Sota Comet Grounding question

Hi,

I recently picked up a Sota Comet with a Jelco JA 250st tonearm for cheap because the arm needed rewiring. It was my first time rewiring, I used cardas wire and tags, and attached a ground wire inside the arm tube as well as one attached to the arm base. All the wiring connects to a terminal in the chassis, where the rca cables are soldered. The two ground wires connect to the grounding cable which runs to the lug on my preamp.

The question I have is regarding the ground lug that is at the bottom of the chassis. It looks to me like this lug connects to the motor. Where do I connect a ground wire from this to? I am getting an awful lot of static whenever I touch the platter which can be heard through the speakers, and occasionally when I touch the tonearm. There is no hum and everything sounds fine when a record is playing, but as far as I can tell the chassis is not grounded to anything which I’m hoping once this is done could solve the static issue. I tried running a ground wire from this chassis lug to the same lug on the preamp that the tonearm is grounded to which did not resolve the problem. 

Can anyone help me resolves this. I don’t get static from my Thorens or Rega tables, so I hope this is specific to the Sota turntable and can be easily fixed.