Weight of Trailers

FIRST General Forum
1

So, what is the exact weight of the trailers? I’ve heard that they’re 20-25 pounds or so but an exact answer would be appreciated. I realize that plywood does vary in density a little but withing half a pound overall would be an awesome estimate.

thank you, Vivek

2

I dont know. My one advisor said they only weigh about 15 lbs. But I have been hearing different things everywhere.

3

We would like to know that too.

4

No promises but I’ll try and calculate it using inventor by setting mass properties for the model that I obtained for the trailer. I suspect an actual weigh in would be more accurate.

thanks, Vivek

5

How about the tongue weight?

6

I’ve built parts for six trailers for the Peachtree Regional Kick-off and Scrimmage and have assembled two of them completely. I used the actual plans that FIRST uses to make the official trailers. I built ours exactly to spec except that I used Sono tube for the target rather than the HDPE. In spite of this, I have the HDPE and have weighed the trailer and appropriate amount of HDPE in place of the Sono tube.

Using bathroom scales, I find that the trailer is 35-36 pounds.

I haven’t checked the tongue weight yet, but it is slightly tongue heavy. The CG is pretty high on these so a slight change in height of the tongue will change the tongue weight significantly. That shouldn’t be a problem since the tongue should always be the same height above the floor.

I’ll try to check the tongue weight in a day or so when I assemble another one.

I’ve been reading posts and notice that not enough attention has been paid to the problems that the trailer will cause. With robot, bumpers, battery and a 35 pound trailer, plus some moon rocks you are up around 180-190 pounds!

Retired Starman
Mentor
Team 1648
Atlanta, GA

7

Just making sure…and I really appreciate the information, I do understand how much the trailer will effect vehicle dynamics…you used alumalite and coroplast for these trailers and not plywood? They are both very lightweight materials.

Thanks again,

Greg

8

I think the trailers are around 40 pounds or so plus the weight of the balls.

9

Retired Starman (or anyone else who had built their trailers exactly to FIRST’s specs),

Can you please measure the weight of the trailer without and with balls loaded on scales accurate to the .1 lbs?

The mass of the trailer is REALLY going to make a difference in driving this year.

10

We should be done with our trailer tonight or tomorrow according to all the FIRST specs. I will post the weight as soon as possible.

11

does anyone have a density for the alumalite? I’m having a hard time finding it.

12

I’ll answer my own question. - Density = .023 lbm/in³.
I get the bottom plate of the assembly to weigh ~ 3.5 lbs.

My CAD assembly is still needed bumpers and fasteners, so I won’t mention the hypothetical weight yet.

13

so wat are the specs to the trailer exactly?

14

See the Official [i]FIRST Drawings on the FIRST web site.

15

35 balls weighs 17.5 lbs.

16

Do you find out the tongue weight?

17

wow 35 pounds is a lot of weight on the back of the robot. How much would you figure the trailer weight is when its full with balls? they dont seem that heavy but I know that the weight adds up quick.

18

I’ll have a tongue weight sometime this Saturday after I finish another trailer. I don’t have access to a scale accurate to 0.1 lb that I can put one of these things on. I may be able to get that for you next week. These things are pretty big and unless you have a large platform scale, it is very difficult to weigh them. Thirty-five pounds is the design weight and that is very close to what I got on my bathroom scales. That’s built with Alumilite and the Coraplast or whatever that corrugated plastic is called, just like the plans called for. I can’t tell you what the weight is full of balls because I don’t know how many balls you can get in there. I’ve heard of one team that loaded over 80 of them in one trailer, but I haven’t confirmed that. Let’s face it, if someone has scored 80 balls in your trailer, you aren’t going to win that match anyway!

Retired Starman
Mentor
Team 1648

19

Our trailer was made to all the FIRST specs and weighs 41.8 lbs (45.0 with our 6 orbit balls in it).

I forgot my camera today, but I will try to post a picture ASAP if you would like.

Hope that helps,
Molly
CIA Team 291

20

Our trailer was made to all the FIRST specs and weighs 41.8 lbs (45.0 with our 6 orbit balls in it).

I forgot my camera today, but I will try to post a picture ASAP if you would like.

Hope that helps,
Molly
CIA Team 291