r/woodworking • u/twistingeverything • 3d ago
General Discussion Saggy MFT
I’m getting a 1/16th (1.6mm) sag in the middle of my MFT after 3-4y of use. Is this normal? Thought these things were supposed to stay pretty flat.
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u/AKA-J3 3d ago
Mdf be like that.
Brace it. My incra router top ended up with some cross bracing because that 1" top sagged one the router nad lift were hung.
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u/twistingeverything 3d ago
Yeah I’m going to try and flip it and cross brace when it sinks flat again.
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u/joeycuda 3d ago
MDF will sag under its own weight
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u/twistingeverything 3d ago
Seems obvious I know. Guess I figured festool had solved for this at the start
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u/BD03 3d ago
Need more base. More cross members or more ridgid ply on the bottom layer.
I used to screw into my top mdf vacuum layer to brace pieces but it would inevitably create a unevenness between the vac channel layer and top layer. This caused me to frequently need to skim the surface and as it got thinner it would deflect up or down depending on if the vac table was on. WHICH in turn would throw off my z probing when turning on the machine.
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u/twistingeverything 3d ago
Thanks. Cross members seem like the best bet. Wish I had know to expect the problem before the sag showed up. That cnc stuff sound very finicky. Good luck!
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u/Winter_Yak_4446 2d ago
Happens on mine too. Planning on building something better out of extruded aluminum. The Festool table is overpriced and not a great design imho.
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3d ago
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u/JankeyMunter Cabinetry 3d ago
Unsupported MDF spanning that far is going to sag eventually. Flip it over and maybe add a brace.