My Technical Report On How To Make A Spur Gear

James Carl Andrino
Mar 10, 2018
6 min read

Updated: Mar 17, 2018

INTRODUCTION

Spur Gear is the most common gear used. A spur gear is a gearwheel that has teeth on its wheel axis. Making a spur gear requires that you have the material specially the tools in making a spur gear. This report was conducted to know how the spur gear was made. It was conducted by having a project in our mechanical subject last semester and this report is intended to those who are interested in mechanical. The process was performed by the instructor before to make the product or project.

PROCESS IN MAKING A SPUR GEAR

Common Material used in making a Spur Gear

· Raw Material – the ingredient used for production.

· Measuring tool such as Vernier Caliper- Vernier Caliper is a measuring instrument used to measure outside diameter, inside diameter, and depth.

· Hand Hacksaw- is a tool that is used in cutting metal.

LATHE MACHINE OPERATION FOR THE GEAR BLANK

The first thing to do before operating a machine is to check the machine if there are parts that is not functioning well. If the machine is good then do the operation but, before doing the operation is to prepare first the tools that are being used in the operation.

Tools needed in Lathe Machine Operation:

· Measuring tools (Vernier Caliper)

· Cutting Tool (High Speed Steel) –right hand

· Twist Drill Bit (Sizes: 4mm, 7mm, 10mm, 12mm, and 14mm)

· Live Center

· Drill Chuck

· Solid Square

· Parallel Bars

· Soft Face Hammer

· Mandrel (size: 14mm diameter)

· Adjustable Wrench

After preparing the tools needed for the operation is to prepare the most important thing, which is to be safety. In order to be safe while operating the number one is to have a safety goggle. The safety goggle is the most common equipment that is used to protect our eyes from the flying metal chips that are being cut. That’s why it is so important to have this safety equipment.

The diameter needed in the figure 1 is 36mm. The needed diameter in order to get the diameter 36 is its closest diameter. In our mechanical lab the raw material has a diameter of 38mm, 40mm, 42mm, 46mm and etc. so the closer diameter to make a spur gear is 38mm which is likely presented.

The raw material is already there so the first thing to do is to cut the material. The length of the material needed is 18mm but there is an allowance needed. There is an allowance of 6mm. The length that is needed to be cut is 24mm.

After cutting the material, the next procedure is to put the material into the lathe machine and do the facing operation both sides and after the facing operation do the center drilling. The purpose of the center drilling is to have a guide of the workpiece that is being held by the chuck of the lathe machine and attached by a Live Center so that it won’t be wobble.

When the center drilling is done the next procedure is to attach a live center on the drill centered in order to support the movement of the workpiece while operating. After attaching the live center to the workpiece is the turning operation.

In the Figure 1, it shows the measurement that is needed in the turning operation is 22mm x 9mm. The 22mm represents the diameter in turning operation and the 9mm represents the length in turning operation.

After the turning operation which is the drilling operation. In the Figure 1 it shows that the inside diameter that is going to be drilled is 14mm but first it should be drilled into a small hole so that it would be easier to drill such as a big hole like 14mm. The first size of the twist drill bit that is going to used is the 4mm size, next is 7mm then 10mm, after 10mm is 12mm and the last but not the least is the 14mm size.

The next operation is the chamfering. In the Figure 1, the chamfer is labeled 1mm x45°, the 1mm represents the amount that is being cut and the 45° represents the position of the cutting tool.

After doing the chamfering, put the workpiece on the mandrel and get the 36mm diameter and after do the chamfering of both edges.

HORIZONTAL MILLING MACHINE OPERATION

Before operating in the horizontal milling machine the first thing to do is to familiar the parts of the horizontal milling machine and its function in order to know how this machine works.

The horizontal milling machine is used to cut horizontally to a workpiece. The one of the use of the horizontal milling machine is to make a spur gear. In figure 2 it shows the parts of the horizontal milling machine.

Figure 2:

THE PARTS AND FUNCTION OF THE HORIZONTAL MILLING MACHINE

1. Base: It gives support and rigidity to the machine and also acts as a reservoir for the cutting fluids.

2. Column: The column is the main supporting frame mounted vertically on the base. The column is box shaped, heavily ribbed inside and houses all the driving mechanisms for the spindle and table feed.

3. Knee: The knee is a rigid casting mounted on the front face of the column. The knee moves vertically along the guide ways and this movement enables to adjust the distance between the cutter and the job mounted on the table. The adjustment is obtained manually or automatically by operating the elevating screw provided below the knee.

4. Saddle: The saddle rests on the knee and constitutes the intermediate part between the knee and the table. The saddle moves transversely, i.e., crosswise (in or out) on guide ways provided on the knee.

5. Table: The table rests on guide ways in the saddle and provides support to the work. The table is made of cast iron, its top surface is accurately machined and carriers T-slots which accommodate the clamping bolt for fixing the work. The worktable and hence the job fitted on it is given motions in three directions:

a). Vertical (up and down) movement provided by raising or lowering the knee.

b). Cross (in or out) or transverse motion provided by moving the saddle in relation to knee.

c). Longitudinal (back and forth) motion provided by hand wheel fitted on the side of feed screw.

In addition to the above motions, the table of a universal milling machine can be swiveled 45° to either side of the centre line and thus fed at an angle to the spindle.

6. Over arm: The Over arm is mounted at the top of the column and is guided in perfect alignment by the machined surfaces. The Over arm is the support for the arbor.

7. Arbor support: The arbor support is fitted to the Over arm and can be clamped at any location on the Over arm. Its function is to align and support various arbors. The arbor is a machined shaft that holds and drives the cutters.

THE REQUIRED EQUIPMENT IN HORIZONTAL MILLING MACHINE

· Indexing head or Dividing head

· Tailstock

· Lathe dog

· T- slot nut

· Mandrel

The indexing head is used to hold the mandrel together with the tailstock and also to the lathe dog. The lathe dog is used to support the mandrel so that the mandrel will not be wobble.

The T-slot nut together with the bolt is used to hold the indexing head and the tailstock so that the both of them will not move.

The first thing to do is to set-up the indexing head and the tailstock and after lock the indexing head and the tailstock using the T-slot nut together with the bolt.

After the set-up, put the workpiece or the gear blank on the mandrel to the indexing head and the tailstock together with the lathe dog so that the workpiece will have a support.

The available hole circles on the indexing head are 16,18,20,23,29,33,40,and 49. In the figure 1 it named there the plate of the available whole circles which is the Cincinatti Plate.

In the spur gear shown in the figure 1, the number of teeth that can make is 16 teeth because of the diameter of the gear blank. The cutter number needed for the spur gear is number 2 module 2. In the figure 3, it shows there how to compute for the outside diameter, whole depth, and the crank movement.

The crank movement (CRM) defines the movement of the index plate. While operating, the whole depth that is needed to be cut is 4.33mm.

In moving the index plate, use the crank movement (CRM) which is the 2 full turns, 8 holes, in a hole circle so in the index plate, there are a lot of holes but the plate used is the cincinatti plate. After cutting the whole depth of 4.33mm turn the index plate into 2 full turns and 8 holes then repeat these process until the 16 teeth is produced.

CONCLUSION

This is the process in making a spur gear which can be process into many different ways and many different procedure. Mechanical design requires many skills. In designing problem number of gear teeth was determined. The process on how to do it was determined.

RECOMMENDATION

It is recommended that after doing the operation should do the 5’s because it is also the best way to have safety.

It is also recommended to have a safety goggles while operating and putting coolant of the cutting tool because it creates friction that’s why it is recommended to put coolant while operating also putting oil of the machines to avoid corrosion.

APPENDIX

Figure 1 and 3