Robbe Seawolf V2

I have been making a dsrv for the back of the sub, it's a rough first draft.

I had the sub out for its maiden voyage at the Largs model boat club open day and things didn't quite go to plan, I forgot to connect the control rod to the front planes, and I managed to pull a tube off one of the pumps, so when I tried to dive the water sloshed forward and hit the receiver and I lost RC, I had also forgotten to set the failsafe again as I had rebound the receiver while troubleshooting forgetting that it also reset the failsafe. So when it lost signal I was trying to dive the sub, so it ended up doing circles scraping along the bottom of the pond and I had to wade in to get it.

The reason I like the Largs pond is that the bottom is smooth, and it's only up to my knees, so there was no chance of losing the sub if things went wrong.

I didn't want to click "Like". if you see what I mean!

Heck, we have all been there. Why is everything underwater so difficult?

It will all be better next time. Stick with it.

Lovely pond, by the way.

David

I have plenty of plans for this sub, I am going to put the 2 water proof servos in the front along with a water jet bow thruster, camera in the mast, and some more work on the flight controller dive system. Its been tested in the bath again since it failed at the pond and its all working fine. I plan on doing that once the dark nights start, as I'm currently working on my solar rover.


I have been writing code to convert robot vacuum cleaner lidar scanners for use with mavlink protocol, so it can be used with flight controllers along with some other experimental radar and AI camera systems. it's a bit of a time crunch to get it working as the dark wet nights are coming. its basically made from 3 reprogrammed hoverboards with 3d printed tyres bolted to a plastic crate. It's a test bed for the electronics that are for a long range autonomous boat as it's much easier to get it all tested on land before I put it in the water.




https://www.youtube.com/watch?v=qBKi5ORgOj8

quote again lol

I have rebuilt the sub after its last trip out to the bottom of largs pond, hopefully to stop it happening again i have implimented a few fixes:

1. I have secured all tubes inside the sub, the main reason it sank was that one of the tubes got snagged by the WTC as i was closing up the sub, this pulled the tube off the pump causing it to fill the wtc instead of the bladder. so now it shouldnt snag when closing up the sub.

2, I have replaced the peristaltic main ballast pump with a geared pump, its just much faster to dive and surface, even overvolting the other pump took minutes to go under. https://www.ebay.co.uk/itm/353689843234

3, the flight controller has been totally reprogrammed with custom mixing so i can static dive while keeping the sub level.

4, failsafes have been set so it will blow the ballast if rc signal is lost.

5, I have connected the sub trim pump to the gimbal output so it will try and keep it level without using the pitch output.

once im sure it will work reliably then I will look at upgrades.  fpv camera, bow thruster, pressure sensor for inav and depth sounder.

I have the thruster and sonar to install, now that I have the software functioning I can finally get around to cutting holes. I am still not sure where I'm going to install the thruster, I would like it at the front but routing the wiring would become very difficult, fitting it at the back would be simpler but it would be less effective. The sonar will get installed on the rear of the sub at the bottom, there isn't really anywhere else it can go.

I have been giving the sub more thought on how to manage its ballast. So currently it has a main ballast bladder ran with a geared pump and a trim ballast bladder with a tiny 5v peristaltic pump at the back of the WTC for levelling the sub. The main ballast can be manually controlled but it's eventually going to be controlled using external water pressure for depth control and the trim pump can be manually controlled, but I'm going to connect it into the inav stabilised output using logic switches so it can trim the sub automatically.

After its issue last time when i couldn't get it to resurface, I have been thinking of adding an emergency ballast system, basically there is some free space outside the WTC at either end of the sub so I'm thinking I could add a bladder at each end that I can fill with air from the main WTC if it has issues with the main ballast.

I got the sub out today to see what it needed for the summer. I'm going to forget about the pumps the next time out and just get some time on the water before trying to dive.

I also left the 3s li-ion connected, and even tho it had a BMS it was totally dead when I plugged it into the charger so that will need replaced too.

Pumps, and ballast need some work, the trim pump isn't moving and I'm still looking at the barometer depth hold, so I'm just going to try dynamic diving next time I try to dive it.

When trying to cut a cable tie I managed to nick the boot for the rudder connecting rod, and trying to find large enough boots wasn't easy, I ended up having to modify one to make it fit.

To top it all off I stripped the thread on the bolt that holds the sub together, replacing that is going to be interesting as its in very securely. To be fair it was well-worn already, there was a smooth section on it when I got it so probably half the thread was gripping.


So a few issues before I can take it out again.