make sure the axle isn’t cocked (high on one side and low on the other-cassette bolts). axle bent slightly? No burrs? Middle cassette run loose I hope? Don’t over tighten the top cassette bolt.
If you run a floating sprocketthe wiggle is normal. If not make sure it is aligned with a straight edge with the front motor gear.
Hey freeze how much does it cost to use the “get bent racing” table?
good luck
rich