Robonauts CAD
 

I've just found this out, and I thought I'd post it here because it was really useful for me.

The robonauts have put up CAD models of their 2007, 2009, 2011, and 2012 robots, which are really neat, very detailed, and some of the best CAD work I've ever seen from an FRC team. I now know how their massive gearbox in 2007 works!

You can download them from here
http://ccisdrobonauts.org/?w=1600&h=900&p=robots

Re: Robonauts CAD
 

I really wanted to see the CADs of their 2013 and 2010 robots. Hopefully that's going to happen.

(Also, those huge STEP files should probably be delivered compressed—they'll be about 10% of the size.)

Re: Robonauts CAD
 

Agreed on those request.

Also agreed on .zip for step files. It's AMAZING how efficiently they compress. It's fun actually.

Re: Robonauts CAD
 

there goes the rest of my day. Seriously love how amazing 118's bots are. I hope 118 post the CAD of the side bridge mechanism from 2012, that thing was really cool even though it got the ruled as illegal. Probably the most inspirational FIRST robot mechanism to only to be used in a practice match.

Re: Robonauts CAD
 

Yeah, looking back, that was totally unfair to make it illegal.

Re: Robonauts CAD
 

I wouldn't say totally unfair. The game manual did say no "grappling" on the bridges. Different people had different interpretations of what constituted grappling, and so by making the mechanism 118 took a risk.

Re: Robonauts CAD
 

This is incredible. I don't think a single robot has had a bigger impact on my team than Robonaut 2012, and now we can check out the CAD! Thanks so much to an incredible team for posting these models.

The unfair part is when multiple teams repeatedly asked FIRST for a definition of "grapple" and FIRST wouldn't provide it. The ruling on "grapple" in 2012 also relied on a different definition than 2011.

Re: Robonauts CAD
 

I was watching a piece on the BBC website about 3D printing this afternoon and noticed a short clip of a complete CAD of Endeavour as well as a closeup of a wheel I believe.

http://www.bbc.co.uk/news/technology-25101388

Re: Robonauts CAD
 

Wow, that's really cool! For those interested, 118 shows up around the 2:15 mark.

Re: Robonauts CAD
 

That is interesting...

I don't recognize that CAD operator or the area that he is working in. I wonder where that footage is from?

Ironically enough we didn't use 3D printed wheels. We 3D printed a positive mold tool then cast the wheels from a different plastic.

Still cool to have something I designed make it into the video though.

Also, we're working on updating the CAD files on the website. For now you can get them here:

https://www.dropbox.com/s/khh6lcfynt..._asm_6week.zip

Re: Robonauts CAD
 

Wow. The 2013 CAD is really impressive. I can't say that I've ever seen a cooler and more detailed CAD of any robot. Literally every thing on the robot is in the model.

I'm a huge fan of your gearbox. I don't think I've ever seen another team use a dog shifter between a gear and a sprocket.

Just out of curiosity, how do you guys work with these massive files? It took me a good 10 minutes just to open it, and I have to look at individual assemblies or it is too slow. Does solidworks do a better job than inventor with big assemblies? For me, inventor uses 5 gb of RAM just to have the file open.

Re: Robonauts CAD
 

Ditto, I'm having fun just exploring the model. SO many impressive details.

Question, I'm looking at the "Magic Maker", shooter angle flap. Why both the string and 10 turn pot? Redundancy? Flexibility to choose one or the other on the final product? Something I'm totally missing?

Another question, was Apex single speed? From what I can tell, the dog shifts between DT and Climb Wheel.

Thanks so much for posting these models! Can't wait to show my kids on Wednesday. This is inspiring stuff.

-Mike

Re: Robonauts CAD
 

We use Pro-E. The models get sluggish but people rarely work inside the complete model.

We divide the design and modeling tasks amongst the individual mentor leads. They're responsible for their sub-team's assemblies. We define a coordinate system for the robot...you essentially build your parts at your default location. When you bring each sub-assembly into the master you can drop it at "default" and it goes where it belongs.

Not everyone is a professional designer though, so we have one group that manages the master model and integrates to make sure we have no interference issues.

The "macker" or deflector used a pot for positioning. The string pot in the model is from an early design. Conceptual features aren't always removed from the model.

Re: Robonauts CAD
 

So I was examining this CAD model in all its glory, and I noticed that there weren't any visible chain or belt runs on the drivetrain.

At least until I looked inside the long chassis rails:


Maybe I'm missing something, but how did you get your chain in there? Also, did you have any issues with running 6 CIMs on the drivetrain (current draw popping the main breaker for example)?

Thanks for posting this model, really appreciate getting the opportunity to look at 118's amazing work!

Re: Robonauts CAD
 

They switched to 4 CIM + 2 Mini CIM after they took their climber off

Re: Robonauts CAD
 

You drop the chain and sprockets straight into the tube from one end. Then, while the sprockets are approximately in position, you slip your shaft into place and put the backside bearing in.

We ran this setup all year without maintenance.

221 Robotic Systems is launching a production version based on this design for 2014. Personally I loved the space we gained back by moving the chains inside and the weight saved by removing the tensioning device.

Re: Robonauts CAD
 

Wow, I did not think internal chain like that without tensioner a was even possible. I can't believe the chain never stretched or loosened. The space savings over internal timing belt (not to mention cost) means my team will have to seriously consider this as an option for 2014.

Re: Robonauts CAD
 

I'm sure it did loosen over time...likely due to sprocket wear. However, it can't go anywhere. It would have to eat away the tubing to jump off.

FYI...I'm quite sure FRC233 has been doing this for a while. There may be others too.

Re: Robonauts CAD
 

340 has been doing it for the past couple of years too.

Re: Robonauts CAD
 

It was definitely cool to see at IRI, and just made quite a lot of sense. I was surprised to have not thought of it before.

PS - I always tell this to people who ask me about 118, but Anthony gives THE BEST robot tours. I look forward to it each time I see them.

Thanks for the CAD!

Re: Robonauts CAD
 

In the unlikely event of a chain breakage, how long would it take to replace the chain?

Re: Robonauts CAD
 

Theoretically it should be impossible to generate enough traction at the wheel to overcome the tensile strength of the chain.

That said, it didn't look plausible to us to replace a chain in the heat of battle.

So, to give ourselves comfort we built a complete chassis in the pre-season to test the setup. This included stress testing the chains by continuously going between max forward and reverse torque. We survived this testing without incident.

Both the practice bot and comp bot went the whole season without a blown chain. Once I recall we had a chain jump the sprocket and jam...this was determined to be cause by a rivet body that had made its way under the chain and sprocket....it was resolved without removing any parts.

Does anyone sell that double sprocket as an off the shelf item or is that custom?

Re: Robonauts CAD
 

It is custom, but I believe 221 Robotics Systems will be offering it separately with a keyed bore.

Re: Robonauts CAD
 

Soon.

SimpleTube Chassis System

Re: Robonauts CAD
 

Any idea when the sprockets will be available?

Re: Robonauts CAD
 

The whole chassis system and it's accessories are scheduled for kickoff weekend.

The current plan is to offer all of our popular transmission options, 6wd, 8wd and several size options.

Re: Robonauts CAD
 

Looks like the 2013 robot and the SimpleTube chassis don't have the center pair of wheels dropped - how are you avoiding wheel scrub during turns? Looks like all of the 118 wheels are the same dia - do the custom wheels have a low lateral CoF?

Re: Robonauts CAD
 

The Robonaut wheels were not the same diameter. The outer wheels were approximately 1/2" smaller in diameter. The CAD may not reflect this.

The internal geometry of the double sprocket does not allow for any drop.

SimpleTube will use this same arrangement of different sized wheels.

Re: Robonauts CAD
 

Does that difference in wheel size cause faster wear on the wheels because of difference in speed? I ask because I noticed 118 had a lot chunks taken out of their wheels at SVR before they replaced them.

Re: Robonauts CAD
 

Theoretically with the center 2 wheels larger than the outer sets and the CG of the robot is between the center axles they are the only set of wheels in contact with the ground; with the exception of directional changes and rapid acceleration changes where those outer set of wheels technically act as a powered wheelie bar.

Yes, there will be some pulling/dragging of wheels for brief moments due to difference in diameters. With this setup you should expect your center 2 wheels to wear faster than the outer set of wheels.

I cannot speak for the 118 specific wear issue though.

Re: Robonauts CAD
 

I'm having some issues seeing the file. After I download it, it won't open in AutoCAD...

Re: Robonauts CAD
 

Not sure if joke, but you'll need a 3D parametric CAD program such as SolidWorks, Inventor, or Creo, plus a lot of RAM (around 12 gigs at least for 2013 model).

Re: Robonauts CAD
 

I wish it was a joke. I'm completely new to the Autodesk world and was hoping that by looking at some quality work I might be able to learn something.

Re: Robonauts CAD
 

I have a few questions:

How long did it take to make the autocad file?
How long did it take to cut out all the parts and powdercoat them?
How long did it take to assemble?
How long did it take to make the code?
Who worked on it? (NASA engineers, students, teachers)?

Re: Robonauts CAD
 

Very nice detailed model!

If you are a student, you can download Autodesk Inventor free from: http://www.autodesk.com/education/student-software.
You will need a good computer though. Any 3D CAD software needs a dedicated graphics card and lots of RAM. The 2013 Robonaught model took up 7GB when I opened it.

Re: Robonauts CAD
 

Thank you for the link! I already have AutoCAD but I couldn't find Inventor on their website.
I also recently bought a wonderful HP built specifically for CAD and my programming needs so I think I'll be okay:)

Re: Robonauts CAD
 

If you following Chris's (luckof13) link, click on free software on the left-hand side then scroll down to "Inventor Professional" and select the one you want.

Let us know if that doesn't work! :)

Re: Robonauts CAD
 

Excerpt from FRC Designs: http://frcdesigns.com/2013/12/17/rob...n-frc-designs/

Re: Robonauts CAD
 

FYI...

We've updated the CAD files available on our website.

Our robot changed quite a bit during the season, so we uploaded a file of the robot at the 6 week ship date and one from Championships.

Re: Robonauts CAD
 

Thanks!

Just a quick question, what was the "double hang" assembly? Was it ever used?

Re: Robonauts CAD
 

I've always been curious about how this affects pushing matches. In a pushing match there will be a much larger force on these wheel and it's crucial that they keep traction. Wouldn't it be impossible to maintain static friction on both of these wheels in this instance?

Re: Robonauts CAD
 

Just wanted to express my gratitude to 118 for releasing these models. They really are the sort of thing one can get lost exploring. The depth is just amazing.

Re: Robonauts CAD
 

That was a device to achieve a second rung hand using only stored energy.

The device was built and tested on a practice robot but never made the field.

Re: Robonauts CAD
 

That sounds really cool. As I recall the only other team that attempted a stored energy climber past the first rung this year was 1323. Anything you can tell us about the design of the mechanism or why it wasn't implemented?

Re: Robonauts CAD
 

"Apex" is every bit as intricate and amazing on its insides as it appeared in last winter's reveal video.

Thanks a million for posting these. They are a true pleasure to study.

Now to download and explore every single other CAD model posted by 118...