Winnovation Midwest Coast Drive
 

Team 1625 Midwest Coast Drive
-6 Wheel West Coast Drive
-Completely belt driven using Gates GT2 Belts
-5mm GT2's in the frame
-3mm GT2's on the gearbox
-Gearbox contains AndyMark Gen 2 shifter gears and dog
-Custom CNC'd hex axle's
-Shortened body pancake cylinders for the shifters within the gearbox
-Single Bolt roller bearing tensioner on gearbox
-Cam based roller bearing in frame tensioners
-Wheels made of UHMW for cost purposes
-Built in encoder mounts
-Testing will be done soon

(Sorry it is a couple days late, and sorry for the resolution of the photo's)

Re: Winnovation Midwest Coast Drive
 

Carrington,

You Winnovation boys never cease to continue creating amazing things. It looks great!

-Katie

Re: Winnovation Midwest Coast Drive
 

Neat! With belts and only two total reductions it probably sounds pretty slick when driving around. Are the motors being used as a means of structural support between the two transmission plates? It looks like 'fun' to take apart and put back together.

Looks sleek. :)

Re: Winnovation Midwest Coast Drive
 

Wow, that is a very pretty robot! You guys never cease to amaze in the off season! How much does that beauty weigh?

:yikes:

Re: Winnovation Midwest Coast Drive
 

Yes. The motors are being used as structural support. It is actually relatively easy to take the gearbox apart.
As show in the picture this robot weighs 51 pounds.

Re: Winnovation Midwest Coast Drive
 

Awesome as usual. Its stuff like this that let's me honestly say you are my favorite team in FRC.

Am I the only one who just really likes that mount for the Vics? Haha.

Re: Winnovation Midwest Coast Drive
 

It's also has a set of lexan fenders coming to make a legal bumper mount system that supports the entire length of the bumper.

This project has been governed by Carrington (theloneasian) and Arthur Siebel, gotta keep training the replacements :o that dillon kid graduated.



Offseasons are for weirdo's :p

Re: Winnovation Midwest Coast Drive
 

1625: the only team not satisfied with a six wheel swerve drive

How much weight are you saving compared to that by the way?

I love running the belts through the tube. I was trying something like that but I didn't think to use belts. Makes so much more sense since you can order them an exact distance and they don't stretch or fail often.

Re: Winnovation Midwest Coast Drive
 

Looks ok, I guess...


;)

-Brando

Re: Winnovation Midwest Coast Drive
 

Just wondering, was ur belly pan desingned with the current lay out in mind? and whats with all the orage hoseing... i no u need it for the shifters but it seems like u have alot more than is needed.

Re: Winnovation Midwest Coast Drive
 

Yes, the bellypan was designed with the current layout in mind. There is a mounting layout for the electronics and pneumatics. There is probably an excessive amount of hose, but we always cut the hoses long to begin with. We will probably cut off the excess eventually.

Re: Winnovation Midwest Coast Drive
 

Ok we've been working on some things too this summer and should be posting them soon but we want to do a little testing first befor we put it out there. :)

Re: Winnovation Midwest Coast Drive
 

Looks pretty good so far. The transmission layout is rather clean. I'd be worried about the belts in the tubes though. It seems like if one were to wear or break at an inopportune time (say during Einstein finals), you'd have a heck of a time replacing it. And don't think it wouldn't happen. All it would take is one piece of sharp debris to find its way in there.

Also, I'd be very concerned about the strength of a three spoke wheel, at least with the spoke profile and material you've chosen.

Re: Winnovation Midwest Coast Drive
 

We plan on doing time trials to see how long it takes to replace a belt. We also plan on putting lexan shields over the access holes in the frame to prevent sharp debris from coming in contact with the belts. Also the wheel in the CAD is just a placeholder. The real wheels are made of UHMW that has been shelled out an only has one hole for access to tensioners.

Re: Winnovation Midwest Coast Drive
 

1/32" polycarb could be riveted over the holes to prevent debris from cutting the belts. The obvious tradeoff is increased time to repair.

What I really like about this design is the ability to change the overall gear ratio VERY quickly. In the Quals, perhaps it would be better to be faster in one match since you're the dominant robot and a low gear at 7-8fps is fine. Yet perhaps in another match you will face a superior defensive robot, thus you would opt for a lower gearing option (5-6fps low gear) in order to push through defense. 2 pairs of large pullies with respective-sized belts would be a simple way to add that versatility.

Re: Winnovation Midwest Coast Drive
 

Velcro! or the preferred 3M dual lock

Re: Winnovation Midwest Coast Drive
 

Looks great, very well put-together!

Just a thought about the belt-wear testing: you'll probably want full-grip wheels to test how quickly the belts wear out, otherwise you won't really be putting the belts under full load.

Re: Winnovation Midwest Coast Drive
 

Are you using 4 or 6 inch wheels?

Re: Winnovation Midwest Coast Drive
 

We are using SBR rough top on the wheels.

They are 4 1/2 inch wheels.

Re: Winnovation Midwest Coast Drive
 

Ah, very good, though there isn't any tread in the pictures.

Re: Winnovation Midwest Coast Drive
 

Yeah we just put the tread on the wheels yesterday.

Re: Winnovation Midwest Coast Drive
 

[quote=TheLoneAsian;972560)

They are 4 1/2 inch wheels.[/QUOTE]

Ok that's an odd size, why not use bigger wheels where u will get more speed out of ur wheels. Do u no how much the wheels weight?

Re: Winnovation Midwest Coast Drive
 

Speed & Torque are a tradeoff in electric motors. 4 1/2" wheels may be appropriate for 1625's general drive train speed/torque targets, and easy adjustments can be made by changing the pullies in the gearbox.

Re: Winnovation Midwest Coast Drive
 

Also, smaller wheels let the wheels reach a higher speed with a smaller gear ratio, which is (in theory) more efficient.

Theory is a nice place, I'd like to go there one day.

Re: Winnovation Midwest Coast Drive
 

More importantly, smaller wheels means you spend less weight on wheels AND gears, since you have less of a reduction. Luckily weight isn't that theoretical. :)

Re: Winnovation Midwest Coast Drive
 

Our wheels weigh approximately 3/8 of a pound, but they could probably be lighter. We used these wheels because they were easy for us to make and cost effective. If we built this drivetrain in an actual build season we would probably use even smaller wheels made out of aluminum.

Re: Winnovation Midwest Coast Drive
 

Great Design :D We've been thinking about doing some gear shifting too. Having the extra power would be great :D

Hopefully, next years field wont have a terrain element that cant be avoided. :/ Clearance is always annoying.

Re: Winnovation Midwest Coast Drive
 

Absolutely beautiful design and I love the idea of keeping the belts internal. We used belts the past season and they are ridiculously robust as long as you make sure they're tensioned correctly.

My question is did you broach the plastic wheels for direct drive or is there a hub in them?

Re: Winnovation Midwest Coast Drive
 

Not to mention that small wheels require less material, less tread to tread them, and often less machining time, so they're less expensive to make. (Cost isn't theoretical either :P)

Oh, and they look cool.

Re: Winnovation Midwest Coast Drive
 

That looks really pretty, but I'm a total newb when it comes to belt drives.

Can you explain it to me in a way that will allow me to teach it to a team later?

Specifically:
Why belt vs chain?
How do you tension it?
Any quick rules-of-thumb I should know about?

Or better yet, how do I tell if a belt system is good? Often, knowing if the result is good is almost as useful as knowing how to get a good result. {P=NP?}

Re: Winnovation Midwest Coast Drive
 

How hard is it to access the WAGOs on the power distribution board?

Team 234 did a presentation on their choice of belt vs chain at the championship in 2009. Here's their presentation. http://www.cyberblue234.com/document..._CHP_Forum.pdf http://www.chiefdelphi.com/media/papers/2216

Re: Winnovation Midwest Coast Drive
 

Joe, we've already compiled a list of 28 things so far to keep an eye out for, or change altogether for the next iteration of this.

And WAGO access is on the list, also thinking of more based on comments here.

Re: Winnovation Midwest Coast Drive
 

The wheels are currently hex broached through the plastic. There is a little concern that the plastic will not hold up, and if that is the case we will be making aluminum hubs.

We've never had any real problems with chain, we were just interested in some of the advantages of using belts. Some of which include weight, efficiency, and even cost. We used all Gates belts and pulleys which were donated free of cost. It is an offer that started in 2009 and you can find details about it here: http://www.chiefdelphi.com/forums/sh...ighlight=gates

As for our tensioners, the ones in the tube are a cam attached to a bolt with a roller bearing riding on the bolt. When you loosen the nut at the end of the bolt and turn the bolt then the cam presses against the bottom of the frame and it tensions the belt running inside the tube.

Here is a picture of the tensioner inside the tube:

As for the tensioner on the gearbox, It takes one bolt to tension the belt on the gearbox. The bolt just adjusts a lever arm up or down and a plastic cylinder pressed on a roller bearing tensions the belt.

Here is a picture of the gearbox tensioner:

When it comes to rules-of-thumb I'd say, from what our experience has been so far, one of the most important things is to make sure that there is proper tension.

Re: Winnovation Midwest Coast Drive
 

How are you defining "proper tension"? Is it just a feel thing or is it something measurable?

I've seen industrial definitions for chain tension which state that the chain should be able to deflect 3-5% of the span between sprockets. That definition is generally for single speed, single direction devices though. I'm not sure if it is adequate for FRC usage with the fully reversible loads with rapid speed & direction changes that FRC experiences. This method probably does work well for a belt in a tube anyway.

btw... nice work, thanks for sharing.

Re: Winnovation Midwest Coast Drive
 

Does that mean there is a vertical slot in the frame for the through bolt to move up and down on? I'm having a hard time picturing how this works.

Re: Winnovation Midwest Coast Drive
 

Yes, need to get a picture of just the bolt assembly.

A vertical slot in the tube guides the assembly up and down, as the eccentric cam washer pushes against the bottom of the tube.

The main bolt is milled to a D which the Cam washers slide onto making it as simple as twisting the bolt to tension and then locking it down.

Re: Winnovation Midwest Coast Drive
 

Is the bolt tensioner like the really cool one on the Team221 chassis rails?

Re: Winnovation Midwest Coast Drive
 

yep, where it was swiped from :p

Re: Winnovation Midwest Coast Drive
 

And 221 I'm guessing stole it from camber adjustment bolts from vehicles. My truck has the exact same bolts but about 5 times as big to adjust camber. No matter what its a great application of the cam bolts for tensioning

Re: Winnovation Midwest Coast Drive
 

http://www.chiefdelphi.com/forums/sh...ad.php?t=70473. This desgn of an 08 west coast bot looks very similar to ur design.

Re: Winnovation Midwest Coast Drive
 

West Coast Drives are very similar and extremely popular in the past few years, but every design is different in some way or another as teams and individuals eliminate different components to save weight and increase performance. And they don't look half bad either! :P

Team 254 and 968 are most famous for their West Coast Drives over the years. http://www.chiefdelphi.com/media/photos/31597

Re: Winnovation Midwest Coast Drive
 

If you spend about 5min on delphi i bet you can find alot of pictures of 6wd bases.

Ours is actually very different in the details than the one you picked, but draws lots of things from that overall style of drive.

We chose the popular criteria of 6 wheels with the center being direct driven. And having the wheels cantilevered and the frame to match.

We drew inspiration from the very proven drivetrains of 60/254/968 and added/changed things as we wished.

Re: Winnovation Midwest Coast Drive
 

I'm just simple stating a point. Nice open design with a low profile.

Re: Winnovation Midwest Coast Drive
 

Our team is currently looking a making new gear boxes similar to yours, I was wondering if u could or anyone eles could help describe to me how they work. I understand the concepts behind the shifting but I don't know what a dog gear does, or even if it's needed. Any help would be wonderful, thanks.

Re: Winnovation Midwest Coast Drive
 

I'd download the CAD models that AndyMark has posted on their site.

If you examine the models, you can see that the output shaft has a pair of gears on it, on bearings so that they are not torsionally attached to the shaft. Between these two gears is the "dog" that is torsionally attached via a hex shaped shaft. The dog has a tooth/shape pattern on it which matches a similar pattern in each gear. When the dog is pushed against a gear, they interlock, and that gear is then able to transfer torque to the shaft. The two different gears are different sizes with different ratios, so by changing which is engaged you change your reduction (and neutral would be the space between).

Re: Winnovation Midwest Coast Drive
 

To avoid confusion, the specific model Adam refers to is the AM Gen1 or AM Gen2 shifter; the AM SuperShifter has the dog gear on an additional intermediary shaft instead of the output shaft.

Re: Winnovation Midwest Coast Drive
 

Kind of curious with the post of this thread, how is this development coming along.

How is the belt routed inside the tube? Is it possible to get a picture similar to the one posted in the thread above?

Is the belt lasting? How long does it take to replace a belt?

Re: Winnovation Midwest Coast Drive
 

As far as durability goes the belts have shown no signs of wear or anything to be concerned about, and we haven't had to adjust tension at all since the first time we tensioned the belts.

We haven't had to replace a belt yet, but we are currently looking into several different methods to make replacement fast.

Re: Winnovation Midwest Coast Drive
 

I really like the unique layout of your transmission and the compact setup. You mentioned that you use "shortened body pancake cylinders for the shifters within the gearbox". Just curious...are these cylinders legal in an FRC competition robot?

Re: Winnovation Midwest Coast Drive
 

To the Winnovation guys regarding the hex broach through the UHMW wheels.1251 has a lot of R&D into UHMW material espeically regarding using them as wheels, see our 2007 robot. I can tell you the hex will not last especially playing as many matches as you guys do during a season. My suggestion is developing another keying method, bolting on alumnium hex hub adapters or just making the wheels out of alumnium. Also, avoid pressing things such as bearings or hubs into the UHMW in drive applications as the material is oil impregnated which makes doing something like that difficult, it is doable but on something that needs to be as reliable with as much torque as a drive system I don't recommed it. Overall the design is nice and clean looks like something great to build on. Good luck in 2011.

-Drew D.

Re: Winnovation Midwest Coast Drive
 

Drew,

The UMHW wheels were from the perspective of "oh hey we need wheels but don't want to spend any significant amount of money on stock" so UMHW was the cheap route taken for the prototype. During the season they would definitely be aluminum, thanks for the warnings we'll be careful using it elsewhere.

M. Mellot,

The pneumatics rules these past two years have relaxed quite a bit (as opposed to other sections of the manual :rolleyes: )
The basic requirements for pistons include,
being rated for >125psi and
"Cylinders may be of any configuration, and may be of any size up to a maximum of 24-inch stroke and 2-inch diameter."

So we're taking advantage of that rule to use a easier to integrate form factor, after all who doesn't like pancakes.

Re: Winnovation Midwest Coast Drive
 

254 and us legally used 3 position versions of the same cylinders this year, 1625 is in the clear here.

Re: Winnovation Midwest Coast Drive
 

3 position pistons? :eek:

Re: Winnovation Midwest Coast Drive
 

Yes, Mr. James 3 position pistons :D 254 used them in there drive gearbox which has 2 speeds and also doubled as their gearbox for hanging. The design work was absolutely beautiful. Not sure the use for 973 they may have done somthing similiar, Ill let Adam handle that one.

Re: Winnovation Midwest Coast Drive
 

See page 18. Pretty awesome. I didn't know these were commercially available.
http://fabco-air.com/pdf/pancake_II_web.pdf

Re: Winnovation Midwest Coast Drive
 

Oh, very cool. An OTS solution that is almost exactly how we rigged up some 3-position pistons in our last robot. Very nice indeed.

Re: Winnovation Midwest Coast Drive
 

Well, similar maybe, but the Bimba ones are great. They were so small and compact. Downside was the price, about $80 each after taxes and shipping.

For reference, 254 and us independently designed very similar gearboxes, but they were the ones who found the pancake 3 position cylinders, we were designing around the original like based 3 position which are much larger and clunkier.

We both had a dog based power takeoff on top, and we used the 3 position to nuetral the drive when the PTO was engaged.

Re: Winnovation Midwest Coast Drive
 

Thanks, everyone, for the information on those cylinders!

Re: Winnovation Midwest Coast Drive
 

"Impressive. Most Impressive."

Honestly, this looks like an awesome drive train. The gearboxes may be a much greater improvement over the Supershifters/Toughboxes that we use. And it looks like it has accommodations for a PTO for versatility. These are my first impressions. I'll need to carefully analyze this drive train, but right now it looks great! Good job.

Re: Winnovation Midwest Coast Drive
 

where you pleased with the gen shifter? I am liking the looks of the Supershifter. any problems you had with it or tips?