Made of aluminum, Made for aluminum: Would love design critique!

[Neale]

These Hiwin rails, for all practical purposes, have pretty well no alignment tolerance. They must be accurately aligned to, say, 0.01mm, in all dimensions. Can you control the width of the bed assembly, side extrusions, etc, gantry beam length, gantry spacer thickness, so that the total error in dimension is less than 0.01mm? The one big difference between home-built and commercial machines is that we don't have a giant machining centre that can give manufacturing accuracy. We have to build in adjustment at all key points. That's why the rails on top of the sides will let you build a good machine and your design will be a nightmare to set up. I understand your point about dust protection but keep asking yourself the question, "how can I adjust this on assembly?" For example, you could machine/shim the spacers to allow for gantry length errors, but how will you guarantee that the rails are parallel? Epoxy beds, bolts in oversize holes, etc, are all viable techniques in our workshops, however much they might be frowned on commercially!

You can spend as much time setting up as building, but that ability to tweak for accuracy is key. It has the potential to be a good machine if you can just sort out a few details like this.