Introducing Revolution Pro...crab/swerve module

[ajlapp]

Some of the pictures on the product webpage don't seem to match the main product picture or the PDF. ( http://www.team221.com/upload/king_crab_detail.jpg )They apparently use the older revolution swerve design at least for this pic. (and I doubt that the new design would even work on this platform because it's so much shorter, no height for a CIM)

Also the PDF shows the input as 3/8 keyed shaft while the product picture ( http://www.team221.com/upload/revolution_pro.JPG) has a hex input.

Uploading a CAD model would explain these discrepancies I'm sure.
Reply With Quote Multi-Quote This Message Quick reply to this message

Good observations. The image on the main page is of the original prototype. It had a 1/2" hex input on the vertical drive shaft. The production version sticks with the 3/8" keyed shaft.

The images of the complete robot are really just for reference. We just finished building it...it used a classic module. The new modules aren't quite ready.

I will post some step files soon.

Am I the only one who thinks both the new module and the new platform they built are disturbingly similar to designs I've posted here within the last year?!

Many posters in this thread have addressed your statements. Unfortunately I haven't seen your designs. I'm sure they are similar in many ways...as are most swerve derivations...but this is definitely a coincidence.

As for the platform design, I did my first one in 2010. I slowly modified and improved the design over the years. You can see our custom creations here.

http://www.team221.com/order.php?cat=10

[magnets]

Originally Posted by Bryce2471

My observation was more based on the large amount of optimizations that appear in my posted designs. Not on completely brand new ideas that have never been seen before.

You pointed out that your designs were disturbingly similar, implying that the Revolution swerve module had somehow copied yours.

1. It uses a small diameter solid treaded wheel.

Excluding 2009, show me a swerve drive that does not use a wheel with a tread. Teams have been using small wheels since 2008 (http://www.chiefdelphi.com/forums/sh...ad.php?t=64824)

Here's a team using a 3" wheel: http://www.chiefdelphi.com/media/photos/38289

2. The wheel is off set slightly to one side so it can be nested by the miter gear.

See 148 in 2008. The wheel is off center in that design.

3. It utilizes straight cut gears instead of a chain to transfer power to the wheel.

See 148 again.
Or this one: http://www.chiefdelphi.com/media/photos/37005

4. It uses a dead axle to keep side plates light weight.

See this design: http://www.chiefdelphi.com/media/photos/34443
Or any 118 robot since 2005.

5. The wheel axle is a hallow stand off to increase the strength of the module and make replacing the wheel easy.

See the old revolution swerve design.
Also, this drawing shows that their wheel axle isn't hollow. (http://www.team221.com/upload/445-Revolution_Pro.pdf)

1. It uses a single extrusion upper frame.

221 Robotic Systems has used this frame before you have.

2. It's CIM motor is behind the steering motor, in an in-line configuration.

Where else would you put the steering motor?

3. CIM chain runs around the steering shafts to get to the main double shaft.

118 has done this in 2007.

Excluding this and Aren Hill's in wheel CIM swerve, most swerve designs are very similar, or fall into a few categories.

[Bryce2471]

Originally Posted by magnets

You pointed out that your designs were disturbingly similar, implying that the Revolution swerve module had somehow copied yours.

I'm sorry, that's not what I was trying to imply.
I'll quit posting in this thread now, sense it seems like I'm just making it worse.

[cadandcookies]

Alright guys, give him a break. I think he gets the point.

Andrew, I'm loving the updated design! Seems very efficient and compact. If I'm ever on a team considering swerve again it'd definitely be the top candidate. The updates have really modernized the design, and I really like that it shows off what you can do with mostly COTS parts.

[Jared]

Originally Posted by cadandcookies

Alright guys, give him a break. I think he gets the point.

Andrew, I'm loving the updated design! Seems very efficient and compact. If I'm ever on a team considering swerve again it'd definitely be the top candidate. The updates have really modernized the design, and I really like that it shows off what you can do with mostly COTS parts.

Agreed with both points -most swerves are quite similar anyway.

I really like this design. It's just simpler and smaller.

[cjl2625]

Nice, we used the Revolution modules for our swerve this year.
I see that you ditched the chain connecting the wheel to the top part thingy. I like that; we have had a bit of problems with the chain coming off.

[Aren_Hill]

Originally Posted by magnets

Excluding
this and Aren Hill's in wheel CIM swerve, most swerve designs are very similar, or fall into a few categories.

Entertainingly enough, I sent a concept to Kevin back in April of this layout, he just made a 2 speed version and posted it first.

I'll post mine sometime in the near future.

-Aren

[ajlapp]

STEP files are now posted.

http://www.team221.com/viewproduct.php?id=147

[nathannfm]

Originally Posted by ajlapp

STEP files are now posted.

http://www.team221.com/viewproduct.php?id=147

Thank you so much for this, I took a cross section and noticed there is a 1/2"id bearing right above the vertical bevel gear that doesn't seem to be doing anything. If it were 3/8 it would be guiding the shaft which would make sense, am I missing something? I also noticed there are no thrust bearings anywere, only thrust bushings, I guess you have found this to be acceptable?

Also, in the prototype with the hex shaft sticking out the top how did you manage to assemble that without using larger diameter hex bearings and thus a larger overall diameter?

[ajlapp]

Thank you so much for this, I took a cross section and noticed there is a 1/2"id bearing right above the vertical bevel gear that doesn't seem to be doing anything. If it were 3/8 it would be guiding the shaft which would make sense, am I missing something? I also noticed there are no thrust bearings anywere, only thrust bushings, I guess you have found this to be acceptable?

Looks like a modeling typo. It's the same 3/8" ID bearing shown at the top of the stack. Thrust bushings are the answer. We used them on the classic Revolution and they performed great. Actually a lot of swerve guys think you can send the thrust loads directly into the ID of the bearing....I like the additional overhead that the bushing provides.

Also, in the prototype with the hex shaft sticking out the top how did you manage to assemble that without using larger diameter hex bearings and thus a larger overall diameter?

The shaft was 1/2" hex to 1/2" round to 3/8" hex. It used a 1/2" ID x 7/8" OD bearing....the same one incorrectly shown in the model actually. Vexpro sells them. We changed back to the keyed shaft as the original design was cost prohibitive.

I've updated the model with the correct bearing.

[nathannfm]

Originally Posted by ajlapp

The shaft was 1/2" hex to 1/2" round to 3/8" hex.

The fact that a shaft like that was actually created makes me smile, I never even considered that lol

[AdamHeard]

Originally Posted by nathannfm

The fact that a shaft like that was actually created makes me smile, I never even considered that lol

You'd love every one of the shafts on our 2012 robot then.

[nathannfm]

Originally Posted by AdamHeard

You'd love every one of the shafts on our 2012 robot then.

I really need to look at your CAD more

*finds 2012 drive*

I...wow, that drive...all questions, no answers...

https://imgur.com/qubH6NJ

[AdamHeard]

Originally Posted by nathannfm

I really need to look at your CAD more

*finds 2012 drive*

I...wow, that drive...all questions, no answers...

https://imgur.com/qubH6NJ

I don't think our 2012 ever got posted, but I should get on that.

What you linked is one of our WCD drive shafts. Fun part. We generally have a sponsor make them, but we've had students make them (and similarly complex parts) in house on our manuals.