I am a one-track minded person. Often when my wife and I are watching television she will start talking and I don’t hear her at all. When she finally does get my attention, “Did you hear anything I said?” is her comment. Most of the time I did not. It is not that I am ignoring my better half. The fact is I can talk or I can watch television. I just can’t seem to do both at the same time.
One-track mindedness is not always bad though. Often it allows me to focus on an idea, see it and make it work in my head before I actually try to make whatever it might be. Most of the time the idea works out.
The latest issue of Popular Woodworking Magazine, June 2018, features one of these ideas that came to me while on a long boring stretch of I-40 in eastern North Carolina. The knockdown sawhorses I wrote about are made from yellow pine construction lumber, very strong, simple and have no wiggle when assembled. They can also be built with nails or mortise-and-tenon joinery.
The legs attach to the beam with dados and a wedge to hold it all tight. Assembly or disassembly requires just a couple of mallet taps. 
— Will Myers
I would make at least pair of these, however just doing a check on line there is not Southern Yellow Pine within 100 miles of my location in Southeastern Massachusetts. Is there another species you would recommend?
Anything that is cheap and readily available.
If lacking in either jack stands or sawhorses, a well built bed will also support your vehicle during routine maintenance:
https://www.facebook.com/177113804239/photos/a.10150105893679240.293011.177113804239/10152893025834240/?type=3&theater
How confident were you that horse would hold the truck when you first tried it?
I let the jack down and got the heck out of the way!! I was pretty sure they would hold, figured if there were a failure it would be the tenons on the short stretchers between the legs.
I too put all my mental energy and capacity into the single activity that engages my mind. It is not a popular trait with spouses. I also think three dimensionally and finish every detail of a project before I begin, whether woodworking or other material object, right down to the dimensions of each part required. The result is there are no plans on paper to share – which can be hard to explain sometimes when the finished piece is not constructed in an obvious way. I lose a lot of sleep because if I wake in the night the latest idea I have had will take over and the entire project runs its mental course. Good thing I am retired and have no set time I need to get up. And at least there is no one present to be offended by my apparent out-of-body states!
For several years it was my job to …clean critical computers of material the user’s had ‘no idea how it got on there’. It was my misfortune to be exposed to incredible amounts of bizarre fetishry( is that a word?).
Today, I can add one more to the bag: balancing vehicles on furniture. I’m afraid to look at the sub-reddit for it…
I’ve looked at these pictures, and I’ve read the article in PW, but I still don’t fully grasp how this thing is staying together. Could you post a few more pictures that show exactly how the wedges are locking everything together? Thanks!
It looks like it’s just friction. If you were to, for some reason, bolt the sawhorses to the floor and then put a jack under the top piece, I think you could probably lift it clean off.
Since this isn’t the direction force is normally applied to saw horses, I think you’re probably fine.
I think my bigger concern would be a shearing or racking force along the long axis of the sawhorses in a situation where the base can’t slip with the force. The bridle joint alone resists this force. Again I doubt this would become an issue in most typical sawhorse use-cases. Just the same, I’d have been primed to run when I let the jack down too!
I suppose you could always cut a small keyway in the uprights where the wedges hit for the friction fit. This would help support them when lifting as well.
Great Horses , Batman !!