This TF2 paper craft is a SD style paper model, it is really a simple papercraft. This paper model is designed by Heyro0. The Sentry gun (sometimes known as a "Turret", "Sentry" or abbreviated to "SG") is a building that can be constructed by an Engineerand functions as an automated weapons platform that fires upon any enemy who enters its line of sight. The Sentry Gun will always target and fire on the closest enemy player or building, provided they are within firing range and in line of sight of the Sentry.
The Sentry gun costs 130 Metal to build, 200 Metal to upgrade to level two, and an additional 200 to upgrade to the third and final level. With each upgrade level the Sentry gun becomes more powerful, gaining machine guns, rockets and the ability to take more damage. The firing range remains constant regardless of level.
The Sentry gun's ammo may be replenished with your own metal by hitting it with your Wrench. Each bullet reloaded costs 1 metal and each rocket salvo costs 2 metal.
When placing a Sentry gun, the limit of its range is represented by a 3D sphere of your team color. A Sentry that is being constructed will have its health increase gradually until it reaches its maximum health upon completion. The Sentry rotates 90 degrees to patrol the area, but is capable of rotating 360 degrees to lock on to a target. This takes a brief moment however, which may allow faster foes to slip past its range. The Sentry can also be manually rotated to face a different direction before you build it: When the blueprint is shown, using the alternate fire button will rotate the blueprints clockwise by 90 degrees.
Sentry guns will not fire upon enemy Spies that are cloaked or disguised. Sentry guns are unable to fire if an enemy Spy attaches an Electro sapper to it, if they are being upgraded/built, or if they're under the effects of the Cow Mangler's Alternate Fire. A destroyed Sentry gun leaves 60 Metal worth of pieces, which can also be picked up by other classes as Ammo.
Unlike most other weapons, the sentry gun's weapons do not get affected with damage falloff from range nor can it gain criticals. It is possible however, to make the Sentry gun deal Mini crit attacks and damage if its target is coated in Jarate or if the Engineer who built the sentry is close to a Soldier with an active Buff banner, boosting the damage of each bullet to 22.
All level sentry's can be picked up when fully deployed only. When the engineer carries his sentry or other building, he walks with the speed of a heavy and can not use any weapons. When he gets killed, his carried building gets instantly destroyed, which gives a kill icon of a engineer box with a explosion. A redeployed sentry automatically builds back to its previous level and builds 2 times faster then normal or more when hit by a Engineer's melee weapon. A redeployed sentry has no health at the start of the build, just like a normal sentry. Once it has been deployed and before it reaches the end of its Level 1 animation, the owner can use the Wrangler to put a shield around the sentry as it goes through its Level 2 and 3 animations. At the end of its build animation to the Level it originally was, it will automatically start firing at any nearby opponents or be Wrangled. Sapped buildings can not be redeployed.
You can download this gun paper model from here: Team Fortress 2 (TF2) - Sentry Gun Free Paper Craft Download