How to make your robot withstand the beating

[RoeeVulcan]

This year me and my team build a pretty strong robot, but it kept getting problems with a few mechanisms that were not built to be so strong, one little match were we had a comunication problem almost disabled our robot for the entire day (take into account it was the first match of the day).

So I was wondering, what do you pro teams do to build stronger robots, that can stand the thrill of the fight?

[MrForbes]

Build several that break. Each one will teach you many things not to do. It's called experience.

If you have the opportunity to spend some time looking at some of the really good robots up close you can learn a lot. Ask questions about why parts are the way they are.

[RoeeVulcan]

Originally Posted by MrForbes

Build several that break. Each one will teach you many things not to do. It's called experience.

If you have the opportunity to spend some time looking at some of the really good robots up close you can learn a lot. Ask questions about why parts are the way they are.

I opened this thread in an attempt to learn from other teams experience, guessing they had a lot to teach me. I would love to know what your team did this year to a assure themselves on a robot that would come out of the field the same way it got in

[MARS_James]

Originally Posted by RoeeVulcan

So I was wondering, what do you pro teams do to build stronger robots, that can stand the thrill of the fight?

Some simple things that we have always done:
If you have a spare functioning robot with bumpers put bumpers on your robot before bag day and just have it sit there and get slammed a few times by your old bot. This will simulate rough collisions, and match play and also allow to see if your robot is top heavy and prone to tipping. If you lack a spare robot another option would be slamming it into something sturdy solid and unimportant.


Anything that exits the frame perimeter must meet one of these two criteria:
Is solid enough to withstand a robot hitting it, and can be quickly fixed if bent or broke.
Be flimsy enough to move out of the way of another robot.

For electronics your best bet is slow and steady. Once you know what you are building and how it will look give your electronics team the dimensions for their board and let them start building it so as you get done with your robot sections they can begin laying out wiring exiting the board. This serves two purposes, it gives the students who like electronics something to do during the whole six weeks and not just the last two, and by giving them time they won't rush which will allow for connections to be solid avoiding com issues, watchdogs and other not so fun stuff

My final suggestion is make sure your drive team knows what the robot can and can not survive. Our current robot is small so we could use thick aluminum this year for our structure and everything above it was made from thick sturdy PVC board that has now gone through two regionals and championship without a bend or crack with heavy defense being played on us when ever we go out. However last year we were long and tall so when ever (rarely) someone would play defense on us we had to avoid and evade so to avoid unnecessary damage.

[Daniel_LaFleur]

Originally Posted by RoeeVulcan

I opened this thread in an attempt to learn from other teams experience, guessing they had a lot to teach me. I would love to know what your team did this year to a assure themselves on a robot that would come out of the field the same way it got in

Ok, I'll give you a few tips. Depending on the game and your robot design, they may or may not apply though.

1> The KoP frame is very strong in the x and y directions but is flexible in the z (specifically twisting in pitch and roll). This could allow the frame to permanently deform with the 'vigorous interaction' with other robots (or this year ... falling). We usually box our frame. That strengthens it (and makes it heavier) and gives us a second deck to attach devices.

2> If you don't have to cantilever your drive system, don't. If you do, then calculate the twisting forces (especially side loads) and make sure your gearbox mounts can handle that.

3> If you use the c-channel, wherever you attach something put a wood block (or other support) into the c-channel. I've seen too many crushed and twisted c-channel frames in my day

The last one is just a guideline: When building something to survive impacts it must either be strong enough to withstand it or flexible enough to not care.

[pfreivald]

Solder is better than quick disconnects.
Electronics should be well-protected from 'vigorous interaction'.
Don't skimp on material where you need it (this is largely an experience thing).
Drive it like you stole it, before you bag it!

Make it out of steel.

/thread

[Golto]

Consider your center of gravity. A lot of damage comes from tipping (or falling). The bumper rules are in place to help alleviate the hit damage, worry about not damaging yourself and you'll build a fairly sturdy machine.

[DonRotolo]

Being in MAR, we go through up to 18 matches in each of three events (=48 matches) plus CMP and maybe a regional too... we need to hold together for maybe 80 matches! So building durable is required.

If you can, build a practice robot. It does not need to be perfect, just about the same as the production robot. We often use a previous year robot. Then all the prototype mechanisms get mounted.

Then beat the snot out of it. Slam it into walls, hard reverses and turns...try to break it. When it does, fix it stronger. Repeat until you are almost out of time.

Then build the final robot. Remember, it does not take as much time to fabricate the robot as it does to design it, so for the production robot we KNOW what needs to be built, it does not take long to build it.

As you can guess, it does not break often.

[Jeffy]

The most common thing to fail is the drive base. We try to complete it by week 2 or 3 and spend any free time slamming it into walls. Err... I mean programming autonomous.

[EricH]

Speaking for just about anybody who played before 2006: Bumpers are for wimps. Ignore them when designing, other than to place mounts.


That said, you start by designing protection for all critical systems. Use safety factors well above 1, say around 3-4. (Even use fatigue safety factors--that will help with keeping everything functional.)

Use shielding liberally--nothing worse than someone's arm going in and shredding electronics, unless it's your shooter wheel disintegrating while uncontained.

Have spare parts that can be installed very quickly. The hardware will be too intimidated to break. I know my team had a spare arm that could be swapped in by pulling a couple of bolts and a couple of air lines, pull out, push the new one in, reinstall the bolts and air lines, start play. Never once had to use it--so we let the MC show it off for us on the field before a big match.

[pfreivald]

Originally Posted by EricH

Have spare parts that can be installed very quickly. The hardware will be too intimidated to break.

That's a good point -- design for ease of maintenance and, in the process, modularity.

[blayde5]

Kinda unrelated but avoid metal shavings getting into your electronics at all costs! This has cost many teams matches.

Bumpers with their 3/4" plywood turn out to be very strong so if you can have a solid connection between your bumpers and frame perimeter, it'll beef up your chassis

[s_forbes]

Originally Posted by Jeffy

The most common thing to fail is the drive base.

That depends... We had exactly 0 issues with our drive train this season (first time that's ever happened). We used the AM kit frame.

A good way to minimize the possibility of breaking things is to minimize the number of things that can break. In general, simpler designs will need fewer parts and end up being a little lighter, so you can use that saved weight to build with beefier materials.

[cbale2000]

"How to make your robot withstand the beating"

3/8" polycarbonate... just sayin...

http://goo.gl/8UNqE