Project: Plywood Forklift Part 1

What problem are you trying to solve?

The doors on the loading dock for the workshop were built in 1932 and are not the right size for modern trucks and forklifts. The dock is about the right height for FedEx and UPS box trucks but is ten inches short for semi trailers.

When delivering a bunk of OSB, Lowe’s parks the semi on the street and has an all-terrain forklift to haul the material to the dock so height isn’t an issue. The forklift does force the orientation of the bunk so the length of the wood is parallel to the width of the sliding dock door. The dock door is only seven feet wide and six feet tall. We have a pallet jack but not a forklift, but a forklift won’t fit at the door height. The pallet jack only works on the long side of the pallet so when loaded with 96 inch plywood, it won’t fit in the door width.

Our first thought is to grab a sledge hammer and knock enough bricks out of the wall where plywood could fit through like a “silhouette of passage”, cartoon physics style. But, then we’d have to alter the door to cover the awkward hole we’d made.

The next idea is to build a better pallet to put the sheet goods on that can be used on the short side of the pallet. Looking around the shop, we found two sizes of pallet, one is about 5 foot long and the other is 7 foot, neither actually long enough. Loading a single sheet of plywood on the 7ft pallet, we experimented driving it around with the pallet jack. It quickly becomes obvious that unless we find a super long pallet jack or add a short one, this is not the answer. Storing heavy sheet goods flat on an uneven surface on a pallet is not a good idea either as some of the wood is getting slightly warped which impacts assembly.

The next idea is designing a mobile platform that we can roll out on the dock to load with material. Then roll it back in to where ever we want to store it, maybe near the robot if that material is being used in the active project. The key elements of the design is to make it flat to reduce warping and strong to store 3/4” plywood (42 x ~66 = 2772lbs/bunk).

The design technique that will most likely address both goals is called a “torsion box” (see good overview on Core77). Can we make one with OSB versus multi-ply sheet goods?

We start with a sketch in Paper by FiftyThree or on index cards.

General Idea

Construction Detail

Next

With the general idea put together, next we move into Aspire to design the actual parts in vectors. (We also use Adobe Illustrator and SketchUp.)