My "MINIRAY" Rov.

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ChaseNoble
Posts: 22
Joined: Jul 18th, 2013, 7:08 pm

Re: My "MINIRAY" Rov.

Post by ChaseNoble »

Does anyone know what kind of motors video ray uses?
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

Cheers for the pics demon. as you say, good referance for ideas.

Chase- the newer videoray uses brushless motors, the originals were brushed/geared.
Heres some info i gleaned off the net.

Thruster Detail:

Brushed geared-
100mm GTO Thruster: Nominal 24v, 77 watt, 1.6A max. VideoRay runs this thruster on the Pro 3 GTO model and produces 7 lbs. of thrust with a 48v supply. Kit includes a housing, motor, shaft, gear set, cartridge seal, propeller, propeller guard set and mounting bracket. $3,595 :lol:

Motor-
brushed-Pittman - 9234E054 19.1 VDC nominal winding with a planetary reduction 3.8:1
Controller - any 2 wire brushed type - Remote Control hobby type, H-Bridge or simple PWM FET if no reverse is needed.
Roughly we can get 6 pounds of static thrust at 90 watts input.
Propellers are available in both left and right hand pitch and are forward thrust optimized so that there is about 30% less thrust in reverse.


Brushless direct drive -
100mm GTO Thruster: 12v, 80 watt, capable of 300 watt. At 80 watts output is 8 lbs of thrust at 300w output 15 lbs. Kit includes a housing, motor, shaft, motor controller, cartridge seal, propeller, propeller guard set and mounting bracket. $3,795 :lol:

Motor -
Kv = 420 RPM/V
Io@ 8v = 0.40 A
Rm = 0.091 ohms
Max continuous power in = 920 Watts
Continuous I = 24A
Max I = 29A
Max V = 98V
Dimensions = 36mm diameter x 60mm Length
Shaft diameter = 5mm
Weight = 290 g
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

Just for fun...

Image

and i added a ring of leds round the camera, think it will cause backscatter but worth a try.
Theres a rubber seal between the camera and the front plate to stop reflections.
The leds only take 100ma so can be driven straight off the velleman board.
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

Hi Folks.
I'm back!!!!
Things went pair shaped last year, my mrs got cancer and had to have her leg amputated below the knee, so naturally I didn't have much time to play with ROV's.
Anyway, things are looking up and I have more play time so I dragged out the old project and found the hull was cracked.
So here's the new hull under production, it's a bit longer than the last one but uses the same components with the addition of the 6mm aluminium end plates that i bored out on the lathe.
I'm still looking for a 70mm diameter acrylic dome with flange to replace the flat faceplate.
I'm also looking at pumped bouyancy on this one.

Image
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

I have aquired 10 lifejacket co2 cylinders that I thought would be just fine for blowing ballast.
a 60g cylinder holds 34 litres of co2 so you'd get plenty of dives (or surfaces) out of a bottle.
But... those 34 litres are squeezed into a small cylinder at 900psi!!!!!!! try finding a pressure regulator small enough for a little rov like mine. :(
If anyone can reccomend one i'd be glad to hear from you. 8-)
I can get flow regulators but that's easy, just a very small jet to reduce the flow rate.
What i'd need is something to regulate 900psi down to a few psi above seawater pressure to blow the tanks.
One way is to have a pressure relief valve that bleeds off excessive pressure constantly but this seems like a big waste of gas even with a very low flow rate.
Suggestions and wacky solutions welcome. :P
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olegodo
Posts: 222
Joined: Aug 30th, 2013, 9:47 am
Location: Bergen, Norway

Re: My "MINIRAY" Rov.

Post by olegodo »

wow.. that's some really bad news about your wife.. I hope you are doing ok now, considering the circumstances.

As for air regulators, maybe you can use paintball stuff.
Air regulators for paintball guns can regulate a 4500psi source down to only a few psi and many of them are also adjustable.
Might be worth some investigation.

Also, there are some small 3000psi 13Ci tanks avalible. These can be refilled easily with compressed air.
http://www.ansgear.com/Ninja_Aluminum_A ... ank-13.htm
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

Thanks for your kind comments Olegodo. She's getting about ok on her prosthetic now, carbon fibre and titanium in that thing, great engineering. I've been tempted to build her a pneumatic one. :D

Thanks for your suggestions on airsoft regulators, maybe i can make an adaptor for 1/2"-20 cylinder to 16mm airsoft.
alternatively I could refill an airsoft tank with nitrogen at work, could probably get a couple of thousand psi in safely enough.

I also have an idea for vacuum operated piston ballast tanks with two oposing pistons, if you pump out the air between the pistons they should draw together and pull in water at each end. the air would be stored in the main hull to be pumped back between the pistons and force the water out again when you want to surface.
I've not seen it done before so there may be something obvious i'm missing.
a_shorething
Posts: 289
Joined: Sep 10th, 2013, 5:26 pm
Location: New Jersey Shore

Re: My "MINIRAY" Rov.

Post by a_shorething »

bigbadbob wrote:<snip>
I've not seen it done before so there may be something obvious i'm missing.
Can't tell you how many times I've said that...

I say go for it!

Downside, you still don't have a system.

Upside: Hobby ROV Legend status!!!! :)

Good luck.
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bigbadbob
Posts: 272
Joined: Nov 28th, 2011, 10:24 am

Re: My "MINIRAY" Rov.

Post by bigbadbob »

8-)

I've spotted a problem with the co2 system, the cylinder would have to lie on it's side and therefore may supply liquid co2 which would boil off and freeze up valves and regulator.

The dual piston idea sounds simple enough to do so will try that first I think.
The only problem i see is that there will be a maximum depth below which the pump can't overcome the seawater pressure and I won't be able to surface.
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sthone
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Joined: Nov 8th, 2010, 9:25 pm
Location: Connecticut
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Re: My "MINIRAY" Rov.

Post by sthone »

bigbadbob wrote: I've spotted a problem with the co2 system, the cylinder would have to lie on it's side and therefore may supply liquid co2 which would boil off and freeze up valves and regulator.
You might be able to get around that with an expansion chamber. We use to run them on our paintball guns to keep our regulators from freezing up too. (most tanks for paintball guns lay on there side also.)

-Steve :sting:
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