Tips on loosing weight (Not spam)

I recently learned about these: http://www.pneuaire.com/reca44cuin.html pneumatic air tanks that are both light, and effective. My team is big on saving weight, and would like to be able to more control what our robot weighs without drilling 30,000 holes into it.

So, what are your secret tips on saving robot weight?

[Gary.C]

Save hella weight - buy aluminum gears

[CNettles11]

Use a stick on a motor whenever possible

[EricH]

Take a spreadsheet and a scale. Weigh every part, and estimate weight where you can, before the part goes on the robot. As you figure out you're close to being overweight, figure out where you can trim weight.

[O'Sancheski]

Originally Posted by EricH

Take a spreadsheet and a scale. Weigh every part, and estimate weight where you can, before the part goes on the robot. As you figure out you're close to being overweight, figure out where you can trim weight.

I did this in 2010 and works great. You gotta make sure to get the exact weight on each part and classify large pieces of wood/ aluminum based on weight per foot or inch to avoid confusion in the middle of build season.

P.S. It is very time consuming to weigh each part.

[BrendanB]

Originally Posted by EricH

Take a spreadsheet and a scale. Weigh every part, and estimate weight where you can, before the part goes on the robot. As you figure out you're close to being overweight, figure out where you can trim weight.

Can't echo this enough! Having a reasonable weight budget for subteams to stick too is key along with having an allowance for essentials like electronics and such.

Keep weight savings in mind while you are building/designing. Our team ate up weight fast on 1x1x1/8 aluminum box that could have easily been replaced by 1/16 but it was too late to change.

It is also a whole lot easier to swiss cheese while the part is not yet on the robot!

[ajlapp]

Team RUSH hasn't used pneumatics in their robots since 2004 and this has been a tremendous weight saver in my opinion.

Initially we stopped using them because we thought the package available at the time was too heavy for the utility you achieved. We would often have one or two systems that were candidates for pneumatics....this didn't justify adding the ~8 lbs. needed for the compressor, tanks, hose etc, etc. Of course we discussed eliminating the compressor for some designs, but in the end we just eliminated the whole system.

Originally I hated that we didn't have access to pneumatics...each year I would lobby for it. Now that I recently started helping a new team, I find myself lobbying them to eliminate it to save complexity and weight.

Of course a lot of teams are able to integrate all motors and a complete air system while staying in weight, but it's a very liberating feeling heading to scales with 8-10 lbs. to spare.

Now that the systems have become more open and lighter I'm sure we'll take a serious look at going back.

[amoose136]

Would any team care to post a past weight budget? I'm curious to see the average weight composition of the FRC robot.

[artdutra04]

Design everything ahead of time in CAD. If you set the materials appropriately, you can get an accurate estimate of your final robot weight. The more detail stuff you model, the more accurate the weight estimate will be. Changing designs in CAD to reduce weight is much easier, cheaper, and more effective than having to drill hundreds (potentially thousands) of holes in your mechanisms after they're already assembled.

[s_forbes]

Originally Posted by artdutra04

Design everything ahead of time in CAD...

Quoting this for truth! Not only do you have the benefit of part masses being calculated quickly, but you also have the ability to alter and optimize the design on the fly. On all of the better robots that I've been a part of designing, weight was never even considered; we spent so much time creating an efficient design that weight didn't need any attention. A good design will by lightweight by nature.

It always amazes me how so much attention is spent on eliminating fractions of a pound in the drivetrain when usually much more can be saved with an efficiently designed manipulator. Remember to design the robot as a whole and not just each part independently.

[Wayne Doenges]

One word...Monocoque
No internal frame.

[ratdude747]

Originally Posted by Wayne Doenges

One word...Monocoque
No internal frame.

sounds like most cars anymore... unibody anybody?

[JamesCH95]

Originally Posted by s_forbes

It always amazes me how so much attention is spent on eliminating fractions of a pound in the drivetrain when usually much more can be saved with an efficiently designed manipulator. Remember to design the robot as a whole and not just each part independently.

A thought that occurs when reading this: the drive-train is one of the only truly well-understood systems on an FRC robot (I think) because every year every robot needs a drive train. Repetition and redesign of drivetrains over the seasons characterizes the the required durability/strength/requirements very well. This allows the drive train to be thoroughly analyzed and designed well over years through many smaller design tweaks, as compared to a manipulator or game-specific feature that must be developed, analyzed, and optimized in weeks.

[Marc S.]

I don't know much about how you build your robots but making everything in 1/16 wall tubing instead of 1/8 will save a lot of weight and time(if you pocket 1/8). It is also stronger than pocketed 1/8 wall tubing. You can save a lot also if you use aluminum rivets instead of bolts whenever possible.Smaller wheels and custom gearboxes can save weight if done correctly(if you are unsuccessful in designing your own just copy our 2010/2011 gearboxes/drivetrain(link below)).

[Ninja_Bait]

Design it to be underweight. That's why they give us CAD!