Thanks Jage but actually I'm the least artistic person around.
Undervan Storage Box
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Using the measurements I took when I loaded down the van with half a ton of blocks and the dimensions from under the van I came up with a preliminary plan for the "box".
These will change.
Rough calculation of the inside area excluding a few important things like the thickness of the box metal.
Figure total box as if square.
28" wide x 20" high x 32" deep = 17,920 cu in
Calculate angled part
15.41 x 5.5 x 32 x .5 =~ 1,356
Calculate beam
2 x 3.5 x 32 = 224
Subtract
17,920 - 1,356 - 224 = 16,340 cu in
1 cubic foot = 1,728 cu in
16,340 / 1,728 =~ 9.5 cubic feet
Since the box will be made of metal I have to be sure of the measurements before it's constructed. I'll make a full sized mock-up from wood to check it's fit.
Here's a picture of the highly detailed plans I'll be working off of.
I dug into my bone pile of scrap lumber to make the mock-up. It doesn't look like much but It's outside dimensions are accurate to 1/4".
Beside checking how the box will fit under the van I'm also worried about ground clearance. Here's what I came up with to test the clearance.
Take four large binder clips. You can get these at an office supply store. I keep them around the house since they are perfect for re-closing potato chip/snack food bags.
Take off the handles and screw the binder clips to the four places on the wooden mock-up where I want to measure clearance.
Make up four plywood sticks. One for each of the binder clips. Mark each stick in one inch increments. I've marked each stick so that when the black line is even with the bottom of that binder clip, the number below the line shows how many inches the end of the stick is projecting below the lower edge of where the box will be.
The strings are in case the sticks are knocked free. Was too conservative with the amount of markings I put on. Should have added several inches. When I started testing ended up using a tape measure to supplement the numbers.
Mount the mock-up under the van. I could get it under the back of the van by using the little drop-off at the edge of my driveway and since it was really just a skeleton of box I could maneuver it around more. This won't work with the real thing.
Right off the bat I found I'd made a mistake in measuring the distance from the back of the van to the under floor beam. Some quick work with a saw will fix that.
Put it back under the van again. I'm using several claps to hold the mock-up into place.
if I make the box this size it will interfere with the charcoal canister. The stick on the right represents the most forward edge of the box.
Also the front passenger side corner is uncomfortably close to the exhaust pipe.
Here's the corner I just cut to clear the undervan beam. I took off an inch but I could get by with 1/2".
Enough of that. Let's do some road testing. Here's the basic plan. Find something that I might have a ground clearance issue with.
Climb under the van and set all the sticks so they project from under the mock-up the same amount.
Drive over the obstacle. Check the sticks. If they haven't moved or been knocked free, lower them each one inch and drive over the obstacle again.
Keep doing this until a stick finally makes contact.
Then I'll know my max ground clearance for that obstacle. Move on to some place different and reset the sticks. This time I'll try the most gouged up street intersection in town.
Perfect place for a test like this since the angle of the two streets is such that lots of vehicles bottom out. I drove this several time going both directions and different speeds.
Always changing the stick position until I got a result.
I'm doing these tests at first light on a Sunday so there is no one on the road but me. Otherwise it might have looked suspicious with me driving around the same neighborhood in a white van over and over again.
Since there was no one out (police) I started driving over curbs and other things just to see what kind of results I'd get.
When I as finally finished I found that there was never less then 5 inches of clearance at the point where the 20 degree angle starts and 7 inches at the rear most point on the box. Now these numbers are with the van not being loaded so if you take in consideration the cement block test that would reduce each of these numbers by one inch.
I'll still have to make some adjustments to the box size before I'm happy but ground clearance doesn't appear to be an issue with this design. Keep in mind that I don't plan to go off-road with the van. Off-pavement yes but not off-road.
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