This is from the WEN manual
https://cdn.shopify.com/Excessive vibration.
1. Machine speed set at a harmonic
frequency of the saw.
1. Adjust speed up or down to see if
issue is resolved.
2. Machine not secured to work surface. 2. Secure machine to work surface.
3. Incorrect blade tension. 3. Adjust blade tension (see p. 13).
4. Hold-down foot not being used. 4. Adjust hold-down foot to slightly
clear workpiece surface when cutting.
5. Loose fastener. 5. Check machine for loose fasteners.
6. Defective bearing. 6. Contact customer service at 1-800-232-1195
Hope this helps