Chief Delphi - pic: Roborio mounting and protective case

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Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by mrnoble (Post 1403366)

A 1/16" sheet of polycarbonate will not shatter no matter what you do to it.

You know, some people might take that as a challenge...

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by Electronica1 (Post 1403369)

Could you modify the 3d printed base to include something like this?

Agreed, if you are going to all the trouble to print what amounts to something that could be made out of plywood and wood glue you might as well take advantage of the 3D printers abilities, like some sort of cable management on all sides.

Also, the 2+ in long steel bolts and nuts could be removed if you made the holes in the standoffs a bit smaller and tapped them from both ends (or tapped from just the top and just velcro the entire thing to the robot)

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by philso (Post 1403371)

Alternatively, use the case to clamp the Roborio to the bellypan and dispense with the Velcro.

That's a very good suggestion. I'll try to remember it when it comes time to design the electrical layout for our 2015 robot.

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by Alan Anderson (Post 1403410)

That's a very good suggestion. I'll try to remember it when it comes time to design the electrical layout for our 2015 robot.

Well, if you're going to enclose the Roborio somewhat anyway, what about getting some rubber/flexible 3d printing filament and making somewhat of an otter-box for the Roborio?

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by faust1706 (Post 1403360)

What if pacemakers fail after 4 years?

FYI, from someone in the industry... 4 years isn't an unusual failure rate, although most do last longer. For example, check out the SABA study (Disclaimer: I currently work for Boston Scientific): http://www.bostonscientific.com/en-U...ABA-Study.html

Quote:

This retrospective, observational study found that "the 4-year survival rate of device battery was significantly worse for Medtronic devices compared with devices from other manufacturers (94% for Boston Scientific, 67% for Medtronic, and 92% for St Jude Medical, P <0.001)."

Anyways, my point with that is... know the expectations for the part you are designing, and do your due diligence accordingly. An electrical enclosure like this is designed to shield the part from debris like metal shavings, not from robot-robot impacts. If your roboRio is exposed to impacts from other robots, this enclosure won't protect it.

Re: pic: Roborio mounting and protective case

A lot of good ideas in this thread. I was thinking about something similar last night as we are working on a project with the Sasquatch controller that is extremely exposed in comparison to the roboRIO.

We'll probably design a case soon but something that does concern me a little with this iteration is the ease of removing the RIO and a little more coverage.

For the base I would tap the bottom of the standoffs and connect that directly to the robot frame and either velcro the RIO in or use zipties but make them easily accessible. The cover I would us velcro to attach it to the base for easy removal without tools/hardware and make it a 5 sided cover that extends down to provide more coverage around the perimeter which is where you need it most. If your cover is easy to take on and off you don't need to worry about providing clearance to get your fingers in to connect wires.

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by cadandcookies (Post 1403375)

You know, some people might take that as a challenge...

Have at it. I'm sure you can freeze it to -30C and have something weird happen.

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by mrnoble (Post 1403427)

Have at it. I'm sure you can freeze it to -30C and have something weird happen.

Screw the water game, how about a liquid nitrogen game!?

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by faust1706 (Post 1403360)

I'm a programmer, but I'm willing to bet money on if you design something for industry, you have to extensively stress test it in software before implementation is ever thought of. It's kind of like with code, only it's called unit testing then. Bill Gates got so much free programming time because someone who wrote the login info to computers back then they didn't unit test their code. When prompted to put time, he simply put a letter, and the software couldn't make sense of it so he got to use the computer for free.

NASA wouldn't have gotten to where they are today if it weren't for extensive stress testing, in software and in the lab.

This isn't NASA, where robots must work in outer space for decades without maintenance. We also don't have unlimited budgets and time.

Ask any great team (1114, 254, 118, 111...) if they've done "stress analysis" on every single part in their robot. I'd be willing to be that they've only done this sort of work for maybe one or two parts on their robot.

From a mechanical point of view, this is not a simple analysis to conduct, nor would the results be very useful.

Quote:

And if you really don't want to do it, I'm sure there exists some program online that allows you to upload a cad file (I don't even know what extension they have....) and it will do it for you, or you could figure out how to do it in whatever software you designed it in.

If you're so sure, please send me a link to this program. If a solution that lets you throw in a CAD file and tells you where weak points exist, then thousands of people would be out of jobs.

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by faust1706 (Post 1403360)

This is a bit off topic, but I had an interview today for an internship for developing software. One of the questions was how I unit test (stress test) my code. It is important to do, and it could be the difference between getting a job or not. You never know.

And if you really don't want to do it, I'm sure there exists some program online that allows you to upload a cad file (I don't even know what extension they have....) and it will do it for you, or you could figure out how to do it in whatever software you designed it in.

I could easily see the quality award going to a team that has documentation about their robot's durability (and of course a good robot) How much the frame will deflect during a collision, stuff like that. It shows good engineering practice.

Unit Testing is GREAT. But it's not the end of your tests. You need to do full integration testing as well as user acceptance testing. Furthermore, writing tests is an art in of itself. I've seen lots of situations where overconfidence in our test suite let a bug slip in. Or where the tests, while exercising the code in the proper ways, weren't quite testing every data point. (This was a tool for generating QRDA CAT 1 documents from a data warehouse for patients, testing every single data element wasn't required, just the ones we needed at the time). You've also got to worry about ACTUALLY stress testing your system as well as doing security audits and tests.

I can safely say that there is NOT a tool like that. FEA is a topic entire courses are dedicated to because, not only is it hard, it's complicated to set up your simulations. Even IF there were a tool like you described I feel it would cause more harm than good because of aforementioned terrible simulations. This is a situation where your ego is going to take a bit of a bruising - the CS world is easy compared to the ME world. I say that as a programmer. We control inputs, can filter bad ones, and testing all our edge cases is fast/easy. The real world? Not so much. Testing a design is often much more difficult than testing some code.

I highly suggest reading the criteria for the Quality Award in the manual. I'd also suggest reading the sections on Industrial Design Award. While your gut feeling is mostly correct there's a fair bit more that goes into deciding those awards than what team can show the most pretty pictures of contrived scenarios.

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by mrnoble (Post 1403427)

Have at it. I'm sure you can freeze it to -30C and have something weird happen.

Or drop a little loc-tite on the polycarb.... not a pretty sight

Re: pic: Roborio mounting and protective case

Let's see: Which would possibly result in more damage from the impact of a softball:

A roboRIO with a cover

A roboRIO without a cover

?????

Any speculation out there?

Re: pic: Roborio mounting and protective case

Hey Andrew when you are done stress testing beating the covered vs uncovered roboRIO with a lead pipe can you set fire to my car so we can see how the glove-box handles hold up?

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by DonRotolo (Post 1403482)

Let's see: Which would possibly result in more damage from the impact of a softball:

A roboRIO with a cover

A roboRIO without a cover

?????

Any speculation out there?

Well, if said cover is made of, say, water balloons... :rolleyes:

Re: pic: Roborio mounting and protective case

Quote:

Originally Posted by faust1706 (Post 1403357)

I am mostly just interested in the amount of force required to break the polycarbonate sheet, as that is the most probable place of impact.

The case seems like it'd serve its purpose, to protect the roboRIO, I was just wondering how good of a job it really does. The worst case scenario the past few years would be either the 2014 game ball landing directly on it, or a Frisbee deflected into it. The latter has the potential to have a lot of force. FRC games are tough. You have to design durable parts.

If something were to magically impact this in the middle of your robot, or you were to place this on some mechanism that extends outside your frame for some strange reason, the last thing I would be worried about breaking would be the polycarbonate. The 3d printed legs would go way, way before that.

Andrew, this could actually be really neat and useful if cable management is included. If you decide to do it please update us!