SOVOL SV08 fix "taco bed"

Сorrecting the curvature of the sv08 table or "taco bed".  

The idea of such modification belongs to @CheyzSnouck (view here). The base is a 3mm steel plate, cut on a laser and covered with powder paint. The design allows for table alignment at 9 points, achieving very good results at different temperatures. Silicone inserts (available on Aliexpress) are used as elastic elements, mostly 16-18mm. In order to maintain the factory level of the table, they must be cut to 14mm (a cutting template is included). In the metal plate, it is necessary to cut threads in 9 holes for fastening the table with heater. I used M3x20 screws (factory table fastening screws M4). Fastening the steel plate to the printer with original screws.

Additionally, there are holes for attaching various mods. As an example, a 5015 cooler mount for blowing out the space under the heater. It can be used as an element of the active chamber or for cooling after printing is complete for quickly separating the printed model.