would love to see a blog post or a build thread on your RTK set up, very interesting.
Yes, either a chassis like that or a 4 wheel steer crawler. Of course the crawler would still have a turning radius just tighter.
I’m looking into purchasing this:
Wild Thumper 4WD. This says it doesn’t come with the wheel encoders. As you know my current setup is running from the pix to the ESC of the rover. Will I need anything else to buy to get this working with the pix?
Are wheel encoders required to run between the motors of the wild thumper & the pixhawk?
Just found this. Looks complicated. Do I need to buy all these parts to get it working with the pix?
No, but you will need ESC’s . You could use one of those 2 channel controllers or use 2 ESC’s similar to what you have now in your truck. Hobbywing makes decent ones, I used one in my previous truck . You don’t need wheel encoders but it might be useful if you could add them. They can supplement GPS for positional estimation. I don’t have experience with this but have read some accounts on here and there is a Wiki entry.
Hey Mus-I finally got out today for a thorough tuning session and after going through Throttle, Steering and Navigation the performance improvement was dramatic. I’m not suggesting you copy these parameters and some of them are very vehicle specific anyway but I would be interested to see what you have with a vehicle similar in some respects. The 4 point Mission I was doing to tune L1 was almost spot on the Waypoints even after repeating the mission ~8 times at up to 3m/s.
Note: The Turn G max value was determined when the vehicle rolled over while steadily increasing the throttle driving in a circle. That was fun…
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That’s great news Dave glad to hear your rover is performing better with the new settings.
my rover is doing well but sometimes the EKF is going in the red and im getting bad AHRS sometimes. anyway to fix this?
Also I found another small rover on amazon. Wanted to hear your thoughts on it. Looks pretty basic but similar size to the wild thumper and much cheaper:
Engine Specs:
Power Supply Battery: 3.7v 18650 * 3 (NOT included)
Voltage: 12V DC
RPM (Revolutions Per Minute): 320 rpm
Diameter: 25 mm
Shaft length: 9.5 mm
Weight: 180g
Maximum effective point: load 4.0kg.com/235rpm/2.5W/0.58A
Stable current: 4.8A
Current: 0.55A
Height (without shaft): 68mm
Shaft diameter: 4mm
Torque: 7kg.cm
Max power: load 7kg.cm/215rpm/3.1W/0.65A
Also not sure about which motor controller to purchase that’s suitable for the rover and what would work best with the pix.
Bad AHRS means it’s not happy with the position estimate. This can happen on start-up if it doesn’t have good GPS position info yet. If that’s the case and it goes away after a minute or so it’s no problem. I don’t think it’s related to the compass but you do only have one enabled right?
I think you will get what you pay for with that vehicle. It looks Toy grade to me. How fast do you plan on running the vehicle during a typical mission?
Yeah your right it does go away after a bit of time but during driving it manually when I turn left or right all the way like doing a doughnut it then comes back up,
Yes it is toy grade lol it’s says it can go 320rpm but I’m not looking to take it past 0.5 m/s
All those chassis including the Wild Thumpers use 25D brushed gear motors with 6 or 12V rating. The wheels are fixed to the gearbox output d-shaft with a set screw. So all the forces that occure during driving/turning are taken by a brass sleeve bearing and a small pin on the opposite end of the output shaft. The brass bearing and/or the pin wear down quickly, especially if the rover is heavy. The brushed motors also tend to fry if they stall for to long. And replacement motors are surprisingly expensive.
Rather than going for what I’m thinking of what would you suggest would be a better option for me? Thank you
I just wanted you to know what to expect.
There are some robot chassis that use bigger 37D motors with gearboxes and they have 6mm output shafts instead of 4mm, but I never used them, so I can not tell you anything about the quality.
Lynxmotion A4WD2 and A6WD2 use 37D motors for example, but they are not cheap.
yes ive seen these they look really good. around £200. but on the youtube videos they really sound loud, and I mean loud. that’s why I thought id continue looking for other options, but yes they are in my sights on what to purchase
There are a lot of gears turning, that will never be silent😁.
What makes this Aion robotics rover better than the Lynxmition?
If I go for the Lynxmotion what kind of controller will I need? Is the Sabertooth dual 25a an overkill for this or could I use something less expensive?
As I mentioned you could use Brushed ESC’s for RC Cars/Trucks similar to what’s in your current truck. 2 of these dual units from Hobbywing would work:
I was thinking of buying a duplicate ESC to the one I’ve got like you mentioned & somehow modding my current rover to operate like a skid steer. The suspension on this rock crawler is amazing & can handle going over pretty much anything whilst maintaining a straight path.
Not sure if that’s possible tho unless I attach 4 motors to where the wheels are
Impractical to attempt a mod like that on that chassis. If you don’t really need zero turn look at the 4 wheel steer vehicle options. In fact I was looking around for a 4 wheel steer kit for my vehicle. There are some but not for the model I have.
It’s a good point about the suspension on these trucks. The suspension on most of those skid steer chassis are the tires… Ground clearance is a consideration also. At least for me it was. My previous Basher chassis Rover had much less than this one and would bog down in tall grass. I even stripped a wheel hex drive that way once. I happily sold that truck to a nice guy that bought it for parts for his sons truck.
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I used a Sabertooth 12A in my wildthumper 6wd and never came close to its limit. A 4WD rover even with 37D motors should be no problem.
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