View Full Version : How much over did you weigh?!?
Lets spill it. We are a whopping 23 pounds over and are desperately figure ways to cut weight without cutting fuctionality. How about you?
Carolyn Duncan
16-02-2002, 21:54
Well, team 86 was about 15 lbs over weight so we started drilling.... A few blisters and many hours later we are right on! Hopefully the scale we used and the scale at comps are weighing the same...
116 started out at 165+:eek:
30 lbs later...:D
8lbs left to go...:(
us canadians were sooo close when we went to weigh our bot having no idea of the weight until today. It turned out to be 131 lbs but we wanted to be 5 lbs under soo we put our bot on a diet today and a strict exercise routine and we lost about 10 lbs so we have no problems. I hope you guys can manage to fix your bots weight. I guess i will be seeing a lot of swiss cheese at the comps. well best of luck.
P.S. how exactly do they measue the size of the robot. i recall from our last robotics comp (canada first competition) they put a crate over the bot to see if it would fit in those dimensions. is it similar in FIRST.
Yes, you are put inside a box. At least, they did at VCU last year.
You people that are over 30, tell how much you're going to have to sacrifice, ability wise.
Stephanie
17-02-2002, 03:04
hah, 668 started out at 20 lbs over. we've been swiss cheesin' and jigsawin', but our scale seems very unreliable. we weighed it a couple different ways tonight, and the first few times it read 10 lbs over, and the second few times it read 4 lbs under:rolleyes:
if you ned a really accurate scale, most vets have large digital scales that are very accurate that is how we weigh our bot
Kris Verdeyen
17-02-2002, 10:01
118's first weigh-in was at 165+ as well. But that was primarily due to our goal to get up and running as soon as possible. We had not yet lightened our 1/4 thick aluminum top plate (30X33 or so) and our 26' diameter turret. Here's a helpful hint, btw: when lightening, use a mill - you can get more weight faster than a drill press, it looks better, and if you don't punch all the way through, you can keep a large portion of the original strength of the metal. So now we have about seven more pounds to lose. The only loss of functionality might be that our turret is only 25", and we might have to go to an aluminum chassis.
My team (639) was so heavy we had to cut 2 of our wheels off. And i thought 4 had to touch the ground at all times, boy was i wrong.
Greg
Joseph F
17-02-2002, 21:42
We (team 506) weighed are robot two days ago and it was 127... however we still had roughly 20lbs of stuff to add to it, if not more. We totally redesigned one of our systems, and altered some big parts on other systems. Without drilling a single hole we dropped 20lbs, and gained effecinecy without loosing functionality. :-)
One option that we have been kicking around is the airport. The baggage checkin has a scale large enough. THe only thing is calling and getting it okayed...
We may just try a local vet, it closer by 15 minutes too.
Luckily, one of the student's mother is a vet and the clinic is just down the street. Man, that was a cold ride in the back of the truck. Oh yeah, we're down to maybe 3 pounds over.
You can go to Small Parts and purchase an assortment of various sized holes to place on your robot for weight reduction. They are expensive - only the very rich teams can afford them - but it is convenient to be able to move the holes around until you get them just right. We had a box of them around, but unfortunately I mixed up all the sizes in one box and the little ones fell through the big hole and I never found them again.
We tried running the compressor on helium, but the robot had such a squeaky little voice we couldn't stand it.
Permanent magnets are allowed in any amount. You could try aligning their fields against the earth's magentic field to generate some lift. Of course, your 'bot will have to be able to handle directional derivatives, and convolution integrals aren't on the additional hardware list. You might be better off working in the frequency domain.
Next year Exide is coming out with a battery that uses massless neutrinos. Getting rid of that heavy box full of electrons will be a big help - just not this year.
There may be a topological way out, though. If you start with a two-dimensional Moebius strip, and move up to the three-dimensional Klein Bottle, there should be some way to take the next step to a four-dimensional construct (let's call it a "Kamen Manifold") that would get rid of the mass entirely. Then you can work with all kinds of neat things, like PVC pipe with an OD smaller than the ID so that the inside is on the outside.
By the way, how strictly do you think the ref's are going to enforce L'Hopital's Rule this year? I mean, you have to set SOME limits...............
Chris Hibner
18-02-2002, 09:46
We weighed in 17 lb over weight, which is funny because last year at first weight-in we were 17 lb over as well.
We ended up losing 30 lb without really losing any functionality this year so we can now add in the extra functionality that we wanted to add.
By the way, look for pictures soon.
-Chris
gniticxe
18-02-2002, 10:11
At our most recent weigh-in, we were 7 lbs over. Considering everything had already been 'lightened,' we were faced with a tough decision. We ended up having to sacrifice a bit of functionality to get us under, but things may change today (mmm hole saws....) and we may be able to regain the part.
~another cryptic post trying not to reveal our strategy ;)
good luck everybody
Kris Verdeyen
18-02-2002, 18:46
Originally posted by Leo M
There may be a topological way out, though. If you start with a two-dimensional Moebius strip, and move up to the three-dimensional Klein Bottle, there should be some way to take the next step to a four-dimensional construct (let's call it a "Kamen Manifold") that would get rid of the mass entirely. Then you can work with all kinds of neat things, like PVC pipe with an OD smaller than the ID so that the inside is on the outside.
This is addressed in the rules:
M1. All robots must be entirely contained inside a 36"x30"x60"x0" box.
So you're out of luck.
:)
It was amazing -- we didn't measure anything as we went, and when we finally finished, we put it on the scale and it weighed 129.3. Talk about luck!
quote:
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Originally posted by Leo M
There may be a topological way out, though. If you start with a two-dimensional Moebius strip, and move up to the three-dimensional Klein Bottle, there should be some way to take the next step to a four-dimensional construct (let's call it a "Kamen Manifold") that would get rid of the mass entirely. Then you can work with all kinds of neat things, like PVC pipe with an OD smaller than the ID so that the inside is on the outside.
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This is addressed in the rules:
M1. All robots must be entirely contained inside a 36"x30"x60"x0" box.
So you're out of luck.
Not really - if you get the parameters right, the entire universe is inside the outside, because the outside is on the inside. But then, there will be nothing outside the box besides management consultants, thinking....................................
Curtis Williams
19-02-2002, 07:30
We ended up about 8 pounds overweight with our original design. Goodbye steel.
Made weight without sacrficing functionality!
w00t!
Monday morning we celebrated our robot finally working. Monday afternoon we weighed in at 150. Oops. Tuesday at 1 o'clock am I finished drilling my 200-somethingth hole. I don't know how we did it, but we cut around 21 lbs. Unfortunately about 10% of our functionality had to be sacrificed, mainly including a piece that wasn't reallly working anyways and our shielding. Hopefully we're enough under to put on some lighter (acrylic?) shields to protect our innards after we check our weight at the regionals.
Kit Gerhart
19-02-2002, 22:49
Originally posted by Brett W
P.S. how exactly do they measue the size of the robot. i recall from our last robotics comp (canada first competition) they put a crate over the bot to see if it would fit in those dimensions. is it similar in FIRST.
They have you put your machine in a Lexan box with one side missing. The robot has to fit without your having to push too hard, and without leaving deep scratches in the box.
AHhaa. Our robot initally (we thought) was 15 lb underweight. But we learned that our 10 year old bathroom scale is a tad bit off.... about 10 lb off ahahaha
Luckily, when we got a better scale and got it's accurate weight, it was only around 2 lb overweight. So we but off the ends of some bolts and took off a sheet of Lexan and it was fine. Did you know that Lexan about 4"x28" weights in about 1 lb?
We are happy we didn't have to swiss cheese this year. :D
We thought we were done Monday morning. The robot was driving nicely, everything was great. Then, we went to weigh it and ended up being 150lbs.
after about 10 hours of mad drilling/punching holes brought it down under 130lbs :)
junkyarddawg
23-02-2002, 11:53
Although in previous years, we completely wore out hole cutters, this year we weighed in at 123 lbs. with everything we wanted on the machine and no real attention given to weight loss. However, we do pay close attention to structure as opposed to materials.
DaBruteForceGuy
23-02-2002, 12:48
we were so overweight that we needed to shred 29lbs with three days left!!!
believe it or not we did it! thopugh it took us a whole day and night we chopped off 29+, that is with about 400 holes and knocking huge chunks of alluminium off our drive train. it was a mess but we did it.
one problem though.. WE FORGOT ABOUT PROTECTION! so wednesday morning we had to of added 5lbs to our overall weight
junkyarddawg
23-02-2002, 12:56
Lexan, while flexible, makes a great protective shield.
DaBruteForceGuy
23-02-2002, 13:09
Lexan, while flexible, makes a great protective shield.
we used lexan, but there is one problem.....
it weighs a whole lot!
besides it was 1/4inch so it also added to our structural integrity as well.
RicNic_team930
02-03-2002, 12:38
we drilled holes from the begining so at our final weigh in we were right there at 130 but we needed to drop a little incase the scales are different. our sponsor that donated warehouse and machine use had a scale for weighing heavy objects. Thanks Item midwest.:)
We went to a Mailboxes Etc to weigh ED
Mark Hamilton
02-03-2002, 22:34
The fact that some of you designed machines in which you were able to cut 30 pnds worth of holes out of really scares me. We drilled all the holes we could afford and still only lost about 5 pds. Are you people making your robots out of large flat sheets of 1" thick steel or something?????
We cut 30, but who ever said we did it with holes??
We ended up cutting out the whole pneumatics system...
Plus, PVC is heavy, so, put holes in it and where you can, replace it with something like aluminum angle....
Use a smaller chain....
Originally posted by AdamT
We cut 30, but who ever said we did it with holes??
We ended up cutting out the whole pneumatics system...
Plus, PVC is heavy, so, put holes in it and where you can, replace it with something like aluminum angle....
Use a smaller chain....
instead of pvc you we of looked into thin wall alunimum conduent ....its both light wieght and strong at the same time ..it cut out 3 pounds off of are overall weight ...:D
I had thought about that, but it doesn't seem to good against balls...oh well.
I totaly agree in that aspect that the balls would slip ...we simply used a mess belt over them (the ones in small parts) to create friction ....it worked out great because the material was really tacky .....try it out on your pvc rollors. it might work great for ya !!
The more I think about it, the more i think that conduit would work for us. We don't actually make contact with the balls...we've probably taken out about the same amount of weight anyways. Thanks!
Originally posted by AdamT
We don't actually make contact with the balls...!
Umm...how do you pick them up if you don't touch them?
Telpathy is really cool, and prolly with in the rules....:D
Silly me,
We don't make contact with the ROLLERs...we are using a nice belt from McMaster the works wonders. I thik it takes less then three seconds from the time the ball hits the front roller to the time it hits the bottom of the basket. Lets hope it works the whole time...
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