Re: pic: 2011 Drive Prototype
 

Hm. Really?
- Cam actuated tensioners? Check.
- Self locking style cams? Check.
- 2x1 frame members surrounding semi-elliptical bearing blocks? Check.
- External cantilevered wheels? Check.
- Center wheel direct driven? Check.
- Two speed custom gearbox? Check.
- Belly pan for electronics, cut on a waterjet/laser? Check.
- Welded sheet battery box? Check.

I could keep going on. Are you SURE it's not a copy of the 254/968 system?

Re: pic: 2011 Drive Prototype
 

Ok #1 Its the concept that i copied, not the design. there are many differences in my design versus 254's. While the design was heavily inspired by 254, it is not a copy. What i did was i took the concept and adapted it to suit my own needs. The Belly pan's cut out pieces are different sizes, the bearing blocks are different dimensions, work a little differently and have smaller radiuses... Pretty much all the things that you listed were concepts not total designs. Anyways who hasn't used a 254 concept in their career in FIRST.

Re: pic: 2011 Drive Prototype
 

That would be a 233 design cue. Far too many people see our robots from the last 2 years and think it's our idea. Just one of the many we've borrowed from other great teams over the years.

Re: pic: 2011 Drive Prototype
 

Don't you even use 233's Water jet? So technically you're borrowing their machines too!

Re: pic: 2011 Drive Prototype
 

Having talked to Marcus and seen many of his design iterations before this post, I know he understands many of the intricacies and benefits of a WCD design. True, there have been many posts on CD lately of "pretty renders" of chassis designs that seem to have very little thought put into working out any of the details, but I can assure you this is not one of them.

Sorry Marcus, I will have to agree that this design is heavily inspired by 254/968, and you should own up to it. But to everyone else, while Marcus has not created an entirely new chassis design, I am glad that he has taken the time to actually analyze 254/968's design and ask himself why certain things are done the way they are (for example, why the cams are tensioned counterclockwise as opposed to clockwise) and do proper drive train calculations.

I think that a perfect place to start is to look at examples from great teams like 254/968 and try to figure out the thought process that led them to their final design. Only then can someone start to be innovative. And as a first year FRCer, I think Marcus is doing a great job at that.

Now let's get back to some constructive criticism. :)

Re: pic: 2011 Drive Prototype
 

Good to know. We've done some kind of belly pan since 2005, but never has it been waterjetted to such accuracy.

Re: pic: 2011 Drive Prototype
 

That's correct. 233 has waterjetted numerous parts for us the last two years and we help them out by making things for them whenever possible.

Re: pic: 2011 Drive Prototype
 

Like wheels for their practice bot... right?

Re: pic: 2011 Drive Prototype
 

We manufactured a number of drivetrain components for them this year.

Re: pic: 2011 Drive Prototype
 

Why was that? Was it because you used similar components and you already had the g-code written. So it was faster and more efficient to do them all at once?

Re: pic: 2011 Drive Prototype
 

You seem to be missing the point. What style of bearing block you use or how big the cutouts are doesn't matter in the grand scheme of the design. If I took this design, changed around what type of bearing blocks were used, changed the shape of the lightening holes in the belly pan, and used a different shaft size, would it be a different design?

Re: pic: 2011 Drive Prototype
 

Yes, it would be a different design. I never said that i didn't get inspiration from 254 or that it wasn't their concept i just meant that it's my version of their design.

Re: pic: 2011 Drive Prototype
 

Alright, I would personally view it (and it appears several others do as well) as the same design. I accept that you think of it as a different design though.

Re: pic: 2011 Drive Prototype
 

Grandfather's axe is handed down from generation to generation. Every now and again, the head or the handle is replaced due to normal wear and tear of use, with a slightly differently shaped head or handle. At what point does it stop being Grandfather's axe?



I'm not going to say that you didn't get inspiration from 254. I don't think anyone ever did say that. What got people annoyed was that you made mostly cosmetic changes, and then appeared to claim that because you made some small changes, it was your design, not 254's. Again, this is simply the impression I got. See the Grandfather's axe answer area above--I think we're on two different answers here.

BTW, 330 has yet to use a WCD design. 6WD? Yes. Shifting? Yes. Direct drive to the center wheel? I can't say I remember one--possibly in 2009, which wasn't a WCD design any way you look at it. Cantilevered? Nope, I can't think of a single 330 robot using a cantilevered wheel. Battery box? A couple of times, but I don't remember materials, etc. Belly pan? Well, we do use a plywood base for strength and mounting stuff... But no tensioners of the cam style, let alone embedded in the frame rails. Elements, we've used. Design, we haven't.

Re: pic: 2011 Drive Prototype
 

For a number of reasons. We had wanted to do some sort of collaboration with them on a summer project for years but had never been organized enough to make it happen. We both were going to make similar drivetrains and we were already making about 8 sets of everything so it didn't make it any more difficult for us to make 10 of the components common to both teams.