Tune your Festool MFT rail with Slop-Stop

Description

A cause of frustration for many Festool MFT owners is the small amount of "slop" where the rail fits over the locating tab. While this play can be minimized by adjusting the tab so that there is side-pressure on the rail, the steel tab eventually wears into the soft aluminum and the problem only gets worse.
The "Slop-Stop" is a insert that solves this problem and eliminates the metal-to-metal contact. To use simply slide the insert in the MFT rail, centering it where the rail meets the tab (often the wear marks will be an obvious indicator). Then lower the rail, slide the "slop-stop" in either direction until the desired fit is acheived, then lightly tighten the set-screws with the supplied wrench. Finally check your rail alignment.
The "Slop-Stop" is machined from delrin and will provide excellent wear characteristics, but by reversing/rotating the insert, there are effectively four wear-surfaces, enough to last the normal user for years.
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Update:  It has come to my attention that some  of the newer Festool rails may be manufactured to slightly different tolerances.  I do check all slop-stops against my rails for fit but if you happen to have a "smaller" rail and the slop-stop does not easily slide into place,  please do not "force" it into position.  Usually, easing the sharp outside edges of the slop-stop with a file or medium grit sandpaper will alleviate the problem (procedure shown in last pictures).   If this doesn't solve the problem, or if you simply don't want to modify it, I will be more than happy to accept a return and send a refund.  Thank you!