I like all of those ideas, definitely want to build a new test rig, make some new tires and revisit this one

The torque is definitely high enough to loose grip, all of these do (mostly because there is not enough weight in the robot)

I took a small break and KZfaq is trash at notifying people of videos

Theres a good chance the 30:1s spin the tires at the start. Yes, kind of, its showing at what point the traction breaks at least with the current set up. I need to refine the test some I'd be interested in trying 20 and 15 to 1 but they arnt as common so I dont have any to hand. I'd need to find some online to order in

Sorry to butt in, guys... 🙂 I was just thinking that the high torque achieved by mega-gearing wouldn't really be usable with such small and nippy bots. The force created would be high, but the speed of actuation would be so slow that whatever you were trying to lift or crush would have zoomed out of the way long before the geared-down weapon could engage it. A fast-acting servo is probably a better bet in this weight class.

Yes the gearboxes are screwed on, but unfortunately no they are not interchangeable at least not all of them. I've tried in the past, but the pinion gear on the output of the motor is a different size for the different gearboxes If you got lucky and found a high ratio box that used the same pinion gear as one of the dfrobots ones, then it would be fairly powerful. If you found one that matched to the exact speed of a 9g servo, it would probably be a little heavier then the servo, as the servo uses a smaller motor size and plastic casing for the gear box rather then brass. But then again maybe not, the servo does also need the position sensor... hmmmm... might be one to look into later

Yes! There is a club in Melbourne, they have held a bunch of events in the past, but have been struggling to have events due to covid, but they are doing what they can, including virtual build nights You can find them on FB: facebook.com/groups/melbournecombatrobotics

It depends on the receiver you are using, some can run on the full 2s lipo voltage, in which case you just plug the dfrobot motors in If your receiver runs on 5v you will need an external bec and to run power from the switch straight into the motors, this is a lot more work and i highly encourage you to get a receiver that can run on 2s voltage like this one: kzfaq.info/get/bejne/pNakZ91ptZmnlY0.html

fully charged 2s lipos (charged between each test) so 8.4v

6v or 12v ratings on these motors are meaningless. As far as I can tell the motors are built exactly the same, and the "rated voltage" is just the voltage that they tested the speed at. I've bought some n20s labelled as 3v motors, ran them on 2s and noticed no difference in them at all I run all n20s I own on 2s because all of my ants run on 2s If I get the improved test set up working reliably, I will be doing a bunch of testing including if tyre tread impacts grip (personally I use treads rather then slicks because my first experiment with them I used both, and found the treads had a little more grip, I think because the tread helps clear some of the dust/dead robot junk out)

Haha I've done that once, My problem was that if the robot is hit while spinning 10:1 gearboxes tend to break, which is not fun

50:1 but watch the video because in all things like this there are compromises at each gear ratio and what someone else thinks is worth trading up for to lose something else, your needs might be different.

Ooooff yeah those are super slow