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popnbrown
07-04-2014, 14:08
So while I've been on a team that's used crates, I was never involved in the construction of them. I'm also sure rules have changed since 2008, but I've got a few questions.

I'm pretty much following this - http://www.bu.edu/bufirst/files/2011/01/How-To-Build-A-Crate.pdf but just putting the lumber on the inside, so we can paint the outside, and also attaching hinges to make a door so that we can quickly take the robot out.

So my questions:
- Our robot is tiny, but we wanted to include some tools so we don't have to drive down a giant van, is this allowed?
- Also wanted to include batteries (http://frc-manual.usfirst.org/upload/pdfs/2012/12/Shipping_Crate_Construction_v3.0.pdf) they ask us to use the carton packagin, do we just find a box and put it in there with some styrofoam around it? Could someone provide a picture of what these should look like packed?
- I was planning on putting 2 2x4s on the inside of the bottom, so the wheels of the robot were elevated. Any good way to tie the robot down or do we just stuff things around it?

I'll post questions as I come up with them! Thanks in advance.

-Sravan

801DOC
07-04-2014, 14:54
Saravan,

It looks like you are on the right track.

It is my understanding that you can put additional items in your crate as long as it is not over the weight limit or you will get charged.

Also, your idea about hinging the door for ease of robot removal is a good one. My team has a split design that allows us to use the crate for shelving and a workspace in the pits. It helps with uncrating and recrating since the crate stays in our pits.

You can use tiedown straps to hold your robot in place or you can use metal straps that you screw into the 2x4s. I would ensure that the bottom of your robot can take the load of your robot to minimize the possibility of damage.

I hope this helps to answer your questions. If you have any more, feel free to message me directly and I will answer them the best I can.

DOC

Mark McLeod
07-04-2014, 14:57
The FedEx shipping is donated to teams, but please don't go over the 400 lb limit.
While being over 400 lbs will earn you additional charges from the local drayage company that stores your crate (that you will pay and may be willing to absorb), the long distance FedEx portion of it counts against FIRST HQ's allocation and FIRST HQ gets charged at the end of the year for all team FedEx overages beyond the donated shipping max.

You can put what you want in the crate, with proper outside labeling for the batteries as hazardous materials.

We try to block the frame up keeping the wheels from supporting the robot during shipping. Crate drops from loading on/off the truck and being shoved around are better absorbed by the main support frame of the robot.

We add eyelets to the sides around the bottom and midway up the crate to use as tiedown points. Then use wide straps wrapped around the robot bag mid to top points of the robot superstructure that gets tied to the mid-level eyelets. Same around the bottom.

We reinforce the walls of the lower foot or so of the crate on the two forklift ends to better sustain incidental forklift misses. I'd suggest putting the door, especially if it's hinged, on a side the forklift won't use. We've lost a couple of doors to near misses by forklift operators over the years.

Jon Stratis
07-04-2014, 15:07
For securing the robot in the crate, we've always elevated it on some 2x4's (to keep the wheels off the ground and give a solid mount to the frame) and bolted through the robot frame (and bag) into the 2x4. Small holes in the bag for a few screws to secure the robot to the crate aren't a big deal.

This was easier when we have the c-channel KOP frames, but we managed to do something similar this year with the new KOP frame, driving the screws in diagonally through the side of the frame (There are some nice, large holes in the side that work for this) and using some small plates to ensure the frame didn't pull through them.

popnbrown
07-04-2014, 17:05
Also, your idea about hinging the door for ease of robot removal is a good one. My team has a split design that allows us to use the crate for shelving and a workspace in the pits.

I was actually thinking of something similar as I'm drawing crate dimensions instead of working. We desperately need some organization so might as well.

Our robot is 43 lbs, so there's pretty much a very slim chance of going over the limit. It's also the reason why I want to put tools in there, because I want to just build a crate for future use rather than building one to size for our robot. I can fill in the extra space with tools.

popnbrown
07-04-2014, 17:46
We add eyelets to the sides around the bottom and midway up the crate to use as tiedown points. Then use wide straps wrapped around the robot bag mid to top points of the robot superstructure that gets tied to the mid-level eyelets. Same around the bottom.

I think I understand the bottom, I'm not exactly sure how you tie it down in the mid. Do you wrap it around the robot and basically tighten it enough so that the robot would be hitting the wrap either way it went?


We reinforce the walls of the lower foot or so of the crate on the two forklift ends to better sustain incidental forklift misses. I'd suggest putting the door, especially if it's hinged, on a side the forklift won't use. We've lost a couple of doors to near misses by forklift operators over the years.

How do you reinforce the lower foot? I'm planning on building a frame and mounting the 1/2" plywood to the frame. So there's a 2x2 at the bottom of all four sides, do you recommend throwing another 12" piece of 1/2" plywood at the bottom?

DonRotolo
07-04-2014, 20:40
Our robot is 43 lbs, so there's pretty much a very slim chance of going over the limit.Generally it is not the robot that puts one over the 400 pound limit. Plywood and 2x4s have weight, more than you might think.

For example, a 4 x 4 x 6' crate made of 3/4" plywood and reinforced in the corners with 2x4s, plus 2 4x4 forklift skids will come in over 400 lbs by itself, without a robot.

Our 'best' crate was 3/8" plywood, reinforced in all edges (except the floor) with a second layer of 3/8", 3" wide. Bolted eye bolts into and through the forklift skids (3 x 4 oak). Just over 200 lbs, and still in good enough condition to use (it is 5 or 6 years old now).

Mark McLeod
07-04-2014, 20:51
I think I understand the bottom, I'm not exactly sure how you tie it down in the mid. Do you wrap it around the robot and basically tighten it enough so that the robot would be hitting the wrap either way it went?

It depends on what shape the superstructure takes, but in general the strap is tight around some firm or substantial parts of the robot high up around the bag. Then the strap is tied to the eyelets either with left over strap or additional pieces of rope.
It forms a sort of spiderweb cushion for when the crate is tipped. Even tight, the ropes give a little spring to absorb shocks from drops, tilts, rough roadbeds.

How do you reinforce the lower foot? I'm planning on building a frame and mounting the 1/2" plywood to the frame. So there's a 2x2 at the bottom of all four sides, do you recommend throwing another 12" piece of 1/2" plywood at the bottom?

We add additional inside plywood for a foot or two up the front and back. The highest a forklift has speared our crate has been about a foot and a half above the floor. None of our robots have been damaged luckily, but they have gotten through the first layer of plywood.

801DOC
08-04-2014, 08:11
Here is a picture of our crate at Championships last year. It is now in its 5th year and still going strong.

Its basic features are that it splits in half with shelves that can be stowed to accommodate the robot. It has 4x4s on the bottom to assist with forklifting and we use a removable transportation adapter that can be attached to our cart to move the robot around. We used a thinner plywood on the sides for weight and have transported a robot, bumpers, banners and a robot cart in the same crate in the past.

In the pits, we use the bottom half for tote storage and the top hals as a work space. We install lighting on the top to add additional lighting in the pits but they can be easily removed and positioned on the robot if needed.

I have a .zip file with detailed pictures and can email it to you, and anyone else who desires. I think there are currently 5-10 teams who are using this design.

EVERYDAY!
DOC

"If you can't be perfect, at least be unforgettable." -DOC

popnbrown
08-04-2014, 14:37
I'm going to be ambitious and go for this split design. How do you hold the two half bottom pieces together? Unless the bottom piece comes out completely?