Originally Posted by
catahoula
jackjr- gantry tube is 200x150x12.7wall, with 38mm W x 19mm H flat bar welded on for the linear rail mounting. It's 860mm long. Last night I was looking at the x axis rail spacing on the DMG Mori gantry machines and having a panic that I did not get enough vertical spacing on the gantry X axis rails. I'm wishing I just fabricated the gantry from welded plates- the 12.7mm wall thickness means the the tube corner radius is about 32mm, more than I expected from DXF's of standard AISC tube sizes. I don't know why I got so hung up on using a stock steel tube, could've easily used a 10"/250mm wide plate for the front face and that would have made a lot of design elements a lot cleaner and easier. But at this point I don't see a good way to boost the rail spacing without a lot of messy welding so I will probably just leave it as is, about 175mm rail spacing outside-to-outside. It's not terrible, and hopefully the extra heavy load carriages with preload will compensate to some extent.
Edit: gantry tube is 200Hx150W (8"x6" here in USA) not 200x200