Here is my solution to jacking up my RV-12 when I have no help. I made two identical stands like this. (See photo below). The pad on top was not yet permanently tacked down when this photo was taken. The horizontal 4x4 is 25 inches from the ground and 26 inches wide. Here is the procedure: Place one stand under the belly between the steps. Jack up the stand with the small hydraulic jack until the base of the stand is high enough to slide the two loose 4x4’s under the stand bases. Release the jack pressure.
Since the main landing gear is still on the ground, the plane is stable roll-wise, so there will be no tendency for the plane to roll off to the side of the single jacking point as the stand is being raised off the ground. The top of the hydraulic jack fits into a 1 inch hole in the center of the vertical 4x4 to keep the jack from slipping out of place.
Now place the second stand into its proper jacking position under the bulkhead near the wing trailing edge. Jack it up until it is high enough to place the two loose 4x4’s under the base feet of the stand. Release the haudraulic jack pressure. The wheels will clear the ground by about 2 inches.
The front jack stand is supporting the plane stable enough in roll that there it will not roll to the side off of the single jacking point.
This seems to work well for me. I welcome any critiques on the design.
I could have used a 2x4 instead of the 4x4 on top of the stand to make it a little lighter.