This was just something I mocked up as a drivetrain base we could use for any contracts we receive by sponsorships. This one has the colors for the Tampa Bay Rays. Any changes that should be made? The large amount of 80/20 was to allow anything to be attached to it as a manipulator for whatever we would have to design
-6 wheel drive system
-2 AM 8" Performance wheels
-4 AM 8" Omni Wheels
-36" 1/4" thick Aluminum side plates. 5"wide
-Direct drive to the center wheels
I didn’t want to leave it solid. It will be covered by bumpers and the perimeter will be lined with .5" square tubing. The looks of it won’t matter, and in my opinion pockets make it look pretty neat. But that’s besides the point…
I do agree that the holes for the wheels need more beef. It is .5" width now, I should have put it as .75" width. The rest of it is identical to the plate we used for our 2009 bot. Its just a foot longer.
You plan on using 25-series chain to drive the omnis…how will you tension the chains? Also make sure the alignment between each pair of sprockets is acurate.
With 8" wheels and a 5"-wide plate (assuming wheel centers are in the center of the plate–at least it looks that way) gives you a 1.5" ground clearance? Should be OK.
I have to agree with others that you need more meat on the side plates…1" on the webs at least, and big radii in the corners of the pockets. Always start with a strong base, even if it’s not for competition.
80/20 is good stuff, but you have to watch that the bolts holding the frame together don’t come loose–they always seem to eventually. If you’re not going to take it apart, you may want to consider Lok-tite (or tack welds).
All that said, it looks like a solid, simple design that should go together very quickly.
I would be concerned with the front and rear driven omni-wheels. In our experience, having no side-force resistance to turning will lead to a robot that is very difficult to accelerate in a straight line.
We’ve used that drivetrain in 2007 and 2008. 2007 we used 4 banebot KOP gearboxes. 2008 we used an AM supershifter. Both years we had no problem with the robot driving straight. Even in autonomous with a little help from a gyro, we were able to drive straight.
I was considering adding those tensioners that Andymark sells for #35 but purchase them from McMaster for #25. But now I’m going to just cut slots into the plates and have an idler sprocket with a shoulder bolt. That’s always worked for us in the past. And lok-tite is a definate for everything we use
I agree with that. It’s not a lot of weight, and I’m going to put the aluminum one back on. Should look nice too. Thanks for the tip!
I’m assuming that there would be cheerleaders and people who cannot lift as much as we can. With safety in mind, I want to keep the actual weight of the robot between 120-150lbs. That includes bumpers around the perimeter, 2 batteries, and the rest of the robot. With this 30lb drivetrain, assuming bumpers are at a max of 18lbs like FIRST. There is approx 45-75lbs for electronics, and the manipulator.
Yeah! there are 5 up there. 2006-2009 are very durable tank drive drivetrain systems. They’ve been through pretty harsh competitions, and worse yet, off-season, and they’ve lasted through that. If you have any questions about any of those designs i’ll be more than happy to help. PM me or email me.
I’ll try to post more drivetrains on the team hosting website. I have a few on here, along with our T Shirt Shooting Robot the Screamin’ Eagle! I just need to finish up some work on it.