Open solid works – go to PART DEIGN . A new designing window gets open on the screen.

Now go to SHEET METAL and select the option at the top left coroner of the window. That is " Base flange " .

Then draw a rectangle with 400 X 230 mm and just click on exit button on top right hand side of the window.

Here we have to choose the thickness of the material we are going to use for cutting our design of hopper. While extruding the plate we have to select the reveres option at the left side in the window and also we have to take care about flange length and flange position. Design the four sides of hopper in the same manner.

Then select EDGE FLANG option and then choose internal edge of the extruded plate and drag away from the plate. Follow the same step for extruding four edges of hopper.

After following all above steps, we can see the following design of hopper.

Now select FLATTEN option so that to unfold the hopper.

Now we have to save this file in Dxf formate. For that we need to choose the option below.

We can see the following image on our screen. Now we just have to click on SAVE . And we have to choose the place where we have to save the file and press ok.

I just wanted to explore this sheet metal option more. So, I have also use the drafting option in sheet metal. This option will be useful for us if we want to give our design file for fabrication to another person.

I was unknown about whatever I have design is it with correct dimension or not so, first I have cut my design file on LASER CUTTER scale down the dimensions of hopper. I was get satisfied with the dimensions and the dimensions are get conformed. Then I have cut the hopper design on PLASME CUTTER with actual dimensions.

Input power :- 3 phase

Arc reference voltage : - 96 volt

Operating current: - 25 amp plasma generator.

Torch height : - 4mm

Cutting speed : - 3350 mm/min

Operating pressure : - 6.9 bar

Working process : - Cold role cold annealing (CRCA).

First copy the .dxf file in the operating system. Then attach fast cam key to convert .dxf file to G-cod. If we are copy the file from pen drive, then make sure that we should remove the pen drive before attaching the fast cam key.

Open fast cam software and select DXF restore option from file menu. Now it will ask for the name of the file. Select the file from D-drive. Click on select option, we see the file in the window.

Now we can see the file as shown in the following image.

Now select FastPATH option from program path menu.

Then click on Start FastPATH option. Tool path is get created in the following format. Also G-cod is created which we can see at the left hand side of the screen. And then select Ok.

In this way we have convert Dxf file in G-cod. Now we can give this file directly to the plasma cutter. Because plasma cutter works with G-cod format.

Input power :- 3 phase

Arc reference voltage : - 96 volt

Operating current: - 25 amp plasma generator.

Torch height : - 4mm

Cutting speed : - 3350 mm/min

Operating pressure : - 6.9 bar

Working process : - Cold role cold annealing (CRCA).

If pressure is less than arc, thickness will increases. If current is increases then arc radius also increases Voltage is 320 volt

Kerf is the width of material (perpendicular to the torch and cut axis) removed during the plasma cutting process. Kerf is affected by three major variables.

Cutting Speed. Faster cutting speeds with other variables constant will result in a narrower kerf. The kerf will continue to narrow until loss of penetration occurs. Slower travel speeds will result in a wider kerf until loss of arc occurs.

Cutting Amperage. Increasing cutting amperage with the other two variables constant will result in a wider kerf. Continuing to increase current will widen kerf until the nozzle is destroyed. Lowering amperage will result in a narrower kerf, a more positive cut angle until penetration is lost.

Standoff. Standoff is the distance maintained between torch and work-piece after piercing (while cutting). Most modern systems use an arc voltage feedback system. Increasing the arc voltage increases the standoff distance and widen the kerf. Continuing to increase standoff will eventually lead to loss of cut. Lowering standoff will lead to a narrower kerf and even- tually loss of cut.

Before go for the cutting of actual designing on plasma cutter, I have cut the test pattern with 10mm X 10mm dimension square to find out KERF and have measure it with the help of DIGITAL VERNIER CALIPER The kerf of our plasma cutter is 1.24mm.

Following vedio have the stepwise procedure of operating plasma cutter.

After cutting the 2 dimensional designs now I have to bend it. So I have used the bending machine. Ghanashyam had helped me for bending the sheet of hopper design.

While bending the hopper, we need to bend it by taking certain parameters. That we should bend either starting or last part of the sheet. We have to place our sheet between the two parts of bending machine that one is the base part with cavity provided to give bend to the sheet metal and another is the pressing spindle which also have extruded triangular part to its end. Both of these parts are design with some defend clearance between them.

After bending my hopper looks like that. Now I have to assemble the corner edges with some plates and rivets. In the second image I have mounted on the system.

This week was all about to explore or knowledge as per our interest by using digital fabrication.

So, in this week I have used plasma cutter which is a CNC machine. Also I have learnt some more parameters related to plasma cutter while cutting designed file.

I have used solid works before this week but I have not use sheet metal option. I have use this command for designing sheet metal product.

I have also used the fast cam software for converting the file in G-cod format. Which give commands to the machine from starting to stop it.

I have also used bending machine for bending the sheet.