Thanks for the kind comments :)

As I hadn't really got the means to machine the mounting faces of the gantry feet properly flat, I intended to use epoxy as a shimming material and to adjust the gantry alignment before the epoxy set.

I fitted studs to the holes in the base and to try and stop the epoxy squeezing up the bolt holes in the gantry, I put an O ring around each stud.




The studs themselves and metal faces were also given a coating of furniture wax to act as a release agent (in case it needs to come apart). After a dry run with bits of packing, etc. to make sure it was possible to get it all set square, I masked off the area around the joints and gave the mounting faces a liberal buttering of epoxy:




There followed a frantic and stressfull couple of hours trying to get the gantry level to the table (side to side), and square to the Y rail travel and standing vertical (nod), all at the same time. I'd bought myself a 6" square to act as a reference, but I only had the one, so had to check each direction separately (with the square lightly clamped in place), make an adjustment, then go back and find out if it had affected any of the others (usually it had!). Do you ever wish you hadn't started something at 10:00 at night?

I'd put jacking screws in the flanges on the gantry feet to help with this process, and while they worked fine for levelling the gantry and correcting for nod, I'd completely overlooked the need to adjust the angle of the gantry to square the X and Y axes. The O rings I'd fitted on the studs were quite effective in keeping the studs centred in their holes - not where I wanted them to be! After a lot of sweat, frustration (and almost tears), I got the gantry and table reasonably squared (I ended up hammering a screwdriver down one of the stud holes to stop the blimmin' thing creeping back on me ).


I managed to get the 'nod' to ~0.01mm over ~100mm




And the axes square to a little bit better than that




And got the gantry levelled from side to side to within ~0.03mm over ~200mm as far as I could tell with the slightly warped table.





There was a healthy amount of squeeze-out from the joints that also had to be cleaned up before I could get to bed.




After a couple of days for the epoxy to go off, I fully tightened the nuts on the mounting studs and re-checked the perpendiculatity, etc.




With it together, I hastily cobbled together the basics to drive the steppers with GRBL on an Arduino. It's not pretty:




It would draw pictures though :)




After driving various bits off the end of their linear rails a few times (and having to play hunt the ball bearings) I decided to fit the homing/limit switches (I found some nice little normally closed inductive proximity switches that are only 6mm dia.)

The X axis homing/limit switch fits into the X/Z adapter and is triggered by 'flags' on the top of the gantry: (I was going to fit limit flags at each end of the travel, but ended up with just one that is used for homing.)




The Z axis switch fits into the hole on the other side of the X/Z adapter plate, but facing in the opposite direction to the X one. It's triggered by 'flags' on the side of the Z axis. (The Y axis one is under the table).


I also fitted a cable chain, etc. and did the final wiring on the machine side of things. There's a couple of tubes there intended for an oil mist style lubricator and a solenoid for the same on the side of the machine.



I'd originally (rather reluctantly) decided to make the working table out of MDF, but then a decent sized offcut of 15mm tooling plate popped up on ebay. After cutting it to size, I clamped it to the Y carriage and used the machine itself to drill holes through the work table and the carriage below it. The first time it cut anything in anger, and my first CAM program (the mouth was very dry before I pressed the button...)





Unfortunately, in the process, one of the clamps decapitated the Y axis homing switch!