Update, dovetail angles...

Okay record...This is just an update, people continually ask me how to determine angle of dove... This seems to come up quite a bit. Very simple. Take the length you'd like for the dove, my example here will be five feet. (I'd like a five foot dovetail) So we're adding five feet of length to overall usable bed space, at 8 feet wide, that adds 40 square feet. I did it by the numbers. We know we have to get to the ground, I've already got five feet planned for dovetail and I'm going to fabricate flip over ramps to match bed height in travel position so that my usable bed space is all flat for hauling things loaded by forklift. (stand up ramps are much easier) I suggest making a mock up with wood, maybe 2X4's 10 feet long. The angle depends directly on your bed height, in some cases with a higher bed you will need a longer dovetail and ramps to get to the ground. If you're making flip over ramps and you'd like to add loading surface level with bed you'll need to keep some key points in mind.

The ramps cannot be the full dovetail length. (same length doesn't allow surfaces to mate level)
The front legs/feet on ramps must contact ground (only when weight applied) forward of ramps themselves. (if legs/feet are directly under the front of ramp, when the weight transfers from ramp to dove the ramps will lift up at the low end causing major damage to wheeled vehicles)
Ramps cannot contact ground when lowered to ground, the front legs/feet would stop ramp from getting into lowered position.

To determine the angle correct for dove, position your 2X4's at matching level of bed with opposing end on ground, Measure your angle. Mine worked out to be 15 degrees. All that matters is a balance between ramps and dove and you must get to the ground.
The perfect system isn't possible. You have compromises and are looking for the best compromise for your application... You can always use wood to compensate for needing to load irregular items. in fact, to load my forklift I will lay down 3/4 inch plywood on ramps and dove to make it smoother on small forklift wheels and distribute the weight better. To load my VW Passat (low to ground) I would need to raise the car with wood 3-4 inches and adjust ramps accordingly. So basically, my ramps are too steep to load cars. Trucks are a non-issue. Tractors, wheel loaders, rough terrain forklifts, manlifts and such would be perfect for loading. Lower ramps, drive on, chain and roll...

Been busy working people. Ramps completely installed with assist springs and primed. I'll come back to the install to share details about assist springs, solid hinge rod etc. I need to do bids for work. Also, I had all ramp diamond plate sheered to exact size for simplicity and will weld the sections on as time permits.
NOTE: Full spool of copper coated .045 welding wire ran out doing some final welding on ramp structures. (50 lb spool, all of it in trailer... I just loaded a spool of copper coated .035 (44 lbs)

and I'm enjoying it in relation to the .045, pleasant change...)