Plans for building a Russian style cross, from Nikki Johnson.

There is no universal standard for the proportions of the post and bars of the cross. The three-barred cross varies some from tradition to tradition and manufacturer to manufacturer; for instance, some feature three bars that are all about equidistant one from another, but most have the third bar significantly lower. To some extent, just look at a number of crosses and play with the dimensions/angles until it looks right. However, here is a cross here that was made at a monastery, and maybe the dimensions will prove useful.

Attached is a rough drawing of the cross with dimensions, except the whole 12 inches would not fit on the page (I traced!).

The cross is 12" top to bottom and 1.25" wide.
The top edge of the top bar is located 1/2" from the top and the bar is is 3" x 1.25".
The second (main) bar is situated so that the center of the bar top to bottom is exactly 3" from the top of the cross and 9" from the bottom. It is 6" x 1.25".
The center of the bottom bar is approximately 4" from the bottom of the cross. The lower left edge of the bar where the two bars meet is 3.5" from the bottom, and the lower right edge is 3" from the bottom. It is 3" across measuring from straight edge to straight edge perpendicular to the main upright of the cross. It is cut so that the side edges are parallel to the main upright. The actual edge of the bar if you follow its edge along the slope is approximately 3.25" in length.