Sheet Metal Guy Blog

18 Dec 2007   03:56:20 pm
Sheet Metal Guy Announces New Industry Directory
Sheet Metal Guy, LLC just announced its new Industry Directory, a great new resource for the sheet metal industry! The most comprehensive resource for businesses in the metal forming, fabricating, and welding industries. We provide decision makers with a clear and informative list of companies whom supply new equipment, tooling, and consumables to the industry. “We get calls and email every day asking about CNC punch presses, lasers and other machinery. Some are looking for spare parts others want new equipment or supplies. The Industry Directory will help these people find what they need quicker,” said Joe Bucalo, president and Sheet Metal Guy, LLC. Next time you are looking for a new supplier, look here first. The directory is an invaluable resource to help find the contact information you are looking for and help others find you. A part of the Sheet Metal Guy website, you can find the directory online at: http://www.sheetmetalguy.com/directory The Industry Directory continues to expand as new resources are being added daily. Company listings are free for qualified suppliers.
		Category : AutoCAD | Posted By : SheetMetalGuy | Comments[151] | Trackbacks [4006]
25 Jul 2007   12:08:27 pm
Unfolding the Rectangle to Round Transition
I promised to show you how to unfold the transition we drew in the last article. Well here it is. But it is not easy. I must tell you that if you have a number of parts to be unfolded or you make these types of parts on a regular basis, it is best to invest in a good unfolding program that works with your CAD system. ProFold is an excellent one and works well with AutoCAD. In fact, you can also get the utility program, API_Shapes which will draw the transition and several other common part shapes for you. Using both of these programs you can model your transitions and unfold them in a less than two minutes. How much time have you already wasted trying to figure out just one simple transition or cone? The method used here is for very thin material, since it does nothing to account for the material thickness or bend deductions. Start by splitting your screen into two viewports. I prefer the Vertical split so I can see the 3d model in the left viewport and the flat pattern in the right viewport. You will now draw each section of the transition in the X-Y plane by measuring the length of the lines and drawing circles to find the locations for these lines in the flat pattern. A good starting location is the long side of the rectangle opposite of the split line. You know the length of the bottom line. It is the length of the rectangle (12). In the lower viewport, draw a horizontal line of this length. I drew mine about 20 above the top view of the transition. This keeps the flat out of the 3d view of the transition. Next measure the distance in the left viewport from either end of this line to the connecting point on the circle. I used the ‘Dist’ command. In the right viewport, draw a circle with the center point at one end of the horizontal line and a radius equal to the distance you just measured. Do the same at the other end of the horizontal line. Now draw a line from the end of the horizontal line to the point where the two circles intersect. Do the same from the other end of the horizontal line. Erase the circles. This will help to keep your work area clean and eliminate some confusion. To draw the next segment on each side of the flat, you will need the length of the 16 segments around the circle (polygon) in the 3d view. They are all equal, so you only have to do this once and remember the answer. You can cut and paste it. In fact having Notepad or Wordpad open to paste the lengths into is a good technique since they do repeat. In the flat pattern, or right viewport, draw a circle with the center at the top of the triangle and a radius equal to the polygon segments you just measured. Then measure the next bend line in the 3d model and draw a circle in the flat pattern using the lower corner as the center point and of course the radius is the length you just measured. Do this on both sides of the flat. Now create lines from the lower corners to the intersection of the circles. And repeat for each of the five lines in the 3d model based on the corners we are working on. Time to draw the ends of the transition in the flat. Using the radius of the last line segment, draw a circle with the center at the top (not the bottom) of the last line. Then draw a circle with the center at the bottom point and the radius equal to the width (5) of the transition. Draw the bottom edge line of the transition from the end of the horizontal line to the intersection of the circles. And another line from the far end of this line to the top of the flat pattern. You will now work lines from this new corner. The steps are the same, though, so draw the small circle at the top. Measure the next line. Draw the larger circle and fill in the line. Again repeat these steps for each of the five lines from this corner and don’t forget the other side of the flat pattern. Finally, the last flange coming around to the split or seam. Measure the length from the corner to the split line at the base of the transition. It should be 6, half of the length of the part. This will be one of the circles. Then measure the length of the split line. This will be used for the other circle. Draw the last lines, erase the circles, and your done. I told you it would be easier to buy a program to do this for you.
		Category : AutoCAD | Posted By : SheetMetalGuy | Comments[140] | Trackbacks [8726]
13 Jul 2007   03:42:38 pm
Modeling a transition in AutoCAD
Creating a 3D model of a rectangle to round transition is easier than most think. Let’s try it. Start by creating a rectangle of the desired size (use the ‘Line’ command), let’s use 12 x 5 for this example. To keep the math easy, use 0,0 for the first corner point. Then key-in the other corner as the size of the rectangle. Select the ‘Rectangle’ command from the Draw menu. Type the following coordinates at the command prompt: 0,0 12,5 ‘Zoom Extents’ to display the rectangle. Now for the round end of the transition! Actually we won’t draw it round, but will use a ‘Polygon’ command to make 16 segments around the circle. The number of segments should be a multiple of 4. The radius will be specified as a Polar Coordinate to also tell AutoCAD the rotation of the polygon. We want a point at 0, 90, 180 and 270 degrees. To calculate the angle, divide 180 by the number of segments or sides. So a 12 sided polygon would use a rotation value of 15. Pull down the Draw menu and select ‘Polygon’. Enter number of sides: 16 Specify center of polygon or [Edge]: 6,2.5,10 Enter an option [Inscribed in circle/Circumscribed about circle]: C Specify radius of circle: @3<11.25 This creates a polygon with a diameter of 6 at the center of the rectangle. The height of the transition is 10. Therefore the Z value for the center point is 10. If the round is to be offset from the center of the rectangle, add the offset values to the X and Y of the Polygon center location. Time to create the bend lines! Make sure the ‘Osnap’ includes ‘Endpoint’. Then create lines connecting the points of the polygon to the corners of the rectangle. Look at my picture as a guide. You should have 20 bend lines. Almost done, you still need a seam where the edges of the sheet metal will meet. If the transition is to be made in two pieces, there will be two seams. Create one more line from the polygon to the ‘Midpoint’ of the long edge of the rectangle. You may need to adjust your ‘Osnap’ for this. From the View menu, choose ‘3D Views’, ‘SW Isometric’ to switch to an isometric view of the model. You should now have a 3D model of your Rectangle to Round transition. But that is the easy part. What you really want is the flat pattern layout, right? Well I am saving that for next time.
		Category : AutoCAD | Posted By : SheetMetalGuy | Comments[129] | Trackbacks [3804]
13 Jun 2007   03:36:41 pm
Creating an Obround or Slot in AutoCAD
As you already know, the Fillet command is a great tool to quickly trim/extend two entities to meet and eliminate any gap between them. Just set the radius value to zero and pick the two items. But the Fillet command is also a great way to create an obround shape or slot as some people call it. Start by drawing a line the length of the obround. Then copy this line parallel to itself by the width of the obround. Now it is time for the Fillet command. Start the Fillet command and don’t worry about the radius. Just pick the two lines. Since they are parallel and will never intersect, the Fillet command creates a 180 degree arc to connect the lines. The radius of the arc is ½ the distance between the lines. Now do it again at the other end of the lines. That is certainly a lot easier than drawing circles with tangent lines and then trimming everything.
		Category : AutoCAD | Posted By : SheetMetalGuy | Comments[84] | Trackbacks [4528]
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