Gavin "Mini Me" vs. X-Scooter Sierra (standard).

[O-ring]

The only scooter I have ever used is the X, so I can provide no comparative information.

One of the main reasons I picked the X was the motor Technology used. I own a machine shop. I'm surrounded with electric motors, spindle motors, servo motors, brush type DC, brushless DC, brushless AC, etc. ~100 motors. I've had the opportunity to work on, repair and replace lots of motors

Brush Type DC motors are a very reliable, mature technology, but they do require maintenance of the brushes.

Brushless DC motors require an electronic controller. Some see this as a "failure point" I see it as a benefit.

This controller permits "soft starts" or slow application of power. This is easier on the diver, and the drive train, lower peak torque.

This also permits the "electronic clutch" the X scooters have. If you jam the prop, the controller detects the rapid loss of RPM, and cuts off the power. This means the mechanical clutch is almost never actuated. The mechanical clutch in scooter drives can require service, and can fail, nice if you can avoid tripping the clutch.

Lastly the motor controller permits the "Trigger" throttle control now being included on the current X scooter. I haven't yet tried this feature, but I can upgrade mine by replacing the motor controller card. Very cool.


Tobin

One additional point to Tobin's post - do NOT try to stop the X prop on dry land with your bare hand. Don't ask how I know this.

 

[Vie]

Great info, thank you Tobin.

 

[cool_hardware52]

One additional point to Tobin's post - do NOT try to stop the X prop on dry land with your bare hand. Don't ask how I know this.

Whatever you say lefty.....

 

[Vie]

http://www.gavinscooters.com/specifications.htm

http://www.gavinscooters.com/faq.htm

http://www.silent-submersion.com/faq/index.htm

Ah, thank you.

I am confused though: Rodney says that "Industrial Polyethylene (HDPE) pipe is used for the hull of the UV scooters. This pipe is good to 400 feet, actual dives as deep as 616 feet." He basically advocates using HDPE for the body and UHMW for the nose and back end.

George says he does not use HDPE for the body as "In both the HDPE and PVC (nose and tail material) versions, the flex will become an issue in the 900 foot range, which becomes a moot point due to the risk to the seal and the chance of leaking around the o-rings if the body flexes (a major issue at all depths with HDPE bodies, which we do not use for that reason). Between 450 and 650 feet, the flex in the PVC bodies is between 5/100 and 8/100 of an inch." According to George, "PVC is the best body material due to its rigidity" and he only uses HDPE for the nose and back end.

??

 

[JeffG]

Ah, thank you.

I am confused though: Rodney says that "Industrial Polyethylene (HDPE) pipe is used for the hull of the UV scooters. This pipe is good to 400 feet, actual dives as deep as 616 feet." He basically advocates using HDPE for the body and UHMW for the nose and back end.

George says he does not use HDPE for the body as "In both the HDPE and PVC (nose and tail material) versions, the flex will become an issue in the 900 foot range, which becomes a moot point due to the risk to the seal and the chance of leaking around the o-rings if the body flexes (a major issue at all depths with HDPE bodies, which we do not use for that reason). Between 450 and 650 feet, the flex in the PVC bodies is between 5/100 and 8/100 of an inch." According to George, "PVC is the best body material due to its rigidity" and he only uses HDPE for the nose and back end.

??

Sometimes...its good marketing to be different. How many 400+ ft dives are you going to do?

 

[Vie]

How many 400+ ft dives are you going to do?

None. Otoh, Mr. Irvine claims that "body flexes" is "a major issue at all depths with HDPE bodies, which we do not use for that reason..." I guess it's a moot point as the two scooters I am seriously considering do not have HDPE bodies. I was just curious about the discrepancy between Rodney's and George's claims/views/opinions - any one care to comment?

 

[JeffG]

None but George claims that "body flexes" is "a major issue at all depths with HDPE bodies, which we do not use for that reason..."

I'll go back to one of my original comments.


Claim...High science.

 

[Vie]

Lol.

 

[nadwidny]

So what was your conclusion from your evaluation of the X-Scooters, standard Gavin, Farallon and Mako?

I'm not sure I want to post on Scubaboard and carry the stigma that entails but what the hell...

I am one of the few that have actually owned 3 of the major brands of scooters. I have had the SS with the short body and long bodies, the Gavin with short, medium, and long bodies, and the X with short and long bodies. Here are my thoughts. Keep in mind that I am just the driver and don't care to get into the minutiae of the engineering.

From a driver's perspective for short body work I would much rather drive an X than I would an SS. I would much rather drive an SS than a Gavin. I have found the X to be faster than any SS or Gavin I've run against.

For long body work I would much rather drive an SS than a Gavin. I have not had enough time on the X long body right now to place it. For pure driving pleasure it can't be beat but I just haven't had a chance to test the X's batteries for long dives.

I've also been privy to an SS vs. Mako contest. The Mako was so far behind it wasn't funny.

 

[wb416]

One additional point to Tobin's post - do NOT try to stop the X prop on dry land with your bare hand. Don't ask how I know this.

Any pics of the results?