Qidi Max4 (X-Max4) drag chain frame rail guide

Just a ramp to stop the drag chain carrying the print head whip from smacking into the upper frame rail, making irritating noises and in some cases skipped steps.  The part as-installed in my machine provides a rolling paper's-thickness between the bottom of the ramp and the print head, so there isn't any rubbing on my machine.  The example print was made using a tightly-calibrated nylon filament which is dimensionally-accurate, but nylon gonna be nylon at times, so YMMV with other materials and printers.  Nothing fancy - form over function here - so it isn't the prettiest.  Ripples in the pic can be ignored, as that's due to me testing out some different support methods for my own prototype-turned-final print (it works, so that's the end).

Two models provided: One for using somewhat-longer M3 countersunk screws to keep the profile as low as possible (original), and one set up to use standard M3 cap screws (modification).  The difference is only 1mm of total height so it's not huge, but it's the less-tested version that might have some quirks (the holes are simply re-profiled and the top of the ramp is raised by 1mm).

One quick note: those screw holes are wonky from the manufacturer.  The screws they use are out of spec (smaller diameter) than your regular M3, so you may need to chase the threads of your machine using some extra pressure and a sacrificial M3 screw.  They are also not exactly straight - neither longitudinally, nor vertically.  They don't 100% line up between the top case and the metal frame, and they aren't exactly perpendicular.  The hole spacing is also kinda 'special', as-measured on my machine at 135mm between the back and middle holes, then 168mm from middle to front.  You may need to adjust the holes in your printed part a bit with a tool to get them fully in-alignment with wherever your screws need to go.

I ended up using 16mm countersunk screws, but your requirements may be different, especially if you use the standard M3 cap screw option.  Keep an eye on how much of the screws stick out below the frame and make sure the gantry carriage has clearance to move freely.  The top of the screws should end up below-flush with the top surface on both versions.

If any major revisions need to be made, let me know and I'll try to take care of it.  Otherwise, this one is final and won't be updated.