A PRESENTATION ON :

3-d PRINTER

By:

Meemohak Patel (06 DME 202)

Dhaval Bhavsar (07 DME 304)

• Imagine of a future scene that America is at war in some other country and its one of the rotor type helicopter is hit by enemy artilleries.• As a result of the hit, the gear situated in the gear box of the rotor gets damaged and the pilot has to do an emergency landing on the enemy land where it cannot stay out of sight for long time.• To airborne the helicopter once again a new gear has to be fitted. and it is impossible to obtain a new gear from the enemy country.• Still the pilot of the helicopter is not worried at all !!!• He immediately connects to the manufacturer of the helicopter in America via satellite communication and briefs them the situation.• Immediately the pilot receives the 3-d image of the gear generated through CAD on to his computer screen.• Now the pilot connects the computer with a special type of printer, which generates a 3-d gear. The pilot fits it in the gear box and takes off easily and safely.

• This printer uses a metallic powder instead of ink and it also takes into consideration the third dimension that is depth along with length and width enabling it to print Three Dimensional Parts.

• If you think that this futuristic scene is not possible then think once again as American scientist Charles W. Hal did successful trials in the field of 3-d printing way back in 1984.

• In order to research and develop further in this direction, he established 3-d Systems named company.

• For printing 3-d objects, Charles was worried about the third dimension of depth. Therefore he thought of printing the object layer by layer.

• For example consider a square cube which is to be produced by 3-d printing.

• Now cut the block into various slices with the help of computer programme and define length width and depth of each slice.

• Now feed this data to the 3-d printer which prints each and every slice keeping it on one another in the form of layers.• Summation of all these layers produces the required block.

• First trials were carried out on plastic products, which got fused together on exposure to ultra-violet rays.

• The process of 3-d printing is similar to that of 2-d printing. In 3-d printing the printer head consist of nozzle. The difference is that the nozzle instead of ink, releases polymer, ceramic material, cellulose, metallic powder.

• First a layer similar to the aluminum foil is made, after that the platform moves down.• printing head releases metallic powder and the laser fuses them together along with the first layer.• In this way second, third fourth layers etc are created.

There are two methods for 3-d printing:

Method 1:

• Suppose we have to make the letter E with the help of 3-d printing.• The printing head as required by the design will release metallic powder with consideration of length and width. • It also stops wherever necessary and then again starts. The platform takes care of the depth.

Method 2:

• This method was developed by MIT.• In this method instead of nozzle, roller is used for laying powder. The function of nozzle is to spray adhesive material.• Once the powder sticks with the adhesive material, the piston below the platform takes it downwards and then another layer of powder is spread.

• The part is hidden inside the powder and when adhesive and powder sticks completely with each other, the part can be obtained.• The remaining powder where adhesive is not applied, falls down and can be used again for printing purpose.

APPLICATION :

• 3-d printing was used when NASA scientist were in need of 50 different sized special plastic boxes for their international space station.• Making the boxes by plastic moulding was costly as well as time consuming as they had to prepare 50 different dyes.• So they used 3-d printer and today these boxes are being used in the space station.

• American aircraft carriers carry a variety of equipments and instruments ranging from engines, air-conditioners to catapaults and compressors. There are other different parts also.• Sometimes there is an emergency need of a part in the middle of ocean.• Therefore the American Navy has provided 3-d printers on the carriers.

• American Boeing company has manufactured F-18 Hornet named fighter aeroplane. In order to reduce cost there are almost 100 parts whose dye has not been prepared and are made by 3-d printing.• The Air force does not keep a stock of such parts but prepares whenever necessary.

LIMITATION :

• The limitation is that, the 3-d printing of plastics and polymers is possible and successful but printing with metallic powder is difficult and the resulting strength of the product is not as per the requirements.

ADVANTAGES :

• Alterations in the design becomes easy and less costly.• It very useful when there is an urgent need of the part for some critical operation.• Cost of dyes and machining is reduced or eliminated.

THANK YOU.