they all use low rpm motor/propeller combo (1000-2000 rpm).

 

[silverramp]

Except if your outboard is also direct drive like many electric outboard.
Even without direct drive and with a set of bevel gear, you lose what? 5% efficiency at max.

I suspect that the fast rpm propeller of MA-3D jet is way less efficient than the low rpm propeller of an E-outboard.
All those small outrunner motor have to spin really fast in order to output kW.
Example, the 25kW is rated at 35Nm max, so it need to reach 7000rpm to output that much power.
I don't see how a propeller can move water efficiently at that speed.

Look at Torqueedo, e-propulsion or other, they all use low rpm motor/propeller combo (1000-2000 rpm).

My limited understanding is that outboard transmission loses are closer to 10-15%. Haven't seen any higher power direct drive electric motors, do you know of any? Would be very curious.

My understanding about the impeller in a jet is that it runs at much higher rpms than the propeller in a standard outboard. That 7000rpm would be a reasonable number.

However, I'm definitely not a boat engineer, so good chance I'm wrong!

 

[yabert]

Haven't seen any higher power direct drive electric motors, do you know of any?

Sure.

X Series Electric Outboard Motor

X Series Electric Outboard Motors 40kW 20kW 12kW Clean · Quiet · Powerful · Easy-to-Use X Series ElectricOutboard Motors 40kW 20kW 12kW Clean ·

www.epropulsion.com

Cruise – Electric Outboards with 6 to 25 HP – Torqeedo

Torqeedo Cruise outboard motors are state-of-the-art electric drive systems for boats up to 10 tons. With a respectable performance of 6 to 25 HP.

www.torqeedo.com

 

[silverramp]

Sure.

X Series Electric Outboard Motor

X Series Electric Outboard Motors 40kW 20kW 12kW Clean · Quiet · Powerful · Easy-to-Use X Series ElectricOutboard Motors 40kW 20kW 12kW Clean ·

www.epropulsion.com

Cruise – Electric Outboards with 6 to 25 HP – Torqeedo

Torqeedo Cruise outboard motors are state-of-the-art electric drive systems for boats up to 10 tons. With a respectable performance of 6 to 25 HP.

www.torqeedo.com

Ya, seen those, they look nice but rather pricey. I don't believe they are direct drive. The motor has a drive shaft or a belt or something?

I thought the only way to do a direct drive prop was to put the motor in the water, so it's only practical with smaller motors.

 

[yabert]

they look nice but rather pricey

WAAAAYYYYYYYYYYYYY to pricey for what they are.
I'm also looking at an alternative at 15-20% of those price. DIY is the way to go.
I own an affordable (945$) VENTURA T BRUSHLESS MOTOR who do a great job, but it's comparable to 4-5 hp.

I don't believe they are direct drive. The motor has a drive shaft or a belt or something?

No, large motor underwater for sure.

 

[wpns]

Closing in on 50HP, but still a factor of four(?) smaller than I need for a single outboard, and who knows what I'd need for a jet conversion.
Oh, and on the order of 2600# of batteries, which compares poorly to 428# of gasoline and a singe 500# engine versus 3-4 220# engines.

Of course the boat has a swamped capacity of 3500#, so not a lot of margin for passengers and luggage. 8*)

Don't get me wrong, I still want it (though I don't know the price, please don't tell me!) and the options are getting better, but they aren't there yet.

 

[silverramp]

WAAAAYYYYYYYYYYYYY to pricey for what they are.
I'm also looking at an alternative at 15-20% of those price. DIY is the way to go.
I own an affordable (945$) VENTURA T BRUSHLESS MOTOR who do a great job, but it's comparable to 4-5 hp.


No, large motor underwater for sure.

View attachment 276130

 

[silverramp]

Closing in on 50HP, but still a factor of four(?) smaller than I need for a single outboard, and who knows what I'd need for a jet conversion.
Oh, and on the order of 2600# of batteries, which compares poorly to 428# of gasoline and a singe 500# engine versus 3-4 220# engines.

Of course the boat has a swamped capacity of 3500#, so not a lot of margin for passengers and luggage. 8*)

Don't get me wrong, I still want it (though I don't know the price, please don't tell me!) and the options are getting better, but they aren't there yet.

That's definitely a different ballgame than the little 14' inflatable I'm thinking about!

I bet the battery energy density of 5-8 years in the future will make those bigger boats more attractive to electrify.

 

[yabert]

Silverramp, where is the motor in E-Propulsion Pod format

 

[silverramp]

Silverramp, where is the motor in E-Propulsion Pod format

View attachment 276212

Very cool. Assuming you'd need a rudder for these?

 

[ElectricIslander]

How about an electric longtail motor? Just about the most efficient and cheapest way to get energy into the water to make momentum!

 

[BobR]

Jets are very inefficient running on fuel, I can’t imagine being viable for long on batteries
Love jets but just don’t see how they can be efficient enough for real use

My electric dinghy:

 

[silverramp]

My electric dinghy:

Beautiful! Did you build it yourself? What are the specs?

 

[BobR]

Beautiful! Did you build it yourself? What are the specs?

Yes I built it. 10 1/2 ft. strip built fir/epoxy. Adapted from a William Atkin design from the 1940's. It was designed for a small inboard gas engine. Motor is a Minn Kota trolling motor lower unit.

 

[silverramp]

Yes I built it. 10 1/2 ft. strip built fir/epoxy. Adapted from a William Atkin design from the 1940's. It was designed for a small inboard gas engine. Motor is a Minn Kota trolling motor lower unit.

Battery, solar, motor amps/v, speed?