Here we go again . . . MK4

[routercnc]

OK here are the detailed measurements showing how far off 96mm width the parts were (!). I think they slipped / tipped in the fixture, which I couldn't tell as I couldn't see the ref surface they were sitting on during the machining.



They are out along the length, and across the width. Annoying but there we go.

Current plan is to machine them square again (but obviously they will be undersize for width). Here is a sketch of what I'm thinking of attempting on the lathe:


I've bought some 5mm thick aluminium strips which I will superglue and bolt to one of the edges using countersunk cap screws, setting them well underflush. Then I'll machine the edge back to get the part 96mm wide, using the lathe again, and then remove all of the screws (except the ones at the far ends which will hold the strip on, along with the glue). I can then attach the rail. Should look like this if all goes well:


If it doesn't work then the strip can come off and I'll try something else. Thought about epoxy levelling all 4 surfaces, which I think can be done if I start on a level surface and do it in the right order so they all end up parallel to each other.

Another option is to do both sides but use steel strips instead. Then get them ground in pairs on a surface grinder so they are parallel and flat to each other.

I knew this bit was going to be challenging, but it must be right otherwise it will bind or not track straight up and down.