Do the strut plates meaningfully increase stability/rigidity of the machine beyond the steel pipe construction, or are they primarily decorative and to keep dust away from the cables etc.?
Thickness
Relatedly, the LR4 documentation states
The two strut plates should be 6.35mm (¼“) or thinner of MDF or similarly rigid material, no ¼” ply, that is just too soft. Plastic or metal are fine, just harder for a new CNC user to cut.
How strict is this thickness limit? I do not see a potential for collisions with a few millimeters thicker bottom strut plates and for the strut plate one behind the core, there seems to be more space than 6,35mm to the core: Measuring with my calipers makes me believe 8mm should also work (8mm is the thinnest MDF I can get locally).
Cutting
With my ~1x1m build, I need 1219mm long strut plates. That is why I planned on cutting them diagonally on the work area, which would mathematically fit. However, I just read that cutting them diagonally may be more advanced, though to me this still seems easier than machining half, keying the material and turning it around for the other half like @Tokoloshe showed in another post. My work area diagonals differ by 2mm in length. Is this accurate enough to get fitting strut plates?
Ideally you get HDF in 5mm, it’s used for the back of wardrobes so it should be available and is absolutely fine.
That should hopefully work, just try with one. You are not “crossing” the diagonals after all. Flipping isn’t really hard either though, you saw the video.
IF 6.35mm or 5mm hardboard was truly impossible for me to source, and, I was limited to 8mm for reason(s), then, could maybe cut the 8mm thick struts and route out 1.65mm recess channels where brackets are, and potentially around the perimeter to clear the upper/lower pipes, so, extra strut thickness dissapears into the gantry void. This is the risky Macgyver path, if you have limited available resources, this is tougher and fraught with risk…
Recommend sunny happy path of buying 5mm to 6.35mm thick stock.
Thicc bottom strut might look and work fine.
edit: just checked my LR4, thicker than 6.35mm bottom strut will probably need a chamfered edge to avoid Core’s lower nuts colliding, and chamfer/notches near bolt heads for XZ plates might be needed too. Seems doable with 8mm.
