Weight of Trailers
 

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

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

We would like to know that too.

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

How about the tongue weight?

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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.

Re: Weight of Trailers
 

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.

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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.

Re: Weight of Trailers
 

so wat are the specs to the trailer exactly?

Re: Weight of Trailers
 

See the Official FIRST Drawings on the FIRST web site.

Re: Weight of Trailers
 

35 balls weighs 17.5 lbs.

Re: Weight of Trailers
 

Do you find out the tongue weight?

Re: Weight of Trailers
 

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.

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

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

Re: Weight of Trailers
 

I checked the tongue weight this morning on a trailer built to FIRST competition specifications. I found it to be a little over 5 pounds with the trailer leveled, the way it should be during competition. I think this is a good figure for teams to use.

BetsySpike,

If you built your trailer to competition specifiations rather than team-built specifications and you came out over 40 pounds, we need to talk. Is your trailer built to FIRST specs for the team-built trailer (plywood) or did you use the competition-built trailer (Alumalite and Coroplast)?

The official field elements will be constructed according to plans found here:

http://usfirst.org/community/frc/content.aspx?id=11624

Specifically, look for "Payload Trailer Assembly" Drawing GE-09000. It will refer you to 33 pages of prints to build an official trailer. The ones I built could be used in competition.

There are several differences in the Team-Built (TB) and Competition-Built (CB) trailers that affect the weight.
1. Top and bottom of the TB are plywood as opposed to Alumalite in the CB Trailer.
2. Bumper backs are plywood in the TB and Coroplast in the CB Trailer.
3. Bumper mounts and wheel mounts are wood in the TB trailer, aluminum brackets in the CB trailer.
4. Tongue is a piece of conduit in the TB trailer, steel pin machined to turn in the end of a square aluminum tube for the CB Trailer.
5. Target is an 8 in. diameter HDPE tube in the CB trailer as opposed to a plywood semi-tube for the TB trailer.

Built to Competition Specifications, the trailer comes out about 35 pounds.

Retired Starman
Mentor, Team 1648

Re: Weight of Trailers
 

Whereas the Team plywood version of the trailer is built according to drawings TE-09000.

Thanks for the information, Starman!

Re: Weight of Trailers
 

it says in the updates they are 36 pounds on earth and only 6 on the moon... i ask my team... "why do we care about the weigt on the moon!!! WE aren't going there!!"

Re: Weight of Trailers
 

mostly in the end if you add your robot, your bumpers, and the trailer, its about 180 lbs so its about 40 ish.