Ridgid - EB4424 Oscillating Edge Belt / Spindle Sander (Rating: 2)

I purchased this ridgid sander 2 days ago after reading a lot of great reviews. The assembly went together very quickly and easily and the fit and finish of the sander appeared to be on par with the price. It wasn't until I installed the belt assembly onto the spindle that I first noticed something wasn't right. When installing the "spindle knob" (item 1 in the attached parts list diagram), I noticed that the threads were not even close to concentric to the shank of the knob. In addition to not being concentric they were also out of parallel with the shank of the knob. I unscrewed the knob, removed the belt assembly, and then installed the knob by itself to get a better idea of how poorly the brass portion of the knob was machined. As the knob was being screwed onto the spindle I could clearly see that it was the culprit. The knob was, in effect, acting like a lobe on a cam shaft. So, I went ahead and re-installed the belt assembly, tightened the spindle knob ("not too tight" per the manual) and turned the machine on. If it weren't for the rubber feet on the bottom of the sander the entire sander would have eventually walked off the bench. I have worked with power tools and machinery my whole life and know when a machine isn't operating correctly. This sander hand an EXCESSIVE amount of vibration and did not operate as it should. The cam action of the eccentricity of the knob was causing the entire belt assembly to wobble. This wobble, of course, was much more pronounced at the end opposite the spindle. Just to be sure that it was the spindle knob that was the problem and not the spindle I removed the spindle knob and turned on the machine without the spindle knob. ALL of the vibration was gone. It was definitely the spindle knob. Just to see if the machine would still be usable with this much vibration I installed the spindle knob and sanded a few pieces of scrap. The work piece would hop on the sander. It just was not useable at all. I decided to give Ridgid a call and see what they would say. The tech that I talked to suggested that it might be a bent spindle or something in the motor causing the vibrations. He suggested that I exchange the sander for a new one and so I went back to HD and picked up another one…
So, yesterday I picked up another one. I pulled the sander out of the box that evening installed the rubber feet, turned the sander over, loosened the table adjustment knob and raised the table. The table could not be raised level to the top. It felt as though the table adjustment set screws (item 38) were way out of adjustment and preventing the table from rising any further but this was not the case. The table wasn't even contacting either of the set screws. I then noticed where the problem was. I noticed that the problem was caused by a defect in the casting on the front edge of the rear table (item 11). It appears that someone forgot to run this rear table through the deburr process at the factory. I then proceeded to install the belt assembly just to see if this machine had the same issue as the previous machine. I quickly noticed that the spindle knob had been redesigned. The zinc plated washer on this new knob had a captive floating washer whereas the washer on the knob of the previous unit was pressed fitted onto the knob and would not move. This was interesting. Something tells me that they tried to correct the poor machining process by simply making the washer float so that it could seat properly to the top of the bearing on the belt assembly. Unfortunately they hadn't corrected the root issue of the knob. The threads of the knob were still improperly machined and were having the same effect on the machine as the previous knob was. Then I began to notice that this machine had too many nicks and scrapes to be a new machine. Yep, it was previously returned to HD and they did a great job of re-taping the box to hide the fact. Upon closer inspection, the 2nd layer of tape was placed perfectly over the first layer…absolutely ridiculous that HD would pull a stunt like this. This unit will definitely be returned.
I'm not even sure that I want to continue pursuing this sander. I read a recent comment by a user stating the following: "It seems everyone is praising the Ridgid sander#EB4424 but apparently there has been some shortcuts taken in the production of this sander lately,have heard complaints about excessive vibrations,or platten not being flat,overall flimsy assembly." I completely agree.
This is a friendly warning to all who have purchased recently manufactured sanders or are looking to buy. If you are having this issue I hope this can shed a little light on what's going on.

Update 04/21/2015-- "The 3rd Sander"
Yesterday I decided to give this sander one last chance. I drove to a different HD with hopes of obtaining a unit from a different manufacturing lot. I wasn't going to get all the way home just to find out the unit was defective so I just opened the box right in the back of the car in the parking lot and installed the spindle knob on the spindle. There was not a bit of cam action in the knob and I was beginning to think I had a winner. Once I got home I assembled the unit and turned it on…the difference was night and day. The vibration was gone. The front table also lifted parallel to the rear table as it should. Just a side note, the spindle knob is the older style with the zinc washer pressed onto the knob. What style spindle knob do you have? Captive floating washer or pressed on washer?

Update 07/01/2015
Regardless of which knob you receive, ensure that the threads are concentric to the shank of the knob. The pictures below illustrate the difference between the pressed-on washer knob and the floating/captive washer knob.

Pressed-on Washer
Chair Rectangle Tints and shades Font Armrest

Captive/Floating Washer
Tints and shades Font Rectangle Chair Titanium

Drawing of what I mean by threads not being concentric to the shank of the knob
Automotive lighting Art Font Automotive design Parallel