09-12-2012, 11:51 AM
Hi,
I've just spent a while on another forum and rather than update my notes I'll simply add them in full here and hope the story is useful to other CAD novices.
CAD is extremely difficult to learn from scratch without a tutor; CAD programs can even put a novice off right from the start as it takes a degree just to size the paper. EMS CAD fortunately is automatically sized at A4 at least it is on my computer allowing me to go directly to drawing. The following story relates to EMS CAD and I sincerely hope it encourages others to stick with it.
I could have easily gone into the garage and fabricated the welding jig shown in the pictures below; in fact I didn't even want such a jig. A friend mentioned he was planning on making a new wrought iron fence of a very simple design so I thought I would try to design and then draw a welding jig just for the CAD practice. The fence was simply two rails; one top; one bottom with either square or round section uprights. These uprights would require accurate positioning abutting the rails whilst allowing access for arc welding.
The jig design is very basic and the jig would cost extremely little to make it being nothing more than short lengths of the wrought iron rail section and a short length of 1" angle iron welded together.
I added a "dogs leg" which would allow full welding access. The jig would be secured in position using two clamps; one to secure it to the rail the other to secure the upright. Not too taxing a design but it took a bit of thought and drawing it using EMS CAD would give me much needed practice.
I then spent a day and a half of total frustration whilst I tried everything I could possibly think of in trying to convert my thoughts into a drawing. Eventually I succeeded in drawing the angle iron and backing support as a drawing and also the dogs leg section in another drawing; both looked excellent in 3D. The biggest problem though was in trying to join the two parts together. I simply could not do it and although I know my computer graphics are old fashioned my ignorance of all things CAD wasn't helping. I could have walked away from CAD forever at this point but unlike the other CAD programs I have used I was actually making slow progress with EMS; I had the two drawings and could even view them in 3D.
In EMS CAD material and machine has to be selected which is very easy; the problem I faced was in choosing the correct machine? I tried "Weld" I tried "bend" and I tried "Auto". I struggled for hours using each and found my lack of progress to be most frustrating; messages kept popping up saying lines must not overlap each other; nudge the offending highlighted line away. I tried this and each time another message followed and if I did as instructed the drawing fell apart; it is extremely important to keep "Saving" allowing the last saved stage of the drawing to be displayed so everything is not lost; selecting on the keyboard Ctrl and "Z" together will step back each time if a mistake or change needs to be made to the drawing.
I was trying to draw as I would make; this is how I always did technical drawing using drawing instruments on a drawing board. I was drawing each separate section of the jig then trying to join them together using "Intersect" and "Group". This worked OK but I could not align the two drawn sections in order to join them together. Other than the "Top" view all I could see in the other 2D views was single rectangles; viewing in 3D brought them to life but drawing on the 3D image isn't possible so once I reverted back to 2D I lost track of which side I was trying to work on; I thought I would end up with steam coming out of my ears.
Time was slipping by at an alarming rate. I then remembered Barry's advice regarding drawing a border. I had been drawing in "Space". A border didn't help me out in this instance although another comment made by Barry suddenly struck home in a blinding flash of inspiration. (one has first to understand the logic used by the originators of the software).
I had been thinking of the sections of the jig as being individual pieces of steel and steel costs a lot of money so waste has to be avoided like the plague. Adding to this I was trying to join these pieces together which was a long tedious process for me as a CAD novice. A single border didn't help but what about a 3D border? I had been drawing in 3D but only thinking in 2D and this was causing me lots of trouble.
In 2D the length and height are used (X & Y) and I selected the "square tool" drawing a random square on the page clicking once at the start then moving the mouse a bit and clicking again; this set the random sized square on the page as a 2D drawing. Now I adjusted the dimensions in the top tool bar boxes for length; height and depth (X;Y;Z) giving me a rectangular shaped block when viewed in 3D; this by the way is dead easy to do and only takes seconds. Now by clicking on one of the lines I could click on "Line" and select machine at the top tool bar. This time though I selected "injection moulding".
I could totally ignore waste as this waste was fictional and would cost absolutely nothing. The reason I say this is that I could now very easily draw lines in any of the views and as long as the lines joined I could select "Air inside" viewing in 3D I had punched a hole right through the block; once I grasped this everything dropped into place and I completed the drawing in less than 15 minutes. I could now do it in much less time after doing it once.
To expand a bit on this; A number of views are available with "Top" being default. If a solid block of material is drawn and can be viewed as a block in 3D then by selecting the view (top;bottom; left etc.) the block can be modified as though you were cutting lumps out of a block of cheese; the area is selected by drawing lines for length and breadth and although I selected "air inside" the "Z" setting can be adjusted to any desired depth but be careful because plus and minus are active; it's possible to add the shape like a patch rather than to remove it; default is plus or positive so try using the minus sign in front of the Z dimension. Strange at first but without the program doesn't know if you wish to add or remove. (air inside which is a wonderful term punches the hole shape right through).
The relief I felt was staggering; I had struggled for so long trying to work the CAD program as I would think but my thinking was not in line with the CAD creators logic. Boy I can be thick but I make up for this by being downright stubborn.
I can now not only draw in 3D but also think in 3D and this is so important whilst never being explained in detail whilst I've read about and watched videos of CAD.
I've moved a huge step forward and am now rapidly gaining confidence in CAD. the day and a half I spent playing around on this one simple drawing could be considered a total waste of my time but is it? During this time I learned a great deal and became quicker at selecting tools; going back to change something; retrieving the drawing because I had saved it; selecting material and machine in fact I learned a great deal and yes it was absolutely frustrating and irritating but well worth it in the end. Thanks Barry for supplying the spark which fired up my imagination.
I hope this story does help other novices because it isn't really about how to draw but the reasoning behind why I wanted the drawing and how I went about it. If you want to learn CAD then please throw your pencil and paper out of your mind because CAD is a totally different technique but once the basics are grasped what a whole new world opens up. The drawing below shows little detail and looking at it the drawing gives no indication as to what it is supposed to be but the 3D image selected in EMS of the same drawing makes a tremendous difference.
Kind regards, Col.
I've just spent a while on another forum and rather than update my notes I'll simply add them in full here and hope the story is useful to other CAD novices.
CAD is extremely difficult to learn from scratch without a tutor; CAD programs can even put a novice off right from the start as it takes a degree just to size the paper. EMS CAD fortunately is automatically sized at A4 at least it is on my computer allowing me to go directly to drawing. The following story relates to EMS CAD and I sincerely hope it encourages others to stick with it.
I could have easily gone into the garage and fabricated the welding jig shown in the pictures below; in fact I didn't even want such a jig. A friend mentioned he was planning on making a new wrought iron fence of a very simple design so I thought I would try to design and then draw a welding jig just for the CAD practice. The fence was simply two rails; one top; one bottom with either square or round section uprights. These uprights would require accurate positioning abutting the rails whilst allowing access for arc welding.
The jig design is very basic and the jig would cost extremely little to make it being nothing more than short lengths of the wrought iron rail section and a short length of 1" angle iron welded together.
I added a "dogs leg" which would allow full welding access. The jig would be secured in position using two clamps; one to secure it to the rail the other to secure the upright. Not too taxing a design but it took a bit of thought and drawing it using EMS CAD would give me much needed practice.
I then spent a day and a half of total frustration whilst I tried everything I could possibly think of in trying to convert my thoughts into a drawing. Eventually I succeeded in drawing the angle iron and backing support as a drawing and also the dogs leg section in another drawing; both looked excellent in 3D. The biggest problem though was in trying to join the two parts together. I simply could not do it and although I know my computer graphics are old fashioned my ignorance of all things CAD wasn't helping. I could have walked away from CAD forever at this point but unlike the other CAD programs I have used I was actually making slow progress with EMS; I had the two drawings and could even view them in 3D.
In EMS CAD material and machine has to be selected which is very easy; the problem I faced was in choosing the correct machine? I tried "Weld" I tried "bend" and I tried "Auto". I struggled for hours using each and found my lack of progress to be most frustrating; messages kept popping up saying lines must not overlap each other; nudge the offending highlighted line away. I tried this and each time another message followed and if I did as instructed the drawing fell apart; it is extremely important to keep "Saving" allowing the last saved stage of the drawing to be displayed so everything is not lost; selecting on the keyboard Ctrl and "Z" together will step back each time if a mistake or change needs to be made to the drawing.
I was trying to draw as I would make; this is how I always did technical drawing using drawing instruments on a drawing board. I was drawing each separate section of the jig then trying to join them together using "Intersect" and "Group". This worked OK but I could not align the two drawn sections in order to join them together. Other than the "Top" view all I could see in the other 2D views was single rectangles; viewing in 3D brought them to life but drawing on the 3D image isn't possible so once I reverted back to 2D I lost track of which side I was trying to work on; I thought I would end up with steam coming out of my ears.
Time was slipping by at an alarming rate. I then remembered Barry's advice regarding drawing a border. I had been drawing in "Space". A border didn't help me out in this instance although another comment made by Barry suddenly struck home in a blinding flash of inspiration. (one has first to understand the logic used by the originators of the software).
I had been thinking of the sections of the jig as being individual pieces of steel and steel costs a lot of money so waste has to be avoided like the plague. Adding to this I was trying to join these pieces together which was a long tedious process for me as a CAD novice. A single border didn't help but what about a 3D border? I had been drawing in 3D but only thinking in 2D and this was causing me lots of trouble.
In 2D the length and height are used (X & Y) and I selected the "square tool" drawing a random square on the page clicking once at the start then moving the mouse a bit and clicking again; this set the random sized square on the page as a 2D drawing. Now I adjusted the dimensions in the top tool bar boxes for length; height and depth (X;Y;Z) giving me a rectangular shaped block when viewed in 3D; this by the way is dead easy to do and only takes seconds. Now by clicking on one of the lines I could click on "Line" and select machine at the top tool bar. This time though I selected "injection moulding".
I could totally ignore waste as this waste was fictional and would cost absolutely nothing. The reason I say this is that I could now very easily draw lines in any of the views and as long as the lines joined I could select "Air inside" viewing in 3D I had punched a hole right through the block; once I grasped this everything dropped into place and I completed the drawing in less than 15 minutes. I could now do it in much less time after doing it once.
To expand a bit on this; A number of views are available with "Top" being default. If a solid block of material is drawn and can be viewed as a block in 3D then by selecting the view (top;bottom; left etc.) the block can be modified as though you were cutting lumps out of a block of cheese; the area is selected by drawing lines for length and breadth and although I selected "air inside" the "Z" setting can be adjusted to any desired depth but be careful because plus and minus are active; it's possible to add the shape like a patch rather than to remove it; default is plus or positive so try using the minus sign in front of the Z dimension. Strange at first but without the program doesn't know if you wish to add or remove. (air inside which is a wonderful term punches the hole shape right through).
The relief I felt was staggering; I had struggled for so long trying to work the CAD program as I would think but my thinking was not in line with the CAD creators logic. Boy I can be thick but I make up for this by being downright stubborn.
I can now not only draw in 3D but also think in 3D and this is so important whilst never being explained in detail whilst I've read about and watched videos of CAD.
I've moved a huge step forward and am now rapidly gaining confidence in CAD. the day and a half I spent playing around on this one simple drawing could be considered a total waste of my time but is it? During this time I learned a great deal and became quicker at selecting tools; going back to change something; retrieving the drawing because I had saved it; selecting material and machine in fact I learned a great deal and yes it was absolutely frustrating and irritating but well worth it in the end. Thanks Barry for supplying the spark which fired up my imagination.
I hope this story does help other novices because it isn't really about how to draw but the reasoning behind why I wanted the drawing and how I went about it. If you want to learn CAD then please throw your pencil and paper out of your mind because CAD is a totally different technique but once the basics are grasped what a whole new world opens up. The drawing below shows little detail and looking at it the drawing gives no indication as to what it is supposed to be but the 3D image selected in EMS of the same drawing makes a tremendous difference.
Kind regards, Col.
Happiness is a wreck of a cabinet to restore.
