Another new video 3/4/12. I got it all together and it WORKS. I think it did pretty good, many changes to come.
Added another video of me trying to pull myself on a snow sled, even though there isn't any snow :) it drained the battery at an alarming rate, I'm changing to 10:1 gear ratio and gonna have to increase voltage to maintain some speed. 5:1 gear ratio is fine if I don't want to pull anything, but I want it to have a little more grunt.
This is a work in progress ATM, my major obstacle is coming up with my own tracked driving system, including every aspect of the track drive system (except making the tracks, they are youth snowmobile tracks). I've been through several prototypes to get to the point now, and actually am changing the drive system again. It buckled under the track tensioning system, so i'm changing it again, actually going back to an older model with some new ideas.
Everything is geared to go 16mph, however I have no idea if i'ts really going to do this or not. I did have a unit assembled, and tested powering it downstairs, i think one track output about 40lbs of pushing force at stall. However I used my hand as a gauge, so 40lbs is just a guess. There will be 2 tracks, so double that power. Granted I don't know how this will translate to real world performance, but at least it has what seems to be a decent amount of power.
The gearbox I used can be switched out for many different ratios, 10:1, 20:1, 40:1, 50:1, and 60:1 are available, so if the rest of the design works, changing gear ratios won't be that big of a deal, and overall won't be that costly either. I have a feeling i may have to goto 10:1 (cutting my speed in half) to get the power I really want.
Here is a shot of the internal track drive system:
Top mockup view:
Runs over stuff, should be very snow capable, as well as most other land terrains.
- Actuators / output devices: NPC Black Motors with a 5:1 gearbox to a 10 inch wheel.
- Control method: android phone/tablet via wifi
- CPU: Beagleboard XM
- Operating system: Linux
- Power source: 2x12v lead acid, possible conversion to lipo in future
- Programming language: C++
- Sensors / input devices: Current sensors, voltage sensors
- Target environment: outdoor ground
This is a companion discussion topic for the original entry at https://community.robotshop.com/robots/show/large-tracked-robot