Fixed Gantry small precision begineer project advice

[yasu]

Hello everyone,

Most of the projects i have seen here are mobile gantry so i guess my machine will be uncommon due to the small size. I am completly a begineer so feel free to shout me if you notice something shamefully wrong, i appreciate any advice.


I wanted to build a machine for 3D work, mostly propellers and parts of small RC planes ,and maybe jewlery and engraving. So these are the constrains and requirements :

-Small cutting forces due low deep steps(400-800w spindle) ,
-High accuracy and no backlash
-Not any speed/aceleration requirement, not a problem if a job takes 8h or 20h .
-Weight that allow to move it with the table (no frame, clamped on table) withouth a lift machine or disassembly the stages.
-Arround 170x120x52 mm workspace
-Easy alignement or low amount of tooling required


This is the preliminary design (although the aluminum of the plates of the Z column is not ideal due to the fatigue problems of bending in a few years, my concern is more about the rigidity of the design ):



It has profiled rails Hiwin HGH15 , and ballscrews 1402 or 1605 L160/250/300mm, Nema23 , both ends fixed although i didn´t draw because i still have to choose the exact end fixing, nuts, motor support, pocket dimensions etc... But the thickness of the plates of the column is 30mm and the basement of x stage 25mm, total weight arround 25-30 kg withouth motors/spindle.


I have some doubts about the alignement of the stages:

-For the X and Y squareness i found a video that does the same steps i am going to follow https://www.youtube.com/watch?v=UETVKpmWTL0

My idea using a combination of machinist square and gauge block to square the X rail to de Y plate, instead of the ground angle plate he is using because it doesn´t seem to me enough accurate those that i have found.

-For the Y and Z squareness i have thought this, and i wonder i the machinist square is enough straight to alignement of the rail as a straight edge