excellent idea...
but how to do with the top ?...

I will use small steel plates and screws to fix them together. Will do it tomorrow and then post the pictures.   

I don't planning to use the 3/8" tube at the top for hanging the converter on it. I think this tube is not necessary for the function.
There are many other ways to mount the converter, either by hanging it on the top, or placing it on a rod connected to the base plane.

Skywatcher

Excellent idea! Well done!!

just a question how did you come up with the angels? what are your side lenght and your hight?

The angles i mentioned in my description are fitting quite well. The exact lenghts of the pieces is more important for the result as the angles.
There are some small gaps at the top of the pyramid, but i think that's not very important (look at the pictures in the following posts).

Mount two of the side tubes to the pyramid base so that they can touch themselves at the top.

Make the joining element out of a thin steel plate of 30 x 20 mm, bend it slightly in the mid, and cut the edges as shown on the picture.
Move the tubes so that they are touching themselves at the top, put the joining element on the inside of the two tubes. and mark the holes through the holes in the tubes using a permanent marker. Then drill the holes (i would recommend 4 mm, depends on the screws you want to use).

After drilling the holes, the joining element should look like this:

...and from the inside:

Hi skywatcher
what is the finished hight of your frame from the base to the toP? I tell you why My side's have a lenght of exactly 1000mm from the base of the pyramide to the top center and I only got the base angel at 46 degree on the side pieces.
greetings
walt

Hi skywatcher
very nice manual for building welding free pyramid thanks a lot. Only pity that I somehow overlooked this thread during my build. I could do at least the base better. Bellow are some pics from my frame it is not as elegant as yours but for me it's sufficient. Frame is not that relevant as long as it has right dimensions right?. Mine: height 70,5cm Width:96cm Edge:96,5cm. When I place rigips dimensions should be 1m for edges and base width. After finishing it I would suggest for other people to better weld it to get faster frame for experiments. Measuring, drilling takes its time. You may make mistakes and then it is difficult to correct. When welding you can still use hammer to correct it

MT

Hi, I have building  and experimenting with pyramids and their energy for over 30 years.  Yours is origional, well made, portable and of course very strong.  But the angle for pyramid energy is 52 not 54 degrees.  Was the previous post a typo and you ment to say 52?   Have you seen the geometry that proves its beauty?  I will attach a eligant gif file to so why it is 52 degrees.  no big deal, minor change.  Again - very well crafted project!
yon