CNC MFT... is there a top and bottom face?

[MattChow]

I purchased a CNC cut replacement MFT top and spent a good few hours trying to get a square cut.

Doing 5 cuts around a board that was approx 500 x 500mm left me with approx 2mm of error on my final slither cut.

I checked the blade was true to the guide, that the rails werent bent etc but everything checked out ok.

After some time I then fipped the top over, the dogs (that came with the top) seemed slightly more snug and i got some good results.

Anyone know of this is normal for a CNC cut MFT? Is there effectively a "right way up"?

 

[Setch]

If you're getting or if square results, I'd try a fresh blade. Even a slightly dull blade seems to deflect away from the rail and compromise squareness.

 

[MattChow]

Worth a go i guess but doesnt explain why i get a better accuracy with the top up one way compared to the other?

Im wondering if the holes have a slight taper