Homebuilt ROVs Forum

First time in the water for the new frame design needs a few tweaks but not a bad test run

Could you talk a bit about the previous 3 frame designs and what makes this design better than previous designs?

I LIKE IT!!!!


Keep up the good work

What thrusters are you using and voltage?

Thanks for the comments.
I'll post pics of the other frames under My Meager Machine post, oldest frame to newest.
1st frame was to big and bulky for the motors I'm using, I modeled this frame after the Hornet http://my.fit.edu/~swood/ROV_2.html. The motors are ducted fans from Tower Hobbies http://www3.towerhobbies.com/cgi-bin/wt ... LXSBF7&P=7.
These motors were cheap and had the duct and blades all ready to go just had to built a motor mount. The bilge pumps around here all seemed to be kind of expensive and I didn't really know where to start with picking the right props. More blades means less cavitation as well and these fans have 6 blades. If the motors go out I can always put brushless motors in fairly easily.
The ducted fans have brushed motors running right in the water. No problems at all. I run them each for a min or two to dry them when the dive is done to prevent corroding. RC hobbyists run these brushed motors in water to break them in.
I'm running 12v down 100' tether and getting around 5v voltage drop. The motors can run up to around 10v.
2nd frame was to hard to balance. It wanted to flip upside down and it seemed like no matter where I put weight I couldn't make it right, Not to mention control was something of a joke.
3rd frame was better but the cup I was using didn't allow room for the dive motor to be mounted in the middle of the ROV, so the ROV would tip up and down and not dive level. And the cup was just a plastic water bottle which couldn't handle any real depth. I dropped it down to 82' and when i brought it up
4th (this design) has a mirror quality to it. The back cup with relays in it (toilet floor drain 2" abs plastic pipe, cap, lexan window, and riser ring that matches the drain) Then the dive motor then the front cup, same as above with camera in it. Control, balance, and weight are much easier to manipulate and tweak.
I am in the process of redoing the lights. This is the fourth time for the lights as well. Between voltage drop and leaking enclosures the lights have also been a big challenge. I'm putting the lights on their own battery power so no dimming with voltage drop. They are cheap Harbor Freight 9 led flashlights
($2.50 for 2) hacked and stuffed into a slip pvc coupling 3/4" and 1 1/4" cap on the end. They fit perfectly with an O ring and the rubber grommet inside the coupling and a lexan window. Sickaflex sealing the wire entries. I'm feeling pretty confident in this setup.
Trying to find the right combination of thrust, mass, weight, buoyancy, balance and power is the real trick I think.
Deakel

What I did for balance was go to harbor freight and buy 4 of those cheap postal scales. I used the scales in all 4 corners and added or took away weight to get the rover balanced.

Good Idea on the thrusters!

Yea I bought one of those cheap scales from harbor freight myself. I have been using (pencil lead) fishing weight it comes on a small spool and just unrolls. I found this to be the best cause I can fine tune the weight and put around the pvc anywhere on the frame in small rings.
Thanks though
This one seems to be the ticket I just need to get to the lake to do a real test. I might even be able to capture a wiper boil on camera. I would love to see an underwater view of that.
Deakel

Deakel wrote:... I might even be able to capture a wiper boil on camera. I would love to see an underwater view of that.
Deakel

What's a wiper boil?

A wiper is a cross between a white bass and a striped bass average 4 to 5 lbs and fight like crazy. They hit your lure and run and run. They work in groups and school up shad then have a feeding frenzy the shad come up out of the water trying to get away from them. It makes the water look like its boiling. If you can get in a boil and cast lures into it the fishing can be pretty wild and fast. It's a ball. They pretty much only boil in the late summer when its still hot. I'm not sure if I can get the ROV in position or not It may take a couple of tries meaning maybe a couple of years or seasons. They can be skidish and boils dont always happen near you or for very long. But I've heard of em lasting 20 to 40 min at a time.
Lot of fun chasing em though.
Deakel

Stripped bass, shad, we are talking about salt water then? (I am a trout fisherman on the West Coast, forgive my ignorance!)

Fresh water fish in northern Utah I don't know very much about ocean fish.