Swiss cheese plywood bed frame

[jacks18614]

Ford MoCo per my owners manual says the Transit Connect will lose 1 mpg for every 400 pounds of cargo weight.

My goal is to be as close to 300 pounds of dry weight for my upcoming conversion and another 200 pounds wet weight which will include a full 15 gallon tank of fuel and up to 8 gallons of water (6 gallon Rubbermaid blue jug w/ two handles) and a 2 gallon black can sprayer. When you add the drivers weight this comes to 50% of the TCs cargo capacity of 1600 pounds.

Now my question is using a hole saw of the diameter of your choice what pattern would you use to lighten up a 3/4" plywood bed frame (30"x72") using 2"x2" base sturdy enough to handle a 300 pound animal?

 

[Minivanmotoman]

Fifth Element sells a kit like that.
Check it out. Look like 2-3" holes?

https://fifthelementcamping.com/

 

[Weight]

I built a perimeter frame using 1x3 pine and my trusty Kreg Tool. Then I used peg board to cover into a platform.

 

[eVansdale]

3/4 inch plywood sounds like a lot. Could you go thinner? 3/8 inch plywood is the same weight as 3/4 with 50% holes. That would take quite a while to drill.

35 lbs of 3/8 in ply vs 70 lbs of 3/4 in ply. Of 4x8 ft sheet.

 

[John61CT]

Plastic grids for greenhouse beds and lightweight aluminum framing every 24".

 

[maki2]

Plastic grids for greenhouse beds and lightweight aluminum framing every 24".

Lightweight aluminum framing every 24" and 1/4" plywood also works just fine. Most people build things incredibly heavy never realizing that it is not necessary to do so.  Aluminum angle is faster and easier to build with than wood. Cost a little more but you get that back quickly in fuel savings. Think airplanes...they need to be lightweight and very strong and durable.

 

[BinDerSmokDat]

My bed platform is for an RV queen 60" x 75" width-ways in a Ford E-150.
There are storage boxes around the wheel wells so the widest span is 44".
It has to hold two adults; I'm 6'6" and 250+lbs, my GF is considerably smaller.
I made composite bed supports spanning the boxes using 1.5" tall hardwood and plywood.
Running the plywood lengthways along the wood, gorilla glue and screwing every 10" helps keep the hardwood from deflecting downward under load.
The hardwood keeps the ply from flexing laterally.
I beefed up the end slat where i will be sitting on edge of bed getting in/out and putting on my slippers with a beam that is ply, hardwood, ply hardwood, ply for extra support.

The ply used for the bed supports and the top was 1/2" BC fir.
I did not drill lightening holes, as I want the areas over the boxes to be air, sound and water vapor-tight.
I tried a piece of 3/8" ply across the spans I used and it probably would have been fine.
I tried 1/4' and there was a slight amount of deflection which would have required more supports closer together.
In the end I had a piece of 1/2" hanging around and wanted to err on the side of caution so used that.

The system holds up well with the weight and when I climb into bed there isn't a squeak or creak.

I guess I could go back and drill lightening holes over the piece that spans between the storage boxes, but at 40lbs a sheet, the potion of the sheet that makes up the bed is about 18lbs total. How much lighter can I make it by drilling holes? Remember that lightening holes work best in vertical pieces that are under compression (think I-Beams with open holes/webbing or airplane wing supports) not in sheets that span horizontally and are subject to deflection.

 

[B and C]

You may want to drill holes in the bed platform to help prevent condensation. Pick your mattress up in the morning and feel underneath. Mold is hard to get rid of.

 

[John61CT]

That was the entire point of my reco

> Plastic grids for greenhouse beds and lightweight aluminum framing every 24"

plywood collects condensation, thin stuff breaks down over time

so gets "wavy" with heavy loads, thick stuff is too heavy.