Over weight robot
 

We now have 130lbs on our robot and have just kept the stric basic(2 arms, shooter). We don't know where to cut that extra 10 lbs.

Re: Over weight robot
 

What material is your robot made out of?

Also are you weighing your robot with bumbers and/or battery in? If you are take them off and you will be fine.

Re: Over weight robot
 

We took out the bumper and battery but we still at 130lbs plz help me :(:confused:.Here's some photo

Re: Over weight robot
 

well you can start drilling hole,and what mr EricLeifermann said what type of metal or material are you using, and if you have your bumpers and battery on, just remove them and you will be good

Re: Over weight robot
 

Bumper and battery are already out in the 130lbs. We are only using thin metal

Re: Over weight robot
 

well i could say if you just want to shoot, remove the arms ( if the arms are used for climbing), or if you want to climb and play defense, than remove your shooter. it which ever way you guys want to go

Re: Over weight robot
 

My first thought is to put some lightning holes in your hopper and shooter chutes, you don't need a solid piece of metal there. Its not going to get you 10 pounds but its a start.

Also look at how many bolts and the size of bolts you are using. Do you really need what looks like 3 1/4-20 bolts to hold up 1 PVC air tank?

Re: Over weight robot
 

Since you are currently 10lbs over drilling holes is going to be difficult thats a lot of holes. I dont know if there is even room to drill that many holes from your pictures.
I would look over what materials your using, are you using a 1/2'' plate where something much smaller could be use?
Like posted above make sure your battery and bumpers weren't included in that weight.

Re: Over weight robot
 

Last year, we lost about 4 lbs drilling out all the holes we weren't using on the kit frame. That's a start. It looks like your shooter is plywood lined with (1/8"?) aluminium plate. Drill holes into anything that doesn't contact the frisbee. You can easily shed 10 lbs with just drilling holes, don't do anything drastic.

Re: Over weight robot
 

You could replace a lot of you nuts and bolts with lightweight rivets. I can't see much of your pneumatic system, but if you have a lot of brass you should replace it with more plastic fittings and tubes. If your shooter has an adjustable height, you may want to consider fixing it to one position and adjusting the flywheel speed to control disk trajectory.

In the future, your tower probably doesn't need to be as strong as you made it this year. Judging by the pictures you posted, Your tower seems to be made of the same type of stock as your drivetrain, which is overkill.

Re: Over weight robot
 

Our arms are pretty heavy 7lbs each. In this short time we cant get smaller piston.

Re: Over weight robot
 

As said before, start by taking metal out of your feeder chute. You only need rails along the outside edges to hold the frisbees, keeping a pair of rails 2" wide while taking out sections in the middle will help. Same goes for the piece of plywood on your shooter. There is a lot of material and weight you don't need, especially in that plywood seeing as how it is covered in a sheet of metal for the frisbee to slide against.

Look at hogging out holes in the inner frame rails. You need strength on the other rail (that forms the perimeter of the chassis) to take hits from other robots, but the inner rails that support the inside of the wheels don't take near as much force. You could place many large holes in the vertical span of those channels and sacrifice little strength.

It's hard to tell from the photo, but how thick is your electronics platform?

Hardware is another place. I see a couple frame joints that have 3 bolts per leg. Take out the third bolt on each leg and if it is still stiff enough, cut off the excess length from the joint (where the third bolt would have resided).

Re: Over weight robot
 

You could also try replacing the CIMs in your shooter with something smaller like a Bag of MiniCim. It won't get you the 10 lbs, but it will help.

Re: Over weight robot
 

Have you checked this out?

Re: Over weight robot
 

Thank you, we have figured out the stuff to do for reducing the weight. We are taking out the manifold and the compressor plus some holes and cut out some piece. Queston: will we have enough air

Re: Over weight robot
 

Did you release your compressed air before weighing? That can also make a noticeable difference.

Re: Over weight robot
 

drill anything not structural and if that doesn't help any drill more holes between those holes also look for anything not entirely necessarily and see if can removed

so in short drill holes drill holes and drill more holes

Re: Over weight robot
 

Depending on when your regional is, you have time to order lighter ones now that you can drop in during practice day of your event. You also have the withholding allowance....

Re: Over weight robot
 

This is a bit of out an out there idea but you can replace the AM kit frame corner brackets with 1/8 plate gussets. EX: http://www.chiefdelphi.com/media/photos/38516 And use rivets instead of bolts.

Edit: http://www.chiefdelphi.com/media/photos/38390 cad files are in this.

Re: Over weight robot
 

I know you guys are short on weight, but are your accumulators plastic?

If they are, check this out...

It may be a good idea to keep the plastic accumulators, but please see the risk involved with it.

Re: Over weight robot
 

Calculate the mass of the holes before you drill any. Use the volume of a cylindrical hole times the density of the material you're thinking of drilling. This should only take a few minutes to estimate.

Additionally, some cost-benefit analysis of your mechanisms and drilled holes is in order. Are you better of by sacrificing a mechanism and just getting the robot finished, or by taking the next day or so to drill holes in things?

And this goes without saying: everyone participating in your decision must understand the weight limits in the rules.

Re: Over weight robot
 

Oh also, make sure your scale isn't to blame. Get a student that knows her/his weight to stand on it to check or object. You never know!

Re: Over weight robot
 

Additionally, make sure you are using a scale that goes up in small increments.

Re: Over weight robot
 

Enough air for what? If you have 2 plastic tanks and one cylinder like in the photo, probably yes, for one time. If you have 2 cylinders and others, then maybe not. TRY IT AND SEE.

Re: Over weight robot
 

We were very overweight, so we took off our shooter! :ahh: It wasn't working that well, and we were easily able to turn our disc lifter into a level 1 dumper, which may even score more points than the level 3 shooter, and we still have our climber.

Re: Over weight robot
 

Holes Help. We lost 3 lbs last night. Do you have Aluminum gears in your gear boxes? That can be .4-.8 lbs depending on gear boxes.Do you have the small compressor? Do you need to motors on your shooter? How many drive sims? If 4 do you really need 4? Are you sure about your scale? Are you picking up off the floor? Do you have to? Seems like we have a fat robot every year usually don't name him until he is under. 119.9 is all it takes. Good luck.

Re: Over weight robot
 

Try replacing a compressor with a mini compressor, use a smaller c-Rio (we normally use the 4-block one), attach electronics to polycarbonate and Velcro them on.

Re: Over weight robot
 

I disagree; 10 pounds worth of holes is very drastic. We've never been able to lose more than 2 lbs just by swiss-cheesing. Since some of the materials in the pictures look like they are overly heavy, maybe the holes could add up to 4 or 5 pounds.

I would look for structural parts that don't need to be so heavy-duty. Such as C-channel or 80-20 that could be replaced with angle bar, or solid 1/4" plastic or plywood that could be thinner or corrugated.

Re: Over weight robot
 

Remake your shooter with lighter materials. Last year we were 20 pounds over we drilled 1023 holes and only lost 8 pounds. The bulk of our weight loss came from switching to lighter ,materials. I recommend you do the same

Re: Over weight robot
 

10 pounds is a lot to lose, but you can do it. Remember that you don't need to lose it all at once, small cuts add up!

First, think of how much you actually need to run your pneumatics, we have used precharged in the past and as long as you don't have a leak it works well. I would recommend taking off the compressor before removing airtanks, it is heavier and less necessary. If you are using a full sized compressor, you could start by switching to the mini one, that will save you about 2 pounds. If you have the mini one and you take it off that will be about the same.

Swiss cheese is good. Find places that you can drill holes or enlarge ones that are not critical or in use. This won't do a ton, but you could probably get 3-4 pounds out of it if you really stretch it. I would say that 3 is a reasonable goal.

Look at all of your bolts. Find which ones are extraneous and take them out. Like the post above said, you probably don't need 3 1/4-20's to hold up the 1/2 pound airtank. 2 would probably be sufficient, even 1. Heck, you could probably get by with zipties for it. That's what we are using. Find all the bolts that extend far past the nuts holding them on. switch them to the smallest possible size that you can use while still going through the nut. This could add up to about 2 pounds depending on how much you guys take out.

Find material that you don't need and remove it. This is basically just drilling holes but bigger. if you have a full plate that a frisbee will slide on, you really only need the ends, take out the middle. When possible, try using 1/16" metal instead of 1/8". It's tough to tell from the picture but this might be able to get another 2 pounds for you guys.

You probably won't want to do this, but you could also find electrical wires that are too long and shorten them to just what you need. This will cut down a pound or two and eliminate any rat's nest you might have.

As a last resort, fill your air tanks with helium before weigh in ;)

Good luck!!!

Re: Over weight robot
 

A few things:
-Replace all of the sheet metal with similar thickness polycarbonate.
-I can't see your battery mount, but based around the way the bot is built, it's probably overbuilt, but easy to modify
-Drop all the clips that hold in the pneumatic tanks and use 3-4 zipties.

Best of luck!

Re: Over weight robot
 

Hmmm this is a problem. So the first thing I would do is replace your shooter's "runway" with two strips of metal. That will take out a very large amount of weight. That huge piece of plywood has to weigh at least 4 pounds so I would go to a hardware store (Menards or Lowes should have it) and get a piece of 1/8 inch polycarbonate to replace it) Another step is to remove any unnecessary cross-braces. You should also open up unused holes (and add new ones) in the KOP frame members all over your robot (you have a lot of those pieces and they're pretty heavy). Try to eliminate some fasteners (they add a large amount weight) if you have access to a welder then I would recommend welding parts that you don't need to disassemble, if not then you might try rivets. Also, 80-20 adds a ridiculous amount of weight so if you have any (I can't really tell from the picture) I would try replacing it with angle or something. Once again, I would drill LOTS and LOTS of holes, every little bit helps. If you do all of this and it's still not enough, take two drive motors off (if you have four). If worse comes to worse then you'll have to take a mechanism off :( .

Re: Over weight robot
 

Please realize that this was a user error. There is no way that that tank burst by itself. There is nothing wrong with plastic tanks. Most likely the fittings on the tank were over tightened or it was dropped. Please try not to cause panic and bias towards a product because of one team's mistakes.

Re: Over weight robot
 

It looks like you have a lot of fasteners on your robot. If they are stainless steel or steel. if they are you could replace a lot of those with nylock or aluminum.
Hope this post helps.
:)

Re: Over weight robot
 

Our robot also has a weight issue... How strictly is the 120 pound rule enforced? :ahh:

Re: Over weight robot
 

It's a rule in the Game Manual. If you don't meet the rule, your robot is illegal and thus can't compete. And yes, all robots are weighed, at each competition.

Re: Over weight robot
 

You have got to be kidding me.... How heavily enforced is the bag and tag rule?

Re: Over weight robot
 

It is also a rule...it doesn't matter if it is enforced heavily or not. What matters is that it is an official FIRST rule, which all teams should follow. If you break the rule, your robot is illegal. All other teams are stopping work on their robot today...why should you be an exception?

Re: Over weight robot
 

we were just making sure.

time to swiss cheese our robot.

Re: Over weight robot
 

You should actually aim to bring your robot in a few pounds under 120 so that you can make minor modifications at the competition. The 120 pound limit is strictly enforced and you can be reinspected at any point.

Yeah, I know... that advice really helps now, doesn't it?

If you have four CIMs in your drivetrain, you can solve most of your problem just by getting rid of two of them. Yes it will affect your performance... but perhaps not by as much as you fear.

I've found that replacing all the steel screws holding the electronics down with nylon screws can shave about a pound.

The best weight loss program I've seen dropped 30lbs from a robot on Thursday, at an event. We've done ten or fifteen pounds, but it took us a weekend of build time.

One thing you might want to consider is rebuilding one of your components out of lighter weight materials. You can do this as part of your "withholding" limit. Then you could unbolt your current "heavy" unit and replace it with the "lighter" unit at the event...



Jason

Re: Over weight robot
 

I removed 8 lbs of redundant and oversized hardware from a robot once. Remove large screws that aren't needed, replace screws holding on light components and other items with zip ties, and cut down pieces of aluminum that have excess length that aren't holding anything. Holes only go so far...