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Thursday, December 25, 2008

Christmas mutterings part 2

Well, the new battery seems to work much better but there are still unexplained things affecting the droid's performance.

This morning I moved my truck to the other side of the driveway to test the droid on a "clean" patch of driveway. The other side was all scuffed up from the tires. I wanted to see if and what was scuffing the driveway. In the test this morning, there are now a zillion tire marks (some up to 18" long) on the driveway. This means one of the tires (I think the right one) is dragging under certain conditions. I have no clue what that could be. Possibly motors not mounted exactly parallel? Or maybe a bad motor? Or a speed controller/transmitter that's not calibrated correctly? Or ?????? If anyone has any clues, please let me know. I'm pretty much baffled as I sit here. I thought the old scuff marks were from the old front center caster dragging. Not so.

It's never ending droid madness around here. The to-do's multiply exponentially. I will be glad to finally finish this project. After that absolutely no more robot building for me. I'll improve the bots I have but R2 is the last of the line.

3 comments:

Calvin Thomas said...

Are you sure 1 of the tires are not spinning out slipping alittle?
Doug mentioned something about certain motors not running at the same speed if 1 is actually running in reverse.
Not sure what that could be.
Calvin

Mike D. said...

If that switch is getting hot, then it's a point of resistance or an indicator that something is pulling more amps then the switch is rated for.

Even after you've wired directly around the switch, whatever was causing the high amp draw is still present; unless of course the old switch was bad. Maybe you should do a post-mortem on that switch and see if it's damaged inside.

Could there be an alignment issue with the drive wheels under load? Whenever you've got something running on extensions that far from the centerline, alignment is likely to become an issue that could present itself through motor mount flexing, or general slack between assemblies.

Jim Quinlan said...

Thanks for the tips guys. I'm leaning toward alignment issues and plan on tearing down the droid and re-aligning the motor mounts after a lot of measurements. I may need to make the slots in the ankles a little wider.