One of the problems I can’t stop thinking about is how we are going to steer that airship. It is easy to do steering like we are doing it today – when we have just two motors and two vectored thrusters, but how’s that all going to look like with that plus 4 more gimbals? To see it all working I came with an idea of a test rig which would allow us to develop a control mechanics and test those easily.
It took a while to come from an idea to practicalities, but I’ve been finally able to explain all what I am looking for to Serge and we came with a plan:
I understand that it looks bit wild now, but what you are looking at is our future testing rig. Just imagine a frame wider than our cart which surrounds it with multiple weight sensors on all sides. It also comes with a facility to balance whole cart in the air so all values the reads from sensors are not biased with any friction coming from wheels. Finally whole system is completely stationary and shouldn’t move at all so there is no need to reset it. Also whole system to be fed by that 2kW PSU (24V, up to 81A) which arrived couple weeks ago to mitigate any power fluctuations from batteries.
After agreeing with the plan with Serge, we went shopping – to local Bunnings store. It was cheaper than what I initially thought of.
Surprisingly we didn’t start with the frame, but with the PSU. Serge quickly mounted power plug and I did bit of soldering with XT-90 to fit our power bridge. Multi-tool confirmed that have it all right – 24.17V. Same voltage came at the end of that 5m 2.5mm copper twin cable, what was quite relief as I was bit worried about some decline there.
Let’s see how is all that going to perform when feeding 6 motors on a full power. A screenshot from calculator below shows that it shouldn’t necessarily burn out.
Well, than it was lots of measuring, cutting and screwing – unfortunately we were so efficient that I forgot to take pictures. I took few afterwards. The first one gives a good overview on what we achieved. There firm frame with posts and rubber bands.
The same, but upside down – showing glued triangles to provide some structural stability and adjustable legs.
Finally with our cart fitted in it.
A detail of the rubber band hanging from the post and lifting our cart.
Now couple more pictures to provide better perspective on how it looks.
You can notice that those rubber bands are not holding it exactly in a center of that rig. I am still working on that, but whole system is perfectly sensitive and responding nicely to all external influences. Sebi demonstrates on video below.
Watching that video above again I also think that all that cart should be hanging higher, but that’s again something to solve whilst we’ll be mounting sensors.
Finally Sebi wanted to see how it all works with engines, unfortunately our right engine and both vectors are currently under service (undertaking a planned upgrade 😉 ) so we had just the left one to go with. Anyway I was curious as well as that will be also premiere for our new super-beefy PSU.
I think it’s awesome! There is a clear and demonstrable push / pull from that motor on a whole system and I can’t wait to see all that being measured with our load sensors. 🙂
We’ve progressed with Sebi on those through the day and did much more, but as we haven’t finished I’ll keep it for another post.
Huge thanks to Serge and Sebi for helping me for a whole weekend and I hope you all enjoyed seeing some serious progress we are doing lately. As always feel free to post any comments and ideas, those are always welcome and provide us with motivation to keep going. 😉