The development of design method and fixtures modification using variant   approximation based on dowel pin modular fixtures can also make fixtures designeasier [2].

CAD/CAM/CAE/CAT softwares can be used as fixture synthesized method including geometric analysis, design and assembling of fixture in three dimensional mode [3-4].

Expert system has been developed for designing the fixtures which can be used as a basic guide in designing and assembling the appropriate fixtures [5].

When assembling fixture in a machining process,the work piece position,tool movement,pin/locator flexibility have to be considered so that the elements of jig and fixture will be interchangeable and reusable [6].

Designing and assembling of jig and fixture can be carried out using finite element  method, then simulated by the ANSYS software  [7].

 Carbon fiber composite has been used as the material of jig and fixture in car assembling [8].

This paper deal with the engineering design of a gang drill prototype in order to help  some small enterprises hat produce birdcage to solve their problem. Their problem was how to drill many holes in one step, how to maintain the same distance between holes, and how to maintain the holes straightness. In the past, the drilling process was  done one by one for each hole so  that the drilling process was very exhausted [9].

This gang drillig machine is equipped with jig and fixtures specially in the type of drilling jig, which control the relationship between work piece and cutting tool. Meanwhile, the fixtures in this machine is used as the clamping elements for gripping the work piece. To realize this engineering process, it would require the calculation of  the main components such as shaft, gear,bearing and spring and pin. The following equation is used for the shaft calculation[10-12]:

II. METHOD

Prototype of gang drilling machine is equipped with Jig&Fixture, is an engineered effort to increase production of the bird cage small business (see Figure3).

A. Materials Test

Materials used in this study, in determining the speed of drilling and power  requirements are teak, aluminum, brass and cast iron that have mechanical properties, such as Table 1.

B. Research Flowchart

In order to design the prototype of gang drill equipped with jig&fixture, it is necessary to have some steps as, shown in the flow chart in Figure 4.

C. Examination

In order to get a gang drill machine which is able to work properly, the testing by  variying the material and rotational speed are conducted. Therefore, the power requirements for fine drilling chisels work simultaneously are known.Five rotational speed (150rpm,250rpm,400rpmand 1450rpm) are used in the experiments while the tested materials are teak wood, aluminum, brass and cast iron. Every drilling process for certain material and rotational speed is carried out with 5(five) times iteration. To find out, how much gang drilling machine can be useful for small business in order to improving productivity, verification of drilling speed  and power requirements are performed for single chisel drilling machine with a single motor gang drill. Therefore, time difference and resources required in the drilling  process between them can be known. Tests is carried out by varying the number of chisell drill (1pieces,2pieces,3pieces,4pieces and 5pieces) and materials (teak wood,aluminum, brass and cast iron). Each test is iterated five time.

III. RESULTS AND DISCUSSION

Based on the calculations, the countershaft and the driven shaft have the dimension,  which are listed in Figure 5 and 6, respectively. Where as the specifications are given in Table 2.

Futhermore, the straight gears are used to transmit power and rotary motion between  the two shaft which are arranged parallely as shown in Figure 7 and 8. The specification of the gears are given in Table 3.