The Redback - My First ROV

[subn00b]

I outlined the control electronics for my ROV in my intro post here:viewtopic.php?f=9&t=1724
And since I've got most of it working, at least in a basic fashion, I thought I'd turn my attention to the design of the frame.

I plan on using a 4" enclosure from Blue Robotics and I plan to make most of the rest of the frame from 10mm thick sheets of HDPE which I should be able to work with using my very modest tools - a Dremel and a scroll saw. It will have 6 brushless thrusters and the ROV will only need to dive to a maximum depth of 15m.

I think the pictures should explain what I'm thinking, for scale the ROV is 400mm long. The red panels on top will be just thin 3mm acrylic under which I plan to put whatever I use for buoyancy - that space will fit about 30 ping pong balls so that might be the way to go.

redback_01.PNG (13.34 KiB) Viewed 4527 times

redback_02.PNG (19.74 KiB) Viewed 4527 times

redback_03.PNG (12.75 KiB) Viewed 4527 times

redback_04.PNG (13.94 KiB) Viewed 4527 times

redback_05.PNG (19.53 KiB) Viewed 4527 times

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Here's a view with the top off to show the internal vertical pieces:

redback_07.PNG (36.51 KiB) Viewed 4527 times

And the pieces of HDPE and acrylic roughly laid out:

redback_08.PNG (12.8 KiB) Viewed 4527 times

Can anybody see any potential issues? Any advice?

Cheers,
Hugh

[Bindo]

Looks pretty sweet!
Not sure about the ping pong balls though. Not had any experience with them

[subn00b]

Looks pretty sweet!
Not sure about the ping pong balls though. Not had any experience with them

Neither have I but I was reading the great info posted by KR2_Diving here: viewtopic.php?f=18&t=803&hilit=ping+pong&start=90#p9968 and it seemed that they could be an easy way to go.

[subn00b]

The project is still moving along with all the electronics now prototyped. The programming is basically finished but I need to finish programming some extra OSD overlay stuff.
Hardware wise, I've got all the motors, ESCs, props, batteries, and cabling and I just need to finish soldering connectors on everything and construct a power distribution board. Plus my BlueRobotics 4" enclosure is in the mail!

Here is a rough schematic for the electronics just to help me keep track of everything. The Controller module is in the top left, the Float is top right, and the Sub is down the bottom. Obviously the ESCs and motors aren't shown here but they all plug into the red PWM shield.
The OSD module is this: http://www.hobbytronics.co.uk/max7456-o ... rd=max7456
The IMU is this: https://www.robotgear.com.au/Product.as ... ement-Unit
The DHT is this: http://www.seeedstudio.com/wiki/Grove-_ ... ity_Sensor
The 5.8ghz tx is this: http://www.hobbyking.com/hobbyking/stor ... oCUafw_wcB

You can find a higher resolution version of the schematic here: https://www.flickr.com/photos/hughca/23 ... 5/sizes/o/

[SSN626B]

@subn00b,
I built my ROV Chassis out of 1/2" thick HDPE with 6 T100 Thrusters and two 4" diameter 11 3/4" long WTCs and I still had to add almost 5 pounds of ballast to get it to be just slightly awash.
Regards,
SSN626B/TCIII

[subn00b]

@subn00b,
I built my ROV Chassis out of 1/2" thick HDPE with 6 T100 Thrusters and two 4" diameter 11 3/4" long WTCs and I still had to add almost 5 pounds of ballast to get it to be just slightly awash.
Regards,
SSN626B/TCIII

Thanks for the info. I was worried about having to add a lot of buoyancy but it doesn't sound like that will be a problem!
Also I think I'm going to build the frame from 6mm thick acrylic instead of the HDPE as I'm thinking I'll just get it laser cut rather than do it myself.