The mill is starting to come together. I have completed the x axis gantry, and am starting to get a sense of how much space this takes up.
When I was originally planning out the mill, I was going to hold the trucks on with bolts holding the edge of the truck. Then I thought that this wouldn't have enough holding power and decided to instead hold the trucks with bolts traveling through the truck and board, cris-crossing halfway through. To line up the holes, I clamped the truck to the board in the correct location. and drilled through the hole in the truck to align the holes in the board. This worked, however it was almost impossible to get the angle correct, and half of my bolts were to short. To correct this problem, I routed slots where the bolts would go in the hope that they would slide in the slot and give me a way to adjust the truck.
These slots proved very time consuming to make, and didn't provide the freedom I hoped for. I was able to make the trucks fit, however I wasn't able to adjust them the way I hope.
So I reverted to My original design which so far seems to be working better than I thought.
To get the correct length for the top and bottom pieces, I had to hold the sides in the correct location. This was done with the help of some bar clamps. I built the mill sideways because I had no way to hold the two side pieces in place vertically while I also set up the clamps. The top and bottom pieces were cut out of more MDF, with the holes for the nuts cut out on a scroll saw.
Here I have two holes cut while the third has a pilot hole drilled for the saw blade.
When you tighten down bolts in MDF, make sure that you have washers on both the nut and the bolt.
Otherwise this happens. ;-)
Also, when assembling the x axis, it helps if you bolt the top plate on first. this holds the sides in place while you slide it on the base.