Got Weight?
 

(starts talking in infomercial guy's voice) Is you robot overweight, does your team think that they just wasted 6 hard weeks of work. No worries Ill have the perfect solution as soon as i think of one. please help me with any ideas

Re: Got Weight?
 

Step 1: Get Drill
Step 2: Insert 1/2"-1" bit into drill
Step 3: Drill Those Speed Holes!

Re: Got Weight?
 

remove unecessary components that would be cool, but would add weight.
use lighter material (ie: aluminum)...
see news updates...

Re: Got Weight?
 

LIGHTNING HOLES, that's a hint

Re: Got Weight?
 

Make enough holes so you can use your robot as a CHEESE GRATER at the end of the season! :)

:cool: Tomasz Bania :cool:

Re: Got Weight?
 

if you're using a shooter with two wheels, you could try cutting out some of the spokes and putting some cardboard over it so that it would be just as aerodynamic but weigh less.

Re: Got Weight?
 

Holes help. I think in the past 3 days my team has taken 6-7 pounds off of our robot. Get a couple drills ready, they do heat up when run for a long time.

Re: Got Weight?
 

Take the white space out of your program.

Re: Got Weight?
 

Ha.

But getting back to the speed holes, I'll put in the boilerplate: don't be stupid with the swiss cheesing. Poking a bunch of holes in your hopper that was built around the requirement of having a perfectly smooth bottom may come back to bite you in your bottom.

Just be smart about where you poke holes, and you'll be good.

Re: Got Weight?
 

good idea

Re: Got Weight?
 

Switch the air in your tires with helium.

Re: Got Weight?
 

drill one-way holes in your air cylinders.

Then refill your brake light fluid.

And change your muffler bearings.

Re: Got Weight?
 

Don't forget to remove all the comments in your code, and scrape the insulation off all the wiring.

Re: Got Weight?
 

And drill holes in the RC, radio, and camera. ;)

Seriously, though, it looks like we will be underweight...by 2 pounds! :rolleyes:

Re: Got Weight?
 

Use a smaller font in the code.

Also, avoid using entire colons when a semicolon would work just fine.

Re: Got Weight?
 

C'mon now, thats just silly.

Everyone knows the weight of code is really influenced by how many non working sections you have commented out!

Re: Got Weight?
 

Robot liposuction :D

Also try trimming bolts that are at unnecessary lengths, it adds up

Re: Got Weight?
 

Remove three strands from every wire.

But seriously copper is heavy shorten any excess wire runs and service loops.

Also swissing your robot isn't really good for that much weight. You can only get a couple pounds usually.

Thinner lexan and narrower diameter pneumatics are also good tricks if you can.

Re: Got Weight?
 

You'd be surprised with the speed holes. Last year we removed almost 20 pounds from ours, granted we had an 18' telescoping boom made of 1/8 aluminum box tubing, but still, it adds up, every little bit counts. And the thinner lexan is a good point, thinner everything will work really, we cut alot of weight a few years ago by going down 1 size in all the PVC tubing we used.

Also, smaller/less motors if you can, they weigh a bit.

Re: Got Weight?
 

I'll post a picture soon of our robot, and you will see that the back of our robot (specifically the ball catcher, not the hopper) literally looks like a cheese grater!

Re: Got Weight?
 

I was told that we're calling in the Orkin Man to debug our code for us - that should take a good deal of weight out.

You'd be surprised what you can put holes in that willl actually benefit your robot's functionality. I can't comment on speed effects really, but in terms of moving balls around... ;)

Re: Got Weight?
 

There's your problem right there. We only got .2 lbs when we lightened out arm last year, however ours was only 13 feet.

Re: Got Weight?
 

You could replace heavy steel sprockets with lightweight aluminum ones.
That might save a few pounds.

Re: Got Weight?
 

lol...

holes work no matter where you put them.. :) As long as it isnt in a major compenent ...lol

-Pavan

Re: Got Weight?
 

We weighed in this morning at the local fruit packing plant. It was 114 lbs. Our robot is having surgery as we speak. :eek: 114 was too much as we still have things like shields and bracing to install, battery covers, and part of the hopper. Took off 5 lbs by removing a noncritical part and replacing it with something lighter. WOWOWOW. Diet time.

Last years robot was 4 ounces under the 120 limit.

Carolyn Hinckley

Re: Got Weight?
 

Last year I ordered aluminum nuts and bolts for my team. Bolts, nuts and washers are made of steel which is much heavier than aluminum(about 5x as much). Most bolts and nuts also don't take even close to the load necessary to break or bend them. We didn't build our robot with them, but I took an inventory of the major bolt sizes we used and brought boxes of aluminum replacements to the competitions. Whenever we needed to change a part we optimized it with aluminum parts.

I've also heard of team using plastic hardware which is 1/3 the weight of aluminum and I guess 1/15th the weight of steel.

Re: Got Weight?
 

Compressor:
Last year we made a backpack with a compressor and a battery so we could fill the tanks right before each match. It saved us a few pounds.

Structure:
Re-evaluate your structural design. Chances are you have over-engineered some parts. Can they be replaced with thinner materials?

Durable vs. disposable:
Can you replace something that is very durable with something that will last you through a match and can then be replaced? Our team uses 1/16" polycarbonate for shielding our robot. Some pieces survive an entire regional unscathed, other pieces need to be replaced every couple rounds. We could have used thicker polycarb and spent less time replacing stuff, but we get a lot more functionality by having a few extra pounds to work with. Of course, if you go the disposable route, be sure it's easy to replace and you have lots of spares.

Re: Got Weight?
 

While our robot is made of holes, it is important to remember that you need about 40 1" holes in 1/4" Al to cut out a pound of weight.
So get drilling. ;)

Re: Got Weight?
 

Get on your hands and knees with a file.

Re: Got Weight?
 

Advice to stay underweight:

Use ligher materials whenever possible, but use metal for things that have to be more robust, such as turrets, drive, and moving parts.
Use PVC for nonmoving parts, such as bins.
Weigh the parts of your robot, and your robot at each substage of building.
Don't use pneumatics.
Budget your weight and keep to your weight budget.
Remember, design each part with weight in mind. A well-designed, well-built robot should not have to deal with a weight problem.

Advice to get underweight if overwieght:

Make Swiss cheese (something that's already been said way too much)
Don't use more motors than you need.
Keep your frame simple.
Look for lighter alternatives to what you have. This invovles doing a bunch of research.
Remove unnecessary parts

Re: Got Weight?
 

Today we finally got a chance to weigh our robot, and much to our suprise we came in at an alarming 160 lbs. Didn't see that coming.

We weighed it with the battery, though, so we are only about 25 lbs overweight. 8 hours of drilling/punching/crying, we got rid of an excess 15 pounds or so, but we still have a ways to go. We may only have 2 motors for our drivetrain in the end...

Oh well, lesson learned.

Re: Got Weight?
 

Or even nylon sprockets. We've been using them for our drive wheels the past two years. Just be careful about using them in very high torque areas.

Re: Got Weight?
 

One little piece of advice, look at the game footage from recent and try to prioritize what is most important, because if you design the robot and plan for 4 drive motors then only have 2, you might have problems as well as the system itself so look carefully before taking out portions of systems.
Otherwise, drill away as the omni bit is your friend

Re: Got Weight?
 

If you have a lot of lexan on your bot, you may want to invest in a hole saw bit. Example, we had a lot of lexan on our bot...we weighed in at a cool 128 lbs. After removing un needed metal and making our bot very holy, we are down to 89lbs (and fast) :-)

Just remember that structural support is very important. Often you can drill holes as needed, provided you know what you are drilling into.

Good luck!

Re: Got Weight?
 

Last year we were about 20lbs overweight. Its supprizing how little material is really needed for structural stability. We removed 8lbs of aluminum from our arm- boy that was a long night. We also replaced about 5lbs of steel bolts with plastic ones. They really dont come close to reaching their yeild strength.

This year, thanks to keeping track of the weight as we built, were at a cool 90lbs!

Re: Got Weight?
 

thanks but we just had to get lighter materials and now were under

Re: Got Weight?
 

If you are using PVC pipe anywhere, try using ABS instead. We had to replace our PVC pipe rollers with ABS. If we could have found the very thin (say 1/16") ABS drain or vent pipe, we would have used that. There is also electrical conduit that is a foamed core PVC which is quite a bit lighter.

Some of the electrical components and non-stress items can be held on with nylon fasteners.

Steel sprockets can be shaved down quite a bit if you have machining facilities. If not, ask a local community college that has machining courses.

If you are using the kit frame, there's ways you can cut out a lot where the frame rails and joining pieces overlap since it seems to be a bit overkill.

Depending on the nature of the joint, you may be able to use a smaller but stronger bolt. One year, we used 10-32 allen head cap screws to hold our entire frame together rather than 1/4 inch bolts. A good grade of 10-32 is about as strong as a crummy hardeware store 1/4 inch bolt made with soft steel. We prefer grade 5 and grade 8 fasteners. You might be able to have some joints in aluminum welded to reduce the weight of overlapping sections and bolts. You may be able to grind a bit off the tops of bolt heads.

If you are using a converor belt of some sort, perhaps you can punch holes in it. We used some 2 ft wide rubberized cloth conveyor belt, similar to what tou'd see at a grocery checkout but fairly thin. Tough stuff, but very heavy. We sharpened up the end of a piece of small diameter car exhaust tubing and pounded out about 250 holes, cookie-cutter style. Had to use soapy water to get it to cut cleanly, and sharpened often.

Re: Got Weight?
 

Yeah, a little too much weight :D



Swiss Cheesing it.....overtime

Re: Got Weight?
 

We weighed in five lbs over weight, but since we have a lexan tube surrounding our spiral, we will most likely be making it more air than actual material.

Hehehe drills.

For the random comment, anybody see the Strongbad where he drills Strongsads bellybutton? Its under an episode about how the stick got its place/name/something.

Re: Got Weight?
 

... and the comments. Nothing worse than weighty comments!

Re: Got Weight?
 

Since you're pimpin your products again John, in case EO didn't call can you make sure ours get shipped tommorrow? :ahh: :eek: :D
Pete

Re: Got Weight?
 

We are under weight, but we have a very important component to add yet...

I just went through with the mill and took a couple of mounting blocks that were 17 ounces each down to about 5.03 ounces each :)

Looks like I have a lot more to do...

Re: Got Weight?
 

Ours is like 7 pounds underweight, which is good. We decided to use those spare pounds to balance out the robot and help it come off the ramp without tipping (which has happened to us twice).

Re: Got Weight?
 

Hmm... I can't imagine those being strong.

All I can think about is them getting torn to shreds in the middle of a pushing match.

Re: Got Weight?
 

Our team was able to lose 10lbs off the robot in 1 day.. BEAT THAT JENNY CRAGE!

Re: Got Weight?
 

we shaved about 40 lbs in 3 days.....

Re: Got Weight?
 

On the aluminum frame with the 1/4" holes in it, I used a Uni-Bit (one of those stepped-bits with wider rings for each size hole) to drill out EVERY hole to 5/16". We may need to go to 3/8", but for now this has worked.

Also, we drilled out nearly every peice of Lexan on the robot in cool designs and patterns.

Re: Got Weight?
 

For real?

Re: Got Weight?
 

We took off about 20lb in 6 hours on sunday... it was quite the feat, but we learned some interesting things...

Like did you know that it takes 6 2"dia holes in 1/8" lexan to take out 0.1lb?

And that 3 1 1/2" bolts with their washer & nut weigh 0.1lb?

But it takes 50+ 1/2" holes in 1/16" alumnum to take out 0.1lb! Thats a very overworked drillpress!

We took out as much unnecessary support, bolts, lexan, steel plate, etc as we could. Ashley kept track of how much we had lost each half hour, and it was cool to see the giant bucket of parts & hacked off pieces in the end.

Now our poor little robot is all skin and bones!

Re: Got Weight?
 

It's a little to late for this tip I use, but I design my least favorite (aka risky, cute but not worth much, or complicated) components to be massive. That way I have one more excuse to get rid of them.

Re: Got Weight?
 

there is one of these puppies, with even more sizes, at the shop we were working in. If you have to punch a bazillion 2" holes, this is the only way to fly!

Re: Got Weight?
 

Oh yeah, that lift was huge!

Re: Got Weight?
 

if you bring your robot to a place with less gravity hmmm... lets say the moon for example you will be all set and plenty under weight. :yikes:

Re: Got Weight?
 

It was mentioned twice before but my personal favorite tool in the Dremel. That means any screw that is too long gets the axe. Believe it or not, it does help. More so with the longer screws. Then again, our robot is all nuts and bolts so obviously, it would make a difference to us.
(Of course, we also swissed our robot. now we are comfortably under weight =D)

Re: Got Weight?
 

Zip ties are your friends. I can't tell you exactly how much lighter they are, but they sure are much lighter than steel.

We were so concerned about weight, we even used smaller zip ties in areas of little stress. I love zip ties.

Re: Got Weight?
 

Last year all of our speed controllers and electronics were held on soley by zipties. They never gave us any trouble.

Re: Got Weight?
 

An antigravity generator...oh and a drill