Hi IGN,

My first advice is to ensure you've read the gantry design threads:

http://www.mycncuk.com/threads/2023-...ign-principles

http://www.mycncuk.com/threads/9082-...d-Read-This%21

I highly recommend using extruded aluminium profile where possible; because its heavy duty profile it can be just as stiff as steel, and you shouldn't need to use Epoxy to level it, which makes the Y axis a LOT easier. See my build thread to see what I've done with the Y axis; its a very common design on here, and the aluminium profile only cost £50, which is about what I'd need to spend on epoxy to level it if done in steel. It also meant that the rail bolted on in 10minutes after getting it - on my X axis I used steel and epoxy levelling - that took WEEKS of work. Grinding, Welding, Drilling, Painting, Epoxying... I wish I'd used Aluminium on X too. On your current design, I'd say the Y axis looks quite weak - you don't really want open area between the rails. Theres also a gantry stiffness calculator somewhere on the forum where you can put numbers to your design.

Your gantry sides should ideally be wide enough to have the router bit fall between the two bearings. It does reduce X axis travel however. Your rail also doesn't go to the back of the bed - how come? If I were to have that shorter rail, I'd put the gap at the front so I don't lose travel distance over the bed.

Get a quote from Fred for Profile rail - it might be cheaper than you're expecting, and is a significant upgrade over SBR.