Let’s see… Blue pill joke… Fluffer joke… Concrete joke…
Check grub screws on pulleys, make sure belt tension is good. IIRC, it should be just past where it doesn’t really sag under its own weight. Not twangy tight. Make sure all bearings are making contact with rails. Check for backlash.
I really set you up for that one. Dammit. 
I’ll go through and check the machine again. Thanks!
Here is a great video example in case you haven’t seen it. The modifications, the advice on the first cu depth are all top notch and the files for the modified plates are in the description. Hope it helps out.