OK, lets build a scooter....

[blackice]

to neither pass judgement on a Gavin Scooter or the DIY alternative ....

I would sooo love to have access to a scooter, and given the choice a Gavin would be the preference and they have the history / experience / track record of achieving the amazing.

But the idea of owning a scooter is way cool, but it's an expensive toy! or a complex tool, depending on which way you look at it.

Like any diving equipment, the main thing to ensure is that it will do what you intend it to, if that is assist you out of a 500m deep tunnel or move around coral reefs with easy, I feel the main thought should be to ensure that it is tested and works.

It should be adding to the pleaseure of the diving experience not being a distracting worry.

Enjoy diving - no matter where it leads you.

 

[Windwalker]

Hiya, I know very little about this subject, however I noticed a couple of sites that had "Plans" to build your own DPV and got to thinking, So I dropped by the scubaboard, and low and behold someone is already trying to do their own.

I was just wondering what the stats of said motor would be? Would a High Torque Low output be preferred to a low torque high output motor? For example, Would a 550 inchpound motor chuggin at 2000 rpm be too fast with not enough torque? (These are the specs of a Dewalt Drill, Small motor Planetary gear arrangement, variable speed setting low and high, long runtimes on a small battery)
I looked online for kort nozzles and found a wealth of information, none of it usefull.. I guess the question of Motor power really is governed by what kinda prop is being drivin.

Sorry to butt in, hope not to offend with my ignorance.:idea:

 

[Windwalker]

What about using a Trolling motor? They are already sealed with props and all, they can be got on Ebay for under $100 and come in many ranges of Thrust from 20 - 107 pounds. From what I have been seeing, Most dive scooters have between 20-40 pounds of thrust. That means all you would have to do is buiild a battery compartment and controls.

Just a idea

 

[H2OHead]

I am starting to get nauseous every time someone mentions _IR. The blind faith that people have in someone is amazing and quite reminiscent of back when Jim Jones was in the Kool-Aid business. Just as that “H” company isn’t the only place on the planet that makes filaments glow using a battery, the Gavins aren’t exempt from competition. I think it’s just a supply and demand thing. The Gavins are certainly considered top of the line by many (non _IR folks too I suppose), but scooters are quite expensive no matter who makes them and there just isn’t nearly the demand for them that there is in the other aspects of the diving industry. I say go for it. Try and copy the thing if you want. As for the motor problem you’re having. Go in on a Gavin motor and take it to a motor shop and get the skinny. If you have trouble getting a motor from Irvine, play to his emotion. The guy is 100% hothead and as arrogant as the day is long. Tell him you are going to dissect his motor, get it duplicated with improvements, for half the cost he gets them done for, and there’s nothing he can do to stop you. He’s sure to get mad and send you one for free.

 

[jonnythan]

H2OHead once bubbled...
I am starting to get nauseous every time someone mentions _IR. The blind faith that people have in someone is amazing and quite reminiscent of back when Jim Jones was in the Kool-Aid business. Just as that “H” company isn’t the only place on the planet that makes filaments glow using a battery, the Gavins aren’t exempt from competition.

Blah blah blah. *No one* at all makes these decisions on "blind faith." There is a real thoguht process and real decisions and intense debate behind every single gear choice. Look around the board, all the arguments are there. I've never seen a thread that says "well George says to wear a harness so I do." There are an a** ton of threads debating the merits of a bp with wings, or a long hose, or which tanks to have, or whatever. There are really fantastic reasons behind all of it. I challenge you to think so deeply about your own gear.

Seriously, do some searches on the board. All this DIR stuff is extremely well thought out by everyone who pays attention.

 

[H2OHead]

jonnythan once bubbled...
Blah blah blah.

The expected conditioned response, I see you've memorized your handbook.

The blind faith reference is for the scooter portion of this scooter thread and refers to blindly following a guy who says nobody can duplicate the performance of the rewound motor used in the scooter. To that I say, “unless we’ve issued a patent for the electron and magnetic lines of flux, I will have to disagree”.

The Gavin motor may very well be the most efficient electrical motor ever developed and the envy of all who know of its existence, but I am reserving a small bit of skepticism for myself there. George, undoubtedly the foremost authority on atomic particles and how they interact, may have solved all known issues related to electrical motor design and discovered the key to perpetual motion, but I doubt it.

Not as a means of flattery, but as a means of economics; I suggested buying a Gavin motor and using it as a starting point. This is common in industry where development of products to compete with an existing product line is the goal. I’d say building a scooter comparable in every way to one commercially available, but with far less monetary outlay is one of the goals when homebuilding. Building something in a place other than Irivne’s garage doesn’t necessarily make it inferior, but I won’t continue to try to convince you of that since you seem to have already taken your vow. If you’d put down your checkbook at some point and put on your thinking cap, you’d eventually realize that safe diving can actually occur in the absence of logos like Gavin and Halcyon. I don’t use a Halcyon brand HID light, I actually put a lot of time, effort, and ability into designing my own and built a couple so I’m not on the short list when DIR Christmas party invitations are sent out, but I think I’m actually a better person for that.

I am all for safer diving and collaboration on how to achieve that, but I won’t be sold on the notion that I’m not intelligent enough think “Right” without being told how to do that.

 

[PhotoTJ]

See my related post this thread

I am glad I am not the only one who doesn't follow the _IR path!

 

[GlockDiver]

This is just a thought, but would it be possible to modify an AL80 to have a valve on it such that it could be controlled via a throttle? Thus the thrust would come from escaping air from the bottle? Is this feasible?

 

[Windwalker]

I think escaping air itself would not be that effecient, however harnessing it for a pneumatic Engine could.. Something like this.. http://quasiturbine.promci.qc.ca/QTPneumatique.html

Also, I remember Lego has some Pneumatic engines. I am not saying build a scooter from lego's but, they are pretty buff for their small size and low air requirments.

What about using a Liquid Gas cylinder, that would give you more energy density for expansion (Co2) but the problem would be in keeping it warm and not frozen.

 

[Aquamaniac]

DIR Tec Diver once bubbled...
Not trying to rain on your parade, but you can not copy a Gavin. All who have tried have failed. Yes you can get some of the parts, but the engine, how it is wound and the performance can not be duplicated. George keeps that to himself.

Do you a deal Mr DIR Tec Diver.
I will build an exact replica of a Gavin.
Once its complete you can dismantle it, test drive it, dyno test it, whatever you like.
If at the end of your examination, you can tell me one thing thats differant, or not as good as the Gavin, You will foot the bill.
If I fail, you can have all of my dive gear, including the copied Gavin.
Looking forward to your response
Dave