Making mount plate and a moving test have been finished.
This additional frame gave me about 75mm of X axis movement and about 30mm of Y axis movement like a pic2 and pic3.
I thought, the best way for the smoothing movement is to add a roller to a movement point , but I applied Fluorine coating spray to a frame for now.
This lubricant gave me enough smoothness. So I can move the post frame by one hand. And the beam frame fall without rattling under its own weight of projector.
If frequently changing the size of the print area , this spray may be effective in the default plate.
(When it’s blown too much, it becomes white, so it’s unattractive looking.)
However, the defects was found in my blueprint.
It’s difficult to turn the bolt of the AC connector side, because the L-bracket of the mount plate is too short like pic4, and a height gap with a projector will be too small. I should make sure that a bolt can be put on the side.
And, it was forgot that there is a foot of a projector, so I had to add a 5mm spacers. When using it by 100μ, print area may stick out of a build plate.