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-   -   How much does your robot weigh? (http://www.chiefdelphi.com/forums/showthread.php?t=102188)

Savvy578 23-02-2012 00:16

Re: How much does your robot weigh?
 
Our robot weighs anywhere from 112-117. The scale we had was being weird and weight exponentially...

~Cory~ 23-02-2012 00:22

Re: How much does your robot weigh?
 
119.5 on two different scales. :ahh:

Dr Theta 23-02-2012 02:17

Re: How much does your robot weigh?
 
102 as of right now. We're planning some iteration on a few components, so we'll see at comp. We'll definitely be under 120 though.

Mk.32 23-02-2012 02:41

Re: How much does your robot weigh?
 
Quote:

Originally Posted by quinxorin (Post 1132476)
My team's robot is, to my absolute amzement, 110.240 lbs. (Yes, fancy scale). We're always overweight; this year, we didn't swiss cheese; we reinforced. It was amazing!

What kind of scale is that?

RRLedford 23-02-2012 02:46

Re: How much does your robot weigh?
 
We are well under 100 lbs, but we need to bulk all the way up to 120 lbs.
We are adding about 25 lbs of ballast weight to out far right side toward front.
Why? We drive up the bridge with most of our width hanging off the left side of the bridge and leaving room for normal bots to still pass by us on the bridge. Hopefully this makes the 3-bot balance easier with none of us protruding near the ends. With most of the robot overhanging the side rail, we really need a lot of weight on the far right just to have enough traction on the 2 wheels (of 6-wheel tank drive) that remain in good contact with bridge to get us up the slope. Lots of slipping and spinning wheels right now, but we can balance in 3 seconds from first wheel up on the bridge.

-Dick Ledford

Koko Ed 23-02-2012 02:56

Re: How much does your robot weigh?
 
116 pounds (most likely 118 when the signage is added at FLR).

ttakashima 23-02-2012 03:02

Re: How much does your robot weigh?
 
We are at 122.5 lbs. We kept the shooter back, it Currently weighs 21lbs which in my opinion is very heavy. We have many holes to drill! We also still need to add our 2lb side plates at the comp with our sponsor logos!:eek:

ThirteenOfTwo 23-02-2012 03:08

Re: How much does your robot weigh?
 
103 when we weighed without the wiring (but with electronics like CRIO/radio/jags), 108 when we put expected wiring materials on the scale too. Sixteen-pound withheld intake and eleven-pound withheld scoring mechanism leave about 80 lbs in the bag right now. At least eight of the withheld pounds come from COTS gearboxes and motors which will be brought to competition not as a part of the weight allowance.

Cal578 23-02-2012 10:23

Re: How much does your robot weigh?
 
We were at 119 lb with a couple days to go. Since the scale didn't seem to be quite accurate, and we can't be 100% sure that our manual calibration is perfect, being that close to the 120 lb limit made us a little nervous. Even if we believed our scale was perfect, it may not be the same as the one used by inspectors at competition, and we can't argue with their scale. So, we worked on a few things to give us some safety margin.

Many people talk about the "swiss cheese diet". Here are some points to consider:
  1. Drilling holes shouldn't be your first option. We changed to a lighter sprocket, and made a lighter mount for the camera. These were engineering improvements, in addition to saving weight.
  2. It takes a lot of holes in plastic to make any difference in weight, and that often compromises strength before much weight is shed. Target metal, especially thick items, first.
  3. You can remove weight from any part of the main robot to get under the limit, but the location of the removed weight can impact performance. Removing weight up high makes your robot more stable and easier to balance. Removing weight down low can make things worse.
  4. If you have decoration like lights, they count against the weight limit. We have some cool lights that everyone likes, but we had to make the decision that if we're overweight at competition, lights are the first thing to remove (I really hope we don't have to, they look too good). You might be tempted to remove panels that display sponsors, but remember that [R04] requires displaying school and sponsors during competition (plus, it's just right).

Good luck, everyone!

artdutra04 23-02-2012 11:40

Re: How much does your robot weigh?
 
Quote:

Originally Posted by Cal578 (Post 1133299)
[*]It takes a lot of holes in plastic to make any difference in weight, and that often compromises strength before much weight is shed. Target metal, especially thick items, first.

Don't be so quick to immediately discredit lightening plastic components; if the plastic part is large enough, the weight savings become valuable. If you have sheets of Lexan/polycarbonate on your robot, these add up almost deceptively quick in the weight department.

For example, a 24"x36" sheet of 1/16" polycarbonate weighs in at just under 2.4 lbs; the same size panel from 1/8" polycarbonate weighs in at about 4.75 lbs (which is about the same weight as the older Thomas air compressor).

Be warned through: while it is possible to use large hole saws (2-3" diameter) in sheets of Lexan, it's not the easiest thing to do in the pits. It's much easier ahead of time to only use the thinnest possible Lexan.

Cal578 23-02-2012 12:02

Re: How much does your robot weigh?
 
Quote:

Originally Posted by artdutra04 (Post 1133357)
Don't be so quick to immediately discredit lightening plastic components; if the plastic part is large enough, the weight savings become valuable.

I'm not discrediting it; I'm actually agreeing with what you just said. It would take a very large piece of polycarbonate to make a good target for weight savings, and then you need to put lots of holes in it to make a difference. If you have large metal pieces on your robot (sprockets, plates, mounts), you can get more weight savings with fewer, or smaller, holes. I've seen several teams (including mine, four years ago) drill a bunch of holes, get reweighed, and find that they hardly made a difference.

MrForbes 23-02-2012 12:10

Re: How much does your robot weigh?
 
We took about two pounds of Lexan off our shooter...we didn't cut holes in it, we just cut off the excess material that wasn't needed.

As usual, you have to keep weigh in mind all thru the design and build process. If you do this, you shouldn't have a weight problem. We have a really heavy steel chassis, but we're still underweight, because we were pretty careful to use mostly only light materials on the "upper" parts of the robot.

Garret 23-02-2012 12:36

Re: How much does your robot weigh?
 
Without the motherboard for controlling the camera our robot came in at 105 lbs. Very surprising for the amount of stuff on the robot this year.

Ekcrbe 23-02-2012 22:53

Re: How much does your robot weigh?
 
Quote:

Originally Posted by CalTran (Post 1122164)
Well, 15ish lbs, give or take

The last battery I checked that we had was 12.55 lbs, but I haven't averaged any more.

gracie. 23-02-2012 23:13

Re: How much does your robot weigh?
 
Our final weight before bag & tag was 111 lbs. With the extra bumper and battery weight to lower our center of gravity, we're not too worried to be under the weight limit. If you're over, the universal advice is to start drilling holes. We've done it in the past, and I'm sure we'll do it again. Start with lightweight stuff in the first place, and if that fails, bring large drill bits.

JamesCH95 24-02-2012 08:04

Re: How much does your robot weigh?
 
Quote:

Originally Posted by Ekcrbe (Post 1133817)
The last battery I checked that we had was 12.55 lbs, but I haven't averaged any more.

FWIW 95's rule of thumb, from the old-school days when we weighed robots with batteries, was 13lbs/battery with the typical-length 6awg leads. Some batteries could be up to 2lbs less than this if they were older.

I definitely agree that 15lbs is a a few lbs too generous for battery weight.

kendra21093 24-02-2012 09:51

Re: How much does your robot weigh?
 
121.2 LBS...WHYYYY??????? D:

reymac 25-02-2012 19:52

Re: How much does your robot weigh?
 
We are at 105 pounds. We may consider adding weight to our robot depending on its performance in practice rounds

stundt1 25-02-2012 19:56

Re: How much does your robot weigh?
 
We are around 120 pounds. Our scale wasnt calibrated correctly so we are really unsure but we should be around the 118-120 pound area.

If we are over our cathodes and side panels will the first to come off. Though if we are under weight we decided we might add a second camera to assist the operator and driver.

peter1626 25-02-2012 20:10

Re: How much does your robot weigh?
 
Three days before the deadline we finally got a hold of a scale... We were 139, after redesigning the entire front of the robot and the pickup system then we removed the protective 1/4" Plexiglass and replacing it with 1/8" with holes we were 118

Grim Tuesday 25-02-2012 21:23

Re: How much does your robot weigh?
 
Just a note to Fingerlakes teams who are barely within the weight limit: Operation Bonde is in effect, and the new router weighs about .2 lbs more than the old one, though the mounting geometry is the same. Just so you know.

Garrett.d.w 25-02-2012 21:29

Re: How much does your robot weigh?
 
120

and an extra .2

Though that will be easily shed after arming a freshman with a hole saw :P

cgmv123 25-02-2012 21:58

Re: How much does your robot weigh?
 
Quote:

Originally Posted by Grim Tuesday (Post 1134868)
Just a note to Fingerlakes teams who are barely within the weight limit: Operation Bonde is in effect, and the new router weighs about .2 lbs more than the old one, though the mounting geometry is the same. Just so you know.

The Bondé router is exempt from inspection. If you pass with the DAP, they can't weigh you with the Bondé router and fail you.

Quote:

Originally Posted by Team Update 2012-01-20
Teams will still go through inspection with their DAP-1522 (to meet size and weight parameters); the DIR-825 will not be subjected to inspection.



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