The Guppy

[scubersteve]

I couldn't help it.
I started a new one. I saw these 4x2 reducer tees and got this design in my head.
This will just be for pool use. It will use a vertical thruster inside the sleeved 2" section of the cross, a single rear thruster ans a bow thruster for steering. I may have to add a rudder too, I won't know till I see how much authority my bow thruster has.
The dome is from a Harbor Freight fake security camera... thanks to Chriz0138 for that.
So now I have two in the works...
My wife's gonna kill me.

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[KR2_Diving]

Love it! Really REALLY like the use of the Atrium drain as the Thruster Cover! Really wish they were easier to get a hold of here in the UK!

[Tal]

Hey Scuba,

I really like the idea of scaling everything down! I had the same idea with the fake security dome and have one myself, hoping to save a few dollars. I'm curious on your thoughts of depth? I'm not sure if I'll use mine due to my desire to go down as deep as possible , but it seems to be really practical for the guppy!

Are you putting more time into the Guppy, or is Archerfish still your focus

Steve

[scubersteve]

Thanks for the comments. I enjoy the conversations.

I just kinda stumbled on the atrium drains while looking over pvc fittings. I think they are going to work out well.

I'm not sure what kind of depth the cheapie dome can handle but as the pool I'll be playing in is only 10ft deep, I figure it should be fine.

I have been toying with the idea of a smaller one yet. Something 6" or smaller in length using these for propulsion.
http://www.ebay.com/itm/270367248573?ss ... 1423.l2649
but as I have two already started I should probably finish at least one before starting a third.

I have actually been working on both the Guppy and the Archerfish kind of equally. Consequently neither has made great strides. I want to get them both done before the end of the school year because I have been invited to demonstrate them to the students at my kids school during a pool-centered field day. Mine are to "compete" with one built by the high schoolers for an earlier local competition which they won.

http://www.pnj.com/article/20130315/NEW ... ompetition

[scubersteve]

Trying to work on the Guppy...
So I ordered 4 brushed ESCs off ebay from china and after waiting two weeks what do I get???..an Arduino Uno R3...

So I contact them and they say "oops" and will I please send it back. I've already coughed up $47 for these ESCs, I'm not interested in spending more for nothing.
So I told them that if they would cut me a deal on the UNO I would just buy it. 8 dollars later I own it. I have no idea what I'm gonna do with it, but whatever.

My ESCs supposedly reshipped yesterday.

Chinese commerce: both the bane and enabler of my hobbies.

[Tal]

I feel your pain Scuba!

I'm not the most patient when waiting for parts, even if I am not able to use them straight away. I just get excited and want them right away. The Arduino could be a blessing in disguise, however. I remember you were talking about using your RC for Archerfish, so this might be a good opportunity for you to set this one up on Arduino/PS2 control. If you've got the ESC's already coming (lets hope a little quicker this time), you won't need to make any real changes to the hardware.

If you were set on using the RC for control of all your projects, which would make sense, you could just experiment with using the Arduino for basic telemetry, like housing temperature, water temperature (if you're curious), voltage, and so on. It might not be practical for the Guppy but could be a good excuse to familiarise yourself with what Arduino offers, if you haven't already had that exposure. One of the strength's I appreciate of the Arduino, is the ability you have to save your 'sketch' (or code) and just upload it to as many Arduino's you like. With a few projects on the go, you're hard work on one project can be re-used (or expanded on) in subsequent projects by simply uploading code to a new arduino, or even an old one from an obsolete project.

Glad to see you are making progress also and look forward to more updates!

[scubersteve]

Making a little progress...

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[Tal]

Hey Scuba,

I really like what you've done with the strafe motors! Can you describe the bottom seal and latch (or at least that's what it appears to be) and whether you'll be using the opening for an ascent thruster? Is the camera fixed or do you have pan/tilt (or is it just sitting in there for appearance )??

Heaps of progress!!!

[scubersteve]

The camera will be functional but will be stationary. This rov will actually be radio controlled and will only use the tether for video purposes. It's for very shallow use only (15 feet or less)
The lateral thruster is a double shaft 12v motor with two 30mm props. It is located at the front for steering so the vehicle won't move laterally. The advantage over a rudder is that it does not require forward motion turn around.
The vertical tube does indeed house my vertical thruster and there is no access point on this model once it is sealed.
I am going to use flowable silicone windshield sealant on the joints and spray the whole thing with aerosol plasti-dip.
The batteries will be sealed inside but the power will be switched by means of two jumper wires on the outside of the hull.
If I ever have to open it back up I will have to cut along a seam and peel off at least some of the plasti-dip.
I'll let you know how that works out. It was just too expensive to design in a sufficient access port.

The problem I'm having right now is with the 12v brushed 1200 rpm gear reduction motors I bought.
When I ordered my ESCs, they were reported to be able to handle 4-10 nicad cells. When they arrived today though the documentation with them says 4-7 cells. Well I tried the motor and prop combo on 8.4v and the thrust was pitiful.
So I had to rethink... I don't want to risk all 3 ESC s on higher voltage and I don't want to spring for new motors, so I took one apart to see what I could do.
The motors have a three-stage reduction unit and I think I can remove one of them. So now I'm off to the hardware store for supplies to finish the modifications.
I'll let you know what happens.
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[scubersteve]

Well I managed to remove one stage of the gear reduction unit on my motors and thrust picked up significantly.
Since I always order one extra of everything for a spare I figured I would see what would happen if I did run 10 nicads through one of these ESC s... and it ran fine.
Granted these little gear motors can't draw much which helps.
So I decided to risk it and use 10 D size nicads in The Guppy. Between the decreased gear reduction and the increased voltage, this thing ought to really scoot.

Making great strides now.

Front view

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Rear view with tail off

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