Here's a design for Jack's pop-up chuck box. Jack's requirements were pretty simple, but I added these additional requirements:
- The chuck box shouldn't be permanently bolted into the tub -if a chuck box were a permanent installation, other uses of the trailer might be limited. So this design can be lifted in and out very quickly as needed.
- Other gear in the trailer shouldn't need to be unloaded in order to deploy the chuck box. Jack said for his use, unloading first was fine, but it seemed to me that for more general use by other people, it would be best if the chuck box could be deployed without unloading anything first.
- The mechanism hardware should be easily obtainable, inexpensive, reliable and should operate smoothly and easily. Off-the-shelf parts is the goal. This needs to be a DIY project accomplishable with no more tools that it would take to build a Dinoot kit (saw, drill, basic hand tools).
So with Jack's requirements plus the above in mind, I came up with the following.
The views above show the box from the back side so the mechanism can be seen, I posted a front view the other day.
It's really nothing more than a box (gray) with a drawer in it (light blue). The only thing unusual about it is that it opens vertically instead of horizontally.
The entire chuck box is self-contained. It can be lifted in and out of the trailer very easily. Perhaps a few latches might be used to hold it in place if it tended to move around when the trailer is in motion. Because it lifts right out, when it's out the trailer can be used for other hauling needs.
Because it is basically a drawer, drawer slides (yellow above) are used for the sliding mechanism.
Assisting with the lift is a pair of gas struts. These are inside the box, under the drawer. With the proper struts, the chuck box will be pretty much self-deploying - just like the hatch on a minivan, all you've got to do is start it in motion and the struts will lift it the rest of the way. The drawer slides will ensure smooth and accurate motion.
Here are some end and side views, they should be self-explanatory given the perspective views above.
The "cabinet door" is shown in green. It's in two parts - the bottom part fills the gap between the chuck box and the tub where the tub flares out. A single larger door could be used instead, hinged at the bottom.
The drawer slides will have to be a type that can be used vertically - some slides allow the drawer to be removed by lifting it off the slides, but these won't work in a vertical orientation. Slides with hold the drawer rails captive are called for. The struts need to be chosen based on the weight of the full chuck box and the eight it is to be raised to, bit I'd bet minivan hatch struts would be pretty close to the mark for both strength and length.
In addition to latches to possibly hold the box in place on the floor of the tub, the drawer will probably need latches to hold it in the stowed position. Don't want to hit a bump in the road and have the chuck box pop up
.
Construction should be pretty straightforward - probably 1/2" plywood for all of the parts would suffice.
Sawhorse-style legs could be constructed so the box could be removed from the trailer and set up on its own legs, perhaps over by a picnic table. Or without the legs, it could be set directly on a picnic table. Or, the box could be attached to a receiver rack and used for tailgating, where it might be impractical to bring the trailer.
I hope this meets Jack's needs.