Genesis 2.2 vs Seacraft vs Magnus

[Superlyte27]

Last week Karst Underwater Research took my Genesis 2.2 to almost 10,000 feet in manatee along side a Suex XK1. At the end of the trip the XK1 had 17% battery remaining. The Genesis had 49% remaining. All this and more thrust and ease of use.

 

[stuartv]

You have a few errors here at least on the Genesis, not sure in the sea craft.

What errors? I took all that right off the Logic web page.

 

[Jon Nellis]

So, to roll this thread back to what I think was the point of the OP....

...

Genesis - remove cover to charge via external recharge connector - cannot drive with cover off
Seacraft - same

Genesis - magnetic prop coupling
Seacraft - magnetic prop coupling

...

A couple clarifications.
The recharge plug on the Genesis is a waterproof connector. The rubber plug cover is to prevent corrosion of the pins in water. If you lose or leave the cover back at the hotel (like I've done) you can still dive the DPV, as the water will make the connection between the pins to enable the motor controller. Doing that occasionally is not the end of the world, but you just don't want to do that all the time, as corrosion would eventually be noticeable.
Last I heard, the connector on the Seacraft was not waterproof. The small cover for its recharge port provides the seal and if that cover is not installed or sealed properly, the DPV will flood. You are still breaking the hermetic seal on the DPV, just a smaller opening. I'm not sure if it is still that way.


The Genesis uses a magnetic shaft coupling, The Seacraft uses a "wet motor". I would have to really geek out on here about motor efficiency loses due to air gap increase required for corrosion prevention on wet motors, to explain the benefits of the magnetic coupling. I'll just say that they are not the same.



.

 

[Dusty123]

Seacraft has made some updates where an eio connector can be used for lights or heat and they updated there charging port so contact with saltwater isn't an issue. Check their facebook page for current info. Unfortunately the new upgrades aren't backwards compatible with earlier models like mine. Battery is proprietary, USA manufactured probably cause they can't fly them here from Europe. The guy is located in Warren, VT and also services the whole dpv. I have sent mine in to replace a cracked display/ firmware update. Just sent him the lower unit was pretty easy. I have no experience with the genesis so can't comment there. The fixed gear is of no concern in the ocean, maybe has some relevance in a cave compared to infinitely variable. The motor has a soft start to it which can be a bit annoying so if you let off the throttle it takes a few seconds to get back up to speed, can't feather it. If you are scootering through a wreck its not a big deal since you are just crawling along anyway. The post flow stator does what it claims to do. There are two o-rings on the lower unit and one on the top cap that threads to a central rod that runs the length of the unit holding it together. The battery can slide on this rod to adjust the cg in the water and trim weights can be added to, it works pretty good.

 

[Dusty123]

So this is the Seacraft motor and some corrosion had started to form on it. As Jon Nellis pointed out there is a tight gap to maintain efficiency. I imagine some sand got in there and stripped the coating from it. They say this isn't an issue yet and has cleaned up since the picture (photo looks worse than actually is). Adding some wd40 as part of the prop service. Not sure I like this answer for an 8K scooter but we will see.... Also note how much cooling the motor has....

 

[stuartv]

A couple clarifications.
The recharge plug on the Genesis is a waterproof connector. The rubber plug cover is to prevent corrosion of the pins in water. If you lose or leave the cover back at the hotel (like I've done) you can still dive the DPV, as the water will make the connection between the pins to enable the motor controller. Doing that occasionally is not the end of the world, but you just don't want to do that all the time, as corrosion would eventually be noticeable.
.

You're saying you can drive it without the charge port cover. Your website says this:

"if the cover is not installed, the motor controller will not be enabled to run" Here: Genesis DPVs | Logic Dive Gear

That sure makes it SOUND like you can't drive it in the water without the charging port cover in place. That is why I said what I said earlier.

 

[stuartv]

I just saw on the Seacraft website more details about the Future that I didn't see before.

- They have a video showing a guy driving one around in a pool where he is literally completely removing his hands from the handle and letting it just pull him along. When he does that, the scooter maintains speed and does not spin. That seems to be pretty solid evidence that their system for ensuring there is no torque to fight while driving it (i.e. the Post-Swirl Stator System) really does work.

Post-swirl stator system | Seacraft

- In the same vane, they claim that when you stop, the scooter floats with the handle upright. Based on my use of my BlackTip so far, I feel like that would be nice. If I stop and let go of the handle, I would prefer that my scooter stay exactly how it is, in the same orientation, trim, etc.. But, I don't have that many scooter dives, so I'm not sure how valuable that feature really is. I guess it must contribute to the previous point, though. If there is weight that makes the handle turn to one side when you stop, then you'd always be countering that while holding the handle to drive it.

- The Seacraft's built-in computer has an extensive menu system, allowing the user to customize operation. It looks like you can do things like turn off the "soft start" if you want. Or maybe even adjust it to be more aggressive on startup, without completely turning it off.

- Also, the video of the menu system shows an option to Enable a Reverse gear. I don't know if that is real, or one of these features that accidentally got into a marketing video, but engineering never actually implemented. But, it sounds like it could be cool. One of those things where you practically never need it. But, when you do need it, you REALLY need it.

User customization menu | Seacraft

Menu showing Reverse unlock is shown starting at 0:19 in the video in that link. Some info about it shown starting at 1:23.

- They claim the Future is silent. They say it's the quietest DPV on the market. My BlackTip is dang near completely silent. I drove up on a buddy who was stopped in the water, looking around for me. I drove my scooter up from behind him, directly above his head, close enough that I reached down and tapped him after the scooter went over him. He didn't realize I was there until I tapped him. He was wearing a 5mm hood, I think, and on OC. That is how quiet the BlackTip is.

Is the Seacraft that quiet?

Is the Genesis that quiet?

 

[tbone1004]

@stuartv the "norm" is for scooters to have the handles over at 3 o'clock when off. The counterweight helps to control the torque from the motor. This worked fine for the 500w motors in the Gavins and Silent Submerges, but when cranked up wasn't enough and you were having to use your arm to keep the dpv from rotating around. This also has the happy accident that it keeps the handle protected from the ceiling when you're towing it.
When the scooters got more powerful, like the ~1kw motors in the Genesis, Cuda, Magnus, etc. they also get significantly lighter which meant there wasn't enough counterweight to keep them comfortable for extended diving. Even my Viper at ~700w is not comfortable for long periods of time on full-tilt-boogie where my UV26 which has the same motor is perfectly fine since it weighs twice as much. This resulted in many of the manufacturers coming out with torque reducing fins to try to help counteract that rotation. This all occurred 5-6 years ago give or take and IIRC started with a request to Bonex from Edd at Cave Adventurers who basically took the standard shroud strut and turned it into a rudder. Silent Submersion copied. Since the fins are ahead of the prop, and not really in the direct prop wash, their efficacy is a function of linear speed, similar to a rudder, and that's where the stator in the Seacraft is nice since it sits right behind the prop and works better at the low speeds. I'd love to see @Jon Nellis implement some stator type situation in the next generation of the Genesis, but do understand it is a huge undertaking to redo that shroud.

On the reverse gear, any of the ESC's out there can have it enabled, I'm not sure when you would actually use it, but if you use SmartDPV from @Jona Silverstein I believe that can have a reverse gear enabled. I truly can't think of any application for backing up though and it would be very high risk of sucking up the tow cord.

 

[stuartv]

@stuartv the "norm" is for scooters to have the handles over at 3 o'clock when off. The counterweight helps to control the torque from the motor. This worked fine for the 500w motors in the Gavins and Silent Submerges, but when cranked up wasn't enough and you were having to use your arm to keep the dpv from rotating around. This also has the happy accident that it keeps the handle protected from the ceiling when you're towing it.
When the scooters got more powerful, like the ~1kw motors in the Genesis, Cuda, Magnus, etc. they also get significantly lighter which meant there wasn't enough counterweight to keep them comfortable for extended diving. Even my Viper at ~700w is not comfortable for long periods of time on full-tilt-boogie where my UV26 which has the same motor is perfectly fine since it weighs twice as much. This resulted in many of the manufacturers coming out with torque reducing fins to try to help counteract that rotation. This all occurred 5-6 years ago give or take and IIRC started with a request to Bonex from Edd at Cave Adventurers who basically took the standard shroud strut and turned it into a rudder. Silent Submersion copied. Since the fins are ahead of the prop, and not really in the direct prop wash, their efficacy is a function of linear speed, similar to a rudder, and that's where the stator in the Seacraft is nice since it sits right behind the prop and works better at the low speeds. I'd love to see @Jon Nellis implement some stator type situation in the next generation of the Genesis, but do understand it is a huge undertaking to redo that shroud.

On the reverse gear, any of the ESC's out there can have it enabled, I'm not sure when you would actually use it, but if you use SmartDPV from @Jona Silverstein I believe that can have a reverse gear enabled. I truly can't think of any application for backing up though and it would be very high risk of sucking up the tow cord.

So, are you saying that you do experience some torque that you have to counter, when driving a Genesis?

On the Reverse thing, I was just wondering at what point having it in Reverse would cause the prop to pull hard enough to break the magnetic coupling and pull itself right out of the scooter. I guess with the Seacraft stator, the stator might prevent that from happening. At least up to the point that the thrust was enough to break the stator out of its mounting points.

 

[stuartv]

@tbone1004 - it also seems like it would be cool if scooters had a small external weight that you could move. You could have it on the bottom of the scooter for normal operation - so the handle would orient up. But, for example, if you were going to tow it in a cave, you could move the weight to the 3:00 position, so that the scooter would float with the handle at the 3:00 position. Or put it in the 12:00 position, so the scooter would orient with the handle down, between your legs?