air compressor assembly 10 when the engine is operating and to prevent the unit from sliding when placed on a relatively smooth surface a control panel 32 is provided on either the first side 22 or the second side 24 in the embodiment shown the control panel 32 is supported by an upper horizontal and a lower horizontal member of the first side 22 the control panel 32 is further described in reference to fig3 a rear support member 34 is provided to structurally join the first side 22 to the second side 24 the rear support member 34 also serves as a portion of a frame rotation stop point where the frame 12 contacts the ground surface as described in better detail in reference to fig5 in a preferred embodiment the rear support member 34 and the support plate 26 are each welded to the first side 22 and the second side 24 as shown in fig2 the frame 12 is configured such that the component group 14 is totally enclosed within an envelope of the frame 12 an assembly longitudinal axis a is shown bisecting the frame 12 the fluid pressure tank 16 includes a tank longitudinal axis b positioned approximately perpendicular to the assembly longitudinal axis a as best seen in fig3 the control panel 32 is supported at both an upper and lower extremity to the frame 12 in a preferred embodiment the control panel 32 is mechanically fastened e g welded at joints 33 to the frame 12 the control panel 32 is shown in fig3 in a generally vertical orientation however the control panel 32 can also be.