welding steel base or just getting aluminium extrusion

[Clive S]

Been thinking about how i am going to square the gantry up and thought of an idea using the method used below (watch from 2:20)

The way I see it is that all he is doing is aligning the rail to the same as the ali profile so if the ali is bent so is his rail

[EddyCurrent]

It sounds like you need to invest in some tools such as a straight edge, engineers square.
I attached one of the long X rails using a straight edge to get it straight, then it was easy to space the second rail from it. Once you have the bearings fitted and a gantry cross beam attached you can feel if the bearings are tight at any point in the travel and make adjustments to the second rail.
Here's how I squared the rest up; http://www.mycncuk.com/threads/6565-...5217#post55217

[reefy86]

It sounds like you need to invest in some tools such as a straight edge, engineers square.
I attached one of the long X rails using a straight edge to get it straight, then it was easy to space the second rail from it. Once you have the bearings fitted and a gantry cross beam attached you can feel if the bearings are tight at any point in the travel and make adjustments to the second rail.
Here's how I squared the rest up; http://www.mycncuk.com/threads/6565-...5217#post55217

read through your thread mate and i have a better picture in mind now so thank you, after reading about your problems with the bk12 bearings is this something i am going to run into when buying from zappautomation? mine will be the bk15 and bk17 not the bk12.