TDC FOR HOP UP 26MM AIRSOFTPRO (AP-8995)

TDC stands for "Top Dead Center". Term used mainly in relation to internal combustion engines and expresses the position in which the piston is in the cylinder in its maximum (highest) position. In airsoft, this refers to a device capable of gently pressing the hop-up chamber arm (usually by means of an adjustment screw) from the top. To form its upper limit (CCT) without unwanted will. In addition, the control is more sensitive, smoother and usually to a greater extent than the conventional lever control.

Offered AirsoftPro TDC is a simple device suitable for a wide range of airsoft sniper rifles. Rotating the ring adjusts the pressure of the chamber arm and changes the path of the fired ball. The device offers the user greater precision and comfort than adjusting with a screw or a lever. There are two types, which differ in length, mounting screw position and lower arch for different main diameters. See table below.

TDC equipment is made on precision aluminum alloy CNC machines. It consists of a base and a control ring. It is positioned above the outer barrel. Just above the Hop-Up Chamber. The low profile does not interfere with large rifle scopes with a sun visor. TDC is not primarily supported by gun manufacturers and cannot simply be fixed and bolted on. During installation it is therefore necessary to partially disassemble the barrel, measure the position of the chamber arm and drill a hole in the outer barrel exactly from the top. The adjustment screw of the TDC device passes through this hole. By rotating it, its length changes and raises or lowers the camera arm. This changes the flight path of the ball.
In most cases, the TDC must be glued to the barrel with instant glue. The package includes an M3x10 screw, which can be used to screw the device to the chamber via the barrel. This screwing is logically better than gluing, however only some of the original chambers have a threaded hole. A typical example is the room for MB01 / 04/05/06/08/13 Well. Newer AirsoftPro cameras also have this thread on top and are TDC compatible.
An orienting level should not be overlooked, which not only serves for a more accurate installation of the device, but is also suitable for shooting. Tilting the weapon left or right will cause the bullet to bend and therefore less accurate. A cursory look at the level can correct this error.

Basic features:
Steel construction
Original design
Precision CNC machining
Rounded edges to avoid getting caught behind the gear
Sensitive adjustment (1 full turn = 0.5 mm stroke)
Control Ring Position Lock - 26 positions per turn. One position = 0.02mm stroke.
Built-in spirit level
Possibility of fixing to the chamber with screws (only some types of rooms)
Suitable for external drums with a diameter of 26 - 30 mm

The TDC adjustment screw must pass through the outer barrel on the chamber arm. Measure where this hook is in the barrel and drill a hole in the barrel casing vertically from above. Use a drill with a diameter of at least 3 mm, optimally 3.5-4 mm. A bigger hole is not a problem. If you glue the TDC to the outer barrel (in most cases), a hole is sufficient. If you are screwing the TDC (typically for Well MB01), we drill two holes - see table above - axial distance of the fixing and adjustment screw.