Weight Reduction

[lukevanoort]

Replacing steel bolts with aluminum versions. Very light and still strong enough for most purposes.

[Elgin Clock]

Originally Posted by lukevanoort

Replacing steel bolts with aluminum versions. Very light and still strong enough for most purposes.

Replace Aluminum bolts with Nylon ones.

Even better for some applications.

You don't really need a steel or aluminum bolt holding down the RC now do you?

Use 2 screws on muffin fans instead of all 4 corners.

TRIM THOSE WIRES!!! You don't need 1' of cable going from your battery to your quick connect if the battery is right next to the breaker.

ONLY SWISS CHEESE THE BOT IN WEEK 6!!!!!!
None of this "speed holes in week 1" nonsense!!!!

You can't put material back as easily as you can remove it if you need to mount anything, even something as simple as a potentiometer, limit switch, or a sensor of some kind.

[Jonathan Norris]

Rivets, we were able to take almost 5 pounds of bolts off our robot last year by replacing them with rivets. Also choose your materials wisely, sheet metal is your friend, too much extruded aluminum is not. Even if you are not at the cheesing stage yet with your build, plan our where you can reduce weight if you have to, and expect to have to take apart your robot a couple of times throughout the season (keep welding till you know your weight).

[Joel J]

Corrugated lexan (green house material) instead of lexan for side shields, and coverings..

[Brandon Holley]

Heres a fun story from the Nu-Tron from around 4-5 years ago:

They brought the bot up to inspection and placed it on the scale. The scale read 130.0....130.1....130.0....130.1 (for all you youngens back in the day the limit was 130 pounds WITH a battery). Eventually the scale stopped at 130.1. One of the team members decided to check the air tanks, they were full so he released all the air pressure...the scale dropped to 130.0 and they were good to go. Moral of the story: EMPTY YOUR AIR TANKS!

[Robo_Coyote]

This year Team 1323 was able to cut 11 lbs of our basic chassis by welding our frame together it was a task our team was shooting for since the end of last year when we invested in a tig welder.

[Ben Piecuch]

We've used some fairly large bolts in the past to mount various mechanisms, wheels, etc... A 1/2" bolt is typically overkill in terms of strength, but the diameter has been our requirement. So, we've actually drilled out the center of our larger bolts in order to reduce the weight of this large hardware, and it definitely works.

YMMV, good luck.

BEN

[MattB703]

We have a saying that we use over and over when looking for weight reduction;

Steel parts first, then alluminum, then plastic.

Cutting/drilling holes in a 1/8" lexan side plate for instance is pretty inaffectual. On the other hand, putting a gear or sprocket in a lath and taking some "meat" off it can pay big dividends.

[s_forbes]

Our team is working hard to actually predict weight of the final design in order to avoid the problem we had last year. Every piece is being designed with speedholes included, so hopefully when it all goes together it will be underwieght.

In case anything is heavy and still has room for holes at the end of the build, we have a Rotex punch which can be used to speed up the cheesing process.

[robotguru1717]

This year it already looks like we are having weight issues so we have been taking the weight of EVERYTHING (components, motors, spikes) and adding them into an excel file. Then for things that arn't built yet like the chassis, wheels and stuff we have done extrememly acurate Solidwork models of them and these give us the weight.

#1 tip to avoid overweight issues:

Plan/design everything first then build. dont design as you go.

[RichardJames]

weight relieve every sprocket, pulley, gear, and gear box that you can. weight relieve all aluminium and lexan plates. These are some of the densest things on most people`s bots. also, make sure you are using gears belts or chain that is appropriate (not overkill), as jumping up to the next strongest category can mean doubling the weight of these components.

[maltz1881]

Just as a funny story although it wasn't funny then. When i was with a now defunct team we had an engineer who insisted we had to use 1/4 in thick aluminum for our sides. This was several years ago when you could only weight 130 with your battery. I told him many times it wasn't necessary to go with something so heavy. He still insisted. When we finished the robot we weighed it and came in at a whooping (are you sitting down!!) 217 lbs . What could I say other then I told you so which of course I didn't. Shaking my head and handing out the sawzalls we made it down finally to 130 on the dot. It only took us 9 days of making swiss cheese out of EVERYTHING. Needless to say that engineer was never seen nor heard from again.

[Cuog]

Programmers: Get rid of that White space, no comments. Those extra electrons are killing us

file everything smooth, I havent teste4d it but im sure of you filed everything on the robot to a smooth surface almost a half pound of dust would be removed.

[Brian C]

Just as a funny story although it wasn't funny then. When i was with a now defunct team we had an engineer who insisted we had to use 1/4 in thick aluminum for our sides. This was several years ago when you could only weight 130 with your battery

Team 190 had their robot a couple of years back where pretty much the entire chassis was made of Lexan.

You can do some pretty cool stuff with Lexan........

[Otaku]

What to do:
-Mill your chassis. This might not come in to the minds of rookie teams or people who just haven't done it, but it can shave off a lot of weight, oh, and it can even make handles on your robot (but I don't suggest that).
-Speed holes in week 5/6. Cheese-grater robots are still robots.
-Calculate everything. You won't need to make speed holes if you figure it all out beforehand and get it taken care of.
-Use thinner material, or use it smarter. I'll leave this for you all to figure out.
-Lop off excessively long shafts or bolts. It might add up to that crucial pound or two.
-Use lighter parts. Aluminium sprockets, thinner gague wire where thick stuff isn't needed, etc.
-Plastics are your friends. Lexan/Polycarbonate/Plexiglass instead of actaul glass (why would you want it?) or aluminium.
-Minimize Pneumatics. They're heavy and ineffecient.
-Minimize Chain. It might not weigh a bunch on it's own, but it will add up.
-If all else fails, Nitroglycerin. Sure, you might not have anything competition-worthy afterwords, but you'll be under the limit.

Tools you will need:
-Drill
-Angle Grinder
-Dremel
-Nibbler (Maybe?)
-Mill (CNC, Precision, or otherwise)
-Files. Lots of files. Straight files, round files, cylindrical files. Single cut. Double cut. Bastard.


That should help. Oh, and good doses of common sense will help you out, too.