Reply by NiteWalker

I have 3 690’s and haven’t had this issue; all are made in mexico models.

The lever clamp was one of my first suggestions; my dewalt 618 plunge base was having an issue with the router motor shifting in use until I tightened the lever clamp nut.

The other thing it may be is the bit in the collet. Make sure you’re not bottoming it out; this can cause the router bit to shift height in use. The proper way to handle it is to insert the bit and pull it up about 1/8” so it doesn’t bottom out when tightening.

-- He who dies with the most tools... dies with the emptiest wallet.