UPDATE 04.07.2019 7:00 PM
I removed the screws and springs that hold the heated bed, the acrylic bed support and the PLA supports. The PLA supports in this thing were not warped as I thought. The acrylic bed was curving due to the pressure of the springs. I think the Tevo Tarantula springs are way too strong for the acrylic.
So instead of using the springs, I used small 3mm x 5mm screws and 12mm hex standoffs in place of the screws/springs. The heated bed is now at a fixed height from the acrylic bed support. I adjusted then Z end stop and placed a 1.5 Z offset in the slicer. So far so good, much better than before.
UPDATE 04.07.2019 3:00 PM
I tried printing PETG for a few days with bed temp at 80c. Because the screws get connected directly to the PLA supports underneath the acrylic bed, I believe the PLA supports melted a bit and got warped. I am now having to re-do my bed level when going back to print PLA.
If you are going to use this mod, I suggest printing the bed supports in PETG or ABS. I am going to see if I can get them mounted somewhere else underneath the acrylic plate so there is no heat transfer from the bed. If you don't use a heated bed, then there is no issue.
I designed these parts so that the print bed is supported along the Y axis using 8mm smooth rods and LM8UU bearings. The Overall.STL is there to show how the parts come together. With this setup, the wheels and the piece of acrylic that they attached to are not needed.
The guides are used to keep the print bed centered on the Y axis while you install the smooth rods and supports. They can be removed after the rails are installed. Please note that they have small nipples as guides so that they can be inserted correctly underneath the acrylic print bed. Use small screws to hold the guides in place. The holes can accommodate up to a 4mm thick screw. I just used #6 round head screws.
The corner pieces have slits for wire ties that can be used to hold the LM8UU bearings in place and are held in place using the print bed screws. I have included a design for knobs that the nuts for the screws can be inserted in. Please note that you will need to adjust your Z height after assembly.
The supports can be held in place onto your wood platform using small wood screws. Try to get the smooth rods as parallel as possible in order to avoid any binds in the LM8UU bearings. I had to shim one of the supports with a piece of paper to get a small bind out. My wooden printer platform may be slightly warped.