RC Tank Warfare community hobby forum

ok, as promised, here is a thread to hopefully track the progress of my crazy project - please feel free to ask any questions or offer any constructive criticism

Its probably worth pointing out that while I have a background in electronics, technology and software development, a lot of the aspects to this model involve quite a learning curve for me - which is exactly what I wanted from this! I have been searching around for quite some time for a chunky hobby to keep my brain active and allow me to lean new things and this seems to tick just about all of my boxes

I started of by pulling a rough and ready block diagram together that would be about the size I was aiming for so I could get an idea on the relative ratios of the various components and sanity check that I could fit all the bits inside that I wanted to (more on that in a bit)

This was also my first attempt at using Blender so be gentle with me
As this was primarily a vehicle (pardon the pun) for me to learn loads with, some may argue that it has more going on that your 'standard' model but this is by design

Planned design features include:

* Two rotating hubs/turrets
* Primary weapon with elevation and recoil action on forward hub
* Independent secondary weapons with elevation and recoil on forward hub
* Independent missile pods with elevation and recoil on rear hub
* Movable and rotating miniguns on secondary hub
* Robotic arm on secondary hub with at least 6 degrees of freedom (these things are tricky!)
* Lots of lighting! (big fan of mood / effect lighting as anyone who has visited my house would agree with LOL). These include:
* Addressable RDB LED strips inside the three air intakes (aiming for a turbine effect that will spin faster the quicker the tank moves)
* Addressable RDB LED strips inside primary/secondary weapons (think rail gun effect when firing)
* Addressable TGB legs inside missile tubes for firing effects
* Four real time cameras (front, rear, forward turret and end of robot arm)
* Three independent cooling zones (I understand brushless motors and LiPos can get quite warm under load )
* System control and operation is via a number of Raspberry Pi boards
* User control is via a combination of a PS4 controller and another raspberry Pi with 7" touch screen - this will allow you to display a feed from any of the four cameras (or it's it own camera) and select weapons systems, special effect, etc)
* I am also looking at AI based object recognition and tracking and Augmented Reality to allow the physical model to interact with other physical models and virtual models in a 'game world' - its really quite amazing what you can do, even on a humble Pi!

This is a more detailed design of the main body - it is comprised of 7 main rings, each ring having 6 segments that are bolted together. There will be 10mm steel rods running the length of the body to try and give it some rigidity and stop the drive motors form twisting it apart

The wheel pods are still work in progress (much like the rest of it actually) but this is what I have so far: there a 6 of these in total, three down each side. All three are driven from the same motor so shouldn't get out of synch with each other. I have found some very cool springs on eBay that come from a rock crawler which should smooth the ride - 8 of them per wheel pod. These should also help keep the track under some tension so it doesn't slip too much


This is a single track segment - going to need quite a few of these as there are two sets of tracks per wheel pod - I am under no illusion how long this project will take or what it will cost! The wife, however, may be a little in the dark on the latter....

Got some additional lighting on the front which can be switched on in various combinations…. two on each forward wheel hub and two on the body
I am still researching DC motors and motor controllers for the various moving parts. For servos I have settled on the Hitec HS422's (for now)

The nice think about using the Pi boards is I have almost total control over any sort of signal I need to read or provide within the model which allows for some creative thinking

Locomotion is from a pair of Hobbywing XR8-Plus 150A ESC's With 4274SD G2 2250kv Motor
Powerplant is a pair of 16000mAh 6S 22.2V 30C LiPo Battery - Overlander SupersportXL

I am considering a third slightly smaller lipo to power the onboard electronics an, lights, smaller motors, etc - still undecided here


Finally (for now), here is the electronic brain that will be managing this crazy idea of mine.... can do quite a lot with a total 16 cores and 4gb of ram
I will do my best to keep this thread updated with ongoing successes and failures as this little adventure unfolds. Like I said, I am still learning so please go easy on the comments but if you can think of any improvements, alternative approaches, etc, I would love to hear from you

Thanks for your time guys and gals

Paul

Hi Paul, what can I say, WOW , this looks like it's going to be quite a large beast and I totally admire your vision. My worry on this is the vehicles ability to turn/rotate in place as there will be huge stress on the drive pods plus with one motor per side of the vehicle, you will need some very clever gearbox/drive system. One solution to that could be stepper motor drive belts which you may want to consider.

I will be watching and following on this with very great interest.

Alwyn

AlwynTurner wrote:Hi Paul, what can I say, WOW , this looks like it's going to be quite a large beast and I totally admire your vision. My worry on this is the vehicles ability to turn/rotate in place as there will be huge stress on the drive pods plus with one motor per side of the vehicle, you will need some very clever gearbox/drive system. One solution to that could be stepper motor drive belts which you may want to consider.

I will be watching and following on this with very great interest.

Alwyn

Yeah, go big or go home, right? As I am doing this at home, I have no choice but to go big! LOL

This is the current design but I need to rework to provide a 15:1 step down using some steel gears I have just ordered - I suspect I may need something a little stronger than PLA for some of the 3D printed components too - its on my list to research. I have a Prusa i3 Mk3 which can print in all sorts of materials but I have not got round to testing them yet Is there any benefit to using belts/chains to transfer power over a driveshaft as I have above? I guess it saves power losses through the bevel gears...?
The 10mm steel rods running the length of the body should hopefully alleviate the lateral stress through turning but I will defo be mindful of it, thanks

after taking on board all the comments from you lovely people, (and cramming a few courses on Blender to get my head round making it do what I want, we now have a version 2.0 of the hull

I have to say, I am quite pleased with how much cleaner and more accurately this has gone together... using chain drive rather that prop shafts was 100% the way to go!! please forgive the bold colour coding - I find it more useful that everything being battleship grey...

Dark blue = LiPos
Green = ESC's
Red = drive motors
Yellow = steel gears
Purple = roller bearings
Orange = Pi cluster

this also has the advantage of a nice open internal spends it self to having some internal modelling at some stage - is it wrong to put windows in a tank so you can see inside? LOL!

Still very much a work in progress so please keep the comments and suggestions coming - for scale, one floor tile is 180x180x4mm

thanks for all the support and encouragement - you guys are awesome!

Cheers

AD

Spent the last few days playing with a new slicer - much happier with the results!

One half of a drive wheel and some track segments designed and draft printed
Also done some size tests to make sure the voids for various rods and bearings all fit properly (which they now do after the 3rd attempt! )