No real physical progress, but lots on the design side of things.
It'll just be a matter of raising the funds to get the designs manufactured in 2013 I suppose, we'll see :)
I've just added RS485 to my thruster PCB as I think that a multidrop network on the ROV, when it eventually comes together, would probably be the way to go.
Here's a screenshot of the design so far, it's pretty tight on there and that's just one side of the PCB!
The large through hole DIP IC is a Microchip microcontroller to control the brushless DC motor in the thruster.
On the mechanical side of things, here's an image of the thruster as it stands currently.
I've created a new design for the Kort nozzle that I'm hoping to get 3D printed, depending on cost, then we'll see how it performs in the tank next year.
I've also been looking at the design of the actual ROV (in its very formative stages (see below)) with six thrusters, four horizontal and two vertical.
Putting six thrusters on the design really shows how complex a vectored open frame design can be, but the benefits I think will outweigh the complexity in the end, increased thrust and maneuverability to name but two. Although there's a slim possibility I may go for a three thrustered configuration initially to cut down on costs, we'll see.
OK that's it for 2012, I hope everybody has a great Christmas and New Year, and hopefully 2013 will see some of my ROV plans getting closer to fruition :>
Do your thrusters come with ESCs attached and your board is just sending PWM or are there ESCs on the board to control the motors? If the latter I might like to test/purchase one.
ReplyDeleteThe thrusters have a built in ESC, at the rear of the thruster, the 3D screenshot of the ESC printed circuit board is shown in this post. The PCB is designed to be pressure tolerant. The motors are brushless.
DeleteI've just re-designed the PCB to have a half duplex RS485 interface as well as the analog control and digital direction control, but it's yet to be tested.
I'll probably do a post with a block diagram showing the various components and interfaces of my envisaged design to make it a bit clearer, as most of it is in my head.
It's not really at the "selling point" at the moment, but if you want you can send me an e-mail at martinwarehamAThotmailDOTcoDOTuk to discuss your requirements/application further.
Hi there,
ReplyDeleteJust made my first SUB with three thruster motors but they were not very powerful 12v bilge pump motors. From you video I can see these brushless motors pump out quiet a bit of thrust. I am not so much into the electrical side of the build. So learning everyday. What motors are you using and what ESCs would you use of the self [i know you have integrated them]. Are you using magnetic coupler or is it a direct drive? Would love some advice. I am getting really stuck with what to get. i am just looking to make one new Sub for now. [infoATundercover-designDOTcom]
Thanks BJ
Hi BJ,
DeleteI have a good friend in Houston called BJ :)
Glad to hear you've at least got an ROV, I haven't got that far yet, just a thruster design :(
Having siad that it is a rather nice thruster design, even if I do say so myself :>
So yeah, the brushless motors are great, very fine control, even down to low RPM for those intricate underwater maneuvers and lots of powwer too!
The motors are from Anaheim Automation, 80W, 24VDC, not cheap but very robust, which is what you need when you're likely even with the best intention in the world, to get them covered in salt water at some point in their lifetime.
I don't really know of any off the shelf ESCs as my intention all along has been to design my own, in order to take advantage of the oil (pressure balanced design) and sea water heatsink, as most off the shelf ESCs don't take this into account.
Direct drive with a shaft seal at the front end of the thruster, which being pressure balanced means the seal doesn't get a big differential pressure across it and bind up on the shaft.
Feel free to drop me an e-mail if you would like to discuss your design further :>
Cheers,
Martin