4329's Drive Train
 

We received our painted frame and belly pan back last night and went about assembling our all gear drive (minus the gearboxes) -





Once we get our 3 CIM ball shifters in and get everything wired up I'll post a few more pictures.

The frame, wheels, gears & hardware are under 20 lbs. The frame is made from .090" 6061 T6 Aluminum. The center 3 wheels have a .100" drop from the outer wheels.

A big thanks to our sponsor Seyer Industries for making this possible. Also thanks to teams who have posted their inspirational all-gear driven designs in the past, I don't think we'll ever go back to chain or belts now.

Feel free to ask questions, thanks!

Re: 4329's Drive Train
 

So hexy <3

Re: 4329's Drive Train
 

Under 20 for full gear drive. That's spectacular.

Re: 4329's Drive Train
 

Without the gearboxes & CIM motors :) Once we get those the weight will easily double.

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Tonight we got our 3 CIM ball shifters incorporated, the drive is mechanically complete awaiting controls and wiring:

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And I thought our direct driven mecanum with sonic shifters was cool...

This is the most gorgeous drivetrain I've ever seen. :D

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I cant see the pictures because my school blocks them :( But, I did see that your chassis weighed 20 lbs with hardware. That is very light! Now I cant see it, so help me out here. Did you guys bend your 6061 aluminum? We had a couple things bent out (like a battery box, and a claw for 2011) and our battery box was really weak at the bends. In fact, one match, we got a hard hit and the box cracked and we had to replace it.


Our chassis is water jetted 5052 aluminum. We got this idea from team 67's 2012 tech notes (Which I recommend everyone reads). We bought the stock 5052 sheet and gave it to Chrysler for water jetting since they only have 6061 stock.

Anyways, our frame is 10lbs without any wheels or gearboxes. We are getting it powder coated and we will put them on. Our prototype shooter weighs more than the whole chassis!

Edit: I saw the chassis! It looks really nice! You sure use a lot of rivets! By the way, changing http:// to https:// in almost any link that is blocked will let you go to that site

Re: 4329's Drive Train
 

Our sponsor did bend the 6061 T6 for us. We went with a larger bend radius hopefully to avoid cracking or fractures. This is our first year trying a sheet metal drive and our first year doing all-gear so I'm sure we'll learn a few things that we should or shouldn't have done for next year.

One other feature that I'm loving (so far) is that we don't have a flange on the bottom of the outside plate. This allows for very easy removal & insertion of our wheel assemblies. Our tube shafts are low enough in the frame that they act as support ribs. We're still considering adding additional standoff supports if needed once we start driving this with full weight.

Re: 4329's Drive Train
 

Beautiful drivetrain! 1983 accidentally cut some 1/16th 6061 on the waterjet in the pre-season and decided to try it rather than scrap it. We found it bent quite well when we used a large radius tool, and didn't show any issues with cracking in the corners. I am surprised that your shop was set up to bend 6061, since most sheet metal places I've worked with heavily encourage 5052.

Regarding the flange, I suspect your shafts will be enough support considering you'll have bumpers on the chassis during competitions. The only scenario of concern would be a point load low on the side panel in between shafts, and that's going to be hard to do with a flat field and bumper-to-bumper contact.

Re: 4329's Drive Train
 

We routinely bend 6061 in house as well, and just use larger bend radii to avoid cracking.

Re: 4329's Drive Train
 

Evan,

6061 sheet stock comes in different tempers. T0 to T6. The T0 temper will bend easily. Heat treating after the bending process to get the part strong and stress free.

The T6 temper will crack if the radius is sharp. Another way to bend 6061 T6 is with a wrapper. The wrapper will make a large radius using sharp 1/32 inch dies.

Re: 4329's Drive Train
 

We did a weight check tonight with everything we could think of that will be on the fully assembled robot. We may need to add weight :]

Re: 4329's Drive Train
 

30 pounds of LEDs?

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Very impressive, look forward to seeing you in STL! Would you mind explaining how 10wd drive works? I would assume one of two ways.
1) Drop center and outer two are at same level
2) Wheels form an arc where the middle wheel is the lowest and the outer wheels are the highest.

extremely impressive either way :)

Re: 4329's Drive Train
 

We went with the 3 middle wheels being dropped more than the outer wheels. I actually hadn't even heard of this wheel arcing until 703's thread came up again so we'll have to look at that for the off-season or next year.

Oh there will be LEDs :)

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I would imagine that would have issues turning. Essentially a 6wd without dropped wheels and all wheels are high traction.

Re: 4329's Drive Train
 

The distance from wheel to wheel is fairly short reducing the need to have a single wheel be the only wheel that is dropped in our drive train. I'd highly recommend reading Chris Hibner's white paper on drive trains for the theory behind this - http://www.chiefdelphi.com/media/papers/1443

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Perhaps we'll have to compare notes after the season is over. :rolleyes:

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Bungies? Where we're going we don't need bungies.

Anyone else giving the Vulcan springs a shot this year? We like them quite a bit.

Re: 4329's Drive Train
 

That is a beautiful chassis, nice work!:D

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Thanks! You guys always put out some great looking robots as well.

We got our robot fully assembled last night and did an intake test for getting the ball onto our catapult - http://youtu.be/4_dxwPukRPk Things are a little tighter than I'd like at the moment but it's good to know everything seems to work with each other.

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We had Vulcan donate springs to our team last year and will be using a few again this year. We were only using 6lb springs though. How big are the ones you are using, 40lbs?

Also have you done any traction tests with the VersaWheel DTs? With the little bit we have done, they seem a lot worse than the old VersaWheels.

Re: 4329's Drive Train
 

We are using four of the 40 pound Vulcan springs currently. We found out if you put a 2.875" BaneBots wheel inside of them it makes for a really easy mounting solution.

We haven't done any traction tests yet. Unfortunately we don't have enough carpet to really do a full run but we should have that chance this Saturday. The nice thing is we have a bunch of the old VersaWheels so if we need to make the switch it should be a pretty quick swap.