Plouf as a first CAD exercise?
11-17-2003, 05:22 PM
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Plouf as a first CAD exercise?
Hi all, would the Plouf (http://www.rcflight.co.uk/images/Plouf-plan-web.zip) be a good plan for a first-attempt at creating a CAD file? I'd like to be able to take existing plans/kits and resize and futz around with them (hopefully sending off to a laser cutter for my parts) and thought that I should start with something relatively simple. I downloaded the free version of TurboCAD and would be doing all my CAD-work in that. I was hoping I could import the .jpg file and trace it, learning the CAD tool as I went.
thanks,
Rick
thanks,
Rick
11-17-2003, 10:14 PM
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RE: Plouf as a first CAD exercise?
I doubt you'll be able to import a JPG into the learning edition. Even the standared version 7 I have doens't do it. Instead it brings in a little copy of the icon attached to the file. Very frustrating.
I have Paintshop Pro and what I do is convert it to a .PSP file and that imports just fine.
From there you'll still have to learn to use the tools to trace over the image to create your own CAD Plouf file. The image won't do you any good as is because the parts are still all just one image.
To just play around you'd be better off downloading some DXF or DWG files from some of the plan places. Then you can use them directly.
If you persue the Plouf and need a PSP conversion PM me and include an email I can send the file to.
I have Paintshop Pro and what I do is convert it to a .PSP file and that imports just fine.
From there you'll still have to learn to use the tools to trace over the image to create your own CAD Plouf file. The image won't do you any good as is because the parts are still all just one image.
To just play around you'd be better off downloading some DXF or DWG files from some of the plan places. Then you can use them directly.
If you persue the Plouf and need a PSP conversion PM me and include an email I can send the file to.
11-17-2003, 10:54 PM
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RE: Plouf as a first CAD exercise?
Bruce, thanks for the info! Unfortunately I've run into the same problem with the only .dwg file I've tried so far (as happens, I found someone with a partially traced Plouf plan). Have you heard that the free version won't do that, or could it be just this file?
I was planning to trace the image (and in the process be forced to learn at least a small portion of the cad tools) so a .psp file sounds like it might be just what I need. my e-mail is rick.w.lindsey <at> verizon.net
-Rick
I was planning to trace the image (and in the process be forced to learn at least a small portion of the cad tools) so a .psp file sounds like it might be just what I need. my e-mail is rick.w.lindsey <at> verizon.net
-Rick
11-18-2003, 02:47 AM
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RE: Plouf as a first CAD exercise?
Rick, I'll do the PSP for you in the next day or so. I'll also do up a sort of beginner's guide to the basic tools that I rank up there as the top ten to know if you want to draw well. It's too late tonight to think that straight.... 
I can also send you a couple of my own TCW files to play with. Hope you have high speed. The total package will be a biggie!
I can also send you a couple of my own TCW files to play with. Hope you have high speed. The total package will be a biggie!
11-18-2003, 10:39 AM
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RE: Plouf as a first CAD exercise?
I took a look at the noted model A/C plan, and it don't look simple for a first project. It may be small, but difficult thereafter. There are half tones, a gap and irregular lines shown in my download. It may have been fine for publishing, but it will become a challenge for an initial CAD operator trying to replicate the work.
I would suggest something a bit more simple, having a lot more straight lines and more contrast in the image too. There are numerous A/C plans out there for free on the net in BMP or TIFF formats. A JPEG is a poor start due to the courseness when you zoom in tight. Go visit the Jo Jusko site or one of the Russian sites and there are numerous examples to attempt.
Wm.
I would suggest something a bit more simple, having a lot more straight lines and more contrast in the image too. There are numerous A/C plans out there for free on the net in BMP or TIFF formats. A JPEG is a poor start due to the courseness when you zoom in tight. Go visit the Jo Jusko site or one of the Russian sites and there are numerous examples to attempt.
Wm.
11-19-2003, 12:06 AM
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RE: Plouf as a first CAD exercise?
Yeah, I would only do the lines rather than try to totally duplicate all the features of the plan. Otherwise you'll be biting off WAY too much. You may just want to start with doing something simple like a 3 view of an Ugly Stik or something like that. Then as you learn the tools you can fill in the details. Don't be afraid to doodle.
OK, time for unca' Bruce's "Baker's Dozen TurboCAD Rulz"....
[ul][*]1- Learn to Snap. Learn what they are, how to invoke them, particularly the shortcuts, and USE them as much as possible. Only very rarely should you start or end an element without using a snap to grid, vertex, middle, center, etc. For TurboCAD this falls under the SEKE (Single Entry Keyboard Equivalent) list. I doubt I draw, move or modify more than 5% of my work without using a snap. This is not only rule #1 but it may be the most important rule as well. A CAD program sinks or swims on the basis of it's snap functions when you know what you are doing. It ensures accuracy and greatly speeds up performing accurate work. CAD programs that make this function hard to access and use should be relegated to life as a coffee table coaster.[*]2- Never draw the same thing twice. Sounds simple but sometimes you need to think about it. Tools that allow you to fullfill this tip are Mirror, Array copy (linear, radial and matrix) and Copy/Paste. When I work on a wing I'll do all the work on one side and then mirror the whole lot over. If I have to do a change I do it on one side, delete the WHOLE other side and just mirror the whole lot over again. Use the V key to snap to the ends of the center line or the G key to snap to the grid if you had the presence of mind to align your drawing to the grid lines. Only if I do a couple of simple ADDITIONS will I just mirror the additions. The wing ribs are done by drawing in ONE rib and then selecting it and using the Linear Array tool to replicate a whole set at the right spacing. Use the TAB and enter the actual numbers in at the command bar on the bottom of the screen for accuracy.[*]3- When using the selector arrow you can add or drop objects to the group of selected objects by using the shift key. Pressing SHIFT brings up a little + beside the arrow. Don't pass over the fact that there are two selector types. The normal one and the Node edit one. The node edit one is particularly handy for changing the elements of a curved line but work on all types of elements. Here again you can either drop the node freehand or with a SEKE.[*]4- Placing elements or groups of elements accuratley can be done by using the snap. But often the reference point is not where you want it. Another SEKE that is useful in this case is the D key. Pressing that while elements are selected lets you move the reference point to anwhere you want. Dropping it using yet another SEKE ensures that you put it where you want it.[*]5- Use the right mouse button a lot. It brings up the greatest option boxes at the best times. It's position sensitive too. Over the drawing it has one set. If an item is selected it has another set of options. If you right click on a tool button it opens up the Properties for that tool, line type, text formating, etc.[*]6-Always draw in full size. It's a lot easier and the computer doesn't know or care if you're asking it to make the paper the size of Manhattan. It'll still come out fine on your 8.5x11 at print time if you just set the paper that way and check the "fit to page" box. This will save you a LOT of math and make the drawing correct for later printing at Kinkos or other large plotting services.[*]7-The hard drive has LOTS of room so don't ever delete anything. Allways keep the old file until you KNOW you won't need it and even then keep it for another month. THe same thing applies for the drawing. If you want to try some aesthetic changes to a model copy the present version and paste a second copy to one side and work with that until you are sure you like the new version better. In this vein I never work with my "final" plan at first. I work with a file where there are often 3 or 5 versions of the design scattered about with wing ribs everywhere. This is my rough file where no face can be too ugly to the point where it deserves deletion. From that rough file the final choices are made and whole wings and fuselages are cut and pasted to a final presentation file. Most of us do our best work on a scratch pad where there are no rules. This rough file IS that pad when you are comfy with your CAD. Models are an art form. It's OK to create mulitple versions of your own Picasso. (What do you MEAN I can't have both wings on the same side of the fuselage...)[*]8- The Trim tool is used for lines that are interrupted by overlying elements. To make the drawing look good you want to hide the bits underneath. The Trim tool is the one for this. You start by selecting a "cutting edge". You can add additional cutting edges by using the SHIFT key. Then click on the bit that goes past the line or under the double line or between the first and second cutting edge. For example you can SELECT all the ribs (double lines) in a wing panel as cutting edges and then click on the bits between each rib's double line to eliminate the hidden bit.[*]9- The Split tool is nice for splitting a large or long element into two or more if you need to move a part away. For example you want to "lift" the cockpit canopy off a nice long single curved sailplane fuselage side view. Use the Split tool to cut the curve at the ends of the canopy and then select the canopy part along with any formers or other parts and move it up as desired.[*]10-The Grid comes in handy for a lot of things and as a quick ruler that is always there. I like to set up the drawing so the grid is on and it shows at the 1/2 inch spacing with a heavier line at the 1 inch lines. I actually bring up the Grid Properties and set it to 1/4 inch and then set the frequency to 2 so that the lines still only show at the 1/2 and 1 inch marks.[*]11-TurboCAD let's you select line widths. Ignore this for the most part until the final stages of a drawing. Using that function to early actually draws the line thicker on the page and as you zoom in and out the line is thicker or thinner. It also make snapping to the line difficult as it treats it as a filled double line and you'll end up snapping to a corner rather than the center of the line as you intended. To make the lines thicker FOR THE PRINT ONLY go into the Options/Drawing Setup/Display and set the box at the bottom of the page where it says "Device pen width when zero value is used" to a new value. I find I like .010 for most 8.5 by 11 and increase it to .015 for vellum prints where I'll be making blackline prints from them later. Other line widths can be set to thicker by select and command as a final step. But save the last "zero width" drawing for reference because it's cumbersome to re-zero them later I found.[*]12-After a while you'll get to know how you want your drawing options set. At that point open a new drawing and set everything for one last time. Be sure to get it all. The text size and style, default line width, units of measurement, etc. Then save it in the Templates directory as a TCT template file with your name or Models or something like that so you can find it when starting a new drawing. You can also set up a paper size for little sketches if you wish with a border and nice title box. That's assuming that the stock ones aren't enough for you. There's dozens with the standard version of the software.[*]13- Line types. Just play with them. For curves my personal preference is for the Spline over the Bezier just because I find it easier to get a smooth form. For times where the curve line vertex MUST land on a specific point then use the Bezier and just learn to get along with the fine tuning (node edit mode). For edge on views of balsa the double line works great and allows for ideal and fast trimming as noted above. A trick to making curved sheeting lines is to form the curve baseline using the Spline or Bezier tool. Then right click the double line selection box to bring up the Properties and click on the Right or Left reference. Select the Mulitpoint Double Line and lay down a close spaced set of vertices using the curved baseline and the Near SEKE to snap the double line down onto the curved line. Yes these ARE all little tangent segments rather than a smooth line but if you keep the segments short where the curve is tight and not too far apart where it isn't then the error is lost in the line width during printing. It's cheating but it works and is fast.
[/ul]
THAT should keep you off the streets for a few nights.... My fingers are tired now....
Any other TurboCAD types that want to toss in an idea or two please feel free.
OK, time for unca' Bruce's "Baker's Dozen TurboCAD Rulz"....
[ul][*]1- Learn to Snap. Learn what they are, how to invoke them, particularly the shortcuts, and USE them as much as possible. Only very rarely should you start or end an element without using a snap to grid, vertex, middle, center, etc. For TurboCAD this falls under the SEKE (Single Entry Keyboard Equivalent) list. I doubt I draw, move or modify more than 5% of my work without using a snap. This is not only rule #1 but it may be the most important rule as well. A CAD program sinks or swims on the basis of it's snap functions when you know what you are doing. It ensures accuracy and greatly speeds up performing accurate work. CAD programs that make this function hard to access and use should be relegated to life as a coffee table coaster.[*]2- Never draw the same thing twice. Sounds simple but sometimes you need to think about it. Tools that allow you to fullfill this tip are Mirror, Array copy (linear, radial and matrix) and Copy/Paste. When I work on a wing I'll do all the work on one side and then mirror the whole lot over. If I have to do a change I do it on one side, delete the WHOLE other side and just mirror the whole lot over again. Use the V key to snap to the ends of the center line or the G key to snap to the grid if you had the presence of mind to align your drawing to the grid lines. Only if I do a couple of simple ADDITIONS will I just mirror the additions. The wing ribs are done by drawing in ONE rib and then selecting it and using the Linear Array tool to replicate a whole set at the right spacing. Use the TAB and enter the actual numbers in at the command bar on the bottom of the screen for accuracy.[*]3- When using the selector arrow you can add or drop objects to the group of selected objects by using the shift key. Pressing SHIFT brings up a little + beside the arrow. Don't pass over the fact that there are two selector types. The normal one and the Node edit one. The node edit one is particularly handy for changing the elements of a curved line but work on all types of elements. Here again you can either drop the node freehand or with a SEKE.[*]4- Placing elements or groups of elements accuratley can be done by using the snap. But often the reference point is not where you want it. Another SEKE that is useful in this case is the D key. Pressing that while elements are selected lets you move the reference point to anwhere you want. Dropping it using yet another SEKE ensures that you put it where you want it.[*]5- Use the right mouse button a lot. It brings up the greatest option boxes at the best times. It's position sensitive too. Over the drawing it has one set. If an item is selected it has another set of options. If you right click on a tool button it opens up the Properties for that tool, line type, text formating, etc.[*]6-Always draw in full size. It's a lot easier and the computer doesn't know or care if you're asking it to make the paper the size of Manhattan. It'll still come out fine on your 8.5x11 at print time if you just set the paper that way and check the "fit to page" box. This will save you a LOT of math and make the drawing correct for later printing at Kinkos or other large plotting services.[*]7-The hard drive has LOTS of room so don't ever delete anything. Allways keep the old file until you KNOW you won't need it and even then keep it for another month. THe same thing applies for the drawing. If you want to try some aesthetic changes to a model copy the present version and paste a second copy to one side and work with that until you are sure you like the new version better. In this vein I never work with my "final" plan at first. I work with a file where there are often 3 or 5 versions of the design scattered about with wing ribs everywhere. This is my rough file where no face can be too ugly to the point where it deserves deletion. From that rough file the final choices are made and whole wings and fuselages are cut and pasted to a final presentation file. Most of us do our best work on a scratch pad where there are no rules. This rough file IS that pad when you are comfy with your CAD. Models are an art form. It's OK to create mulitple versions of your own Picasso. (What do you MEAN I can't have both wings on the same side of the fuselage...
)[*]8- The Trim tool is used for lines that are interrupted by overlying elements. To make the drawing look good you want to hide the bits underneath. The Trim tool is the one for this. You start by selecting a "cutting edge". You can add additional cutting edges by using the SHIFT key. Then click on the bit that goes past the line or under the double line or between the first and second cutting edge. For example you can SELECT all the ribs (double lines) in a wing panel as cutting edges and then click on the bits between each rib's double line to eliminate the hidden bit.[*]9- The Split tool is nice for splitting a large or long element into two or more if you need to move a part away. For example you want to "lift" the cockpit canopy off a nice long single curved sailplane fuselage side view. Use the Split tool to cut the curve at the ends of the canopy and then select the canopy part along with any formers or other parts and move it up as desired.[*]10-The Grid comes in handy for a lot of things and as a quick ruler that is always there. I like to set up the drawing so the grid is on and it shows at the 1/2 inch spacing with a heavier line at the 1 inch lines. I actually bring up the Grid Properties and set it to 1/4 inch and then set the frequency to 2 so that the lines still only show at the 1/2 and 1 inch marks.[*]11-TurboCAD let's you select line widths. Ignore this for the most part until the final stages of a drawing. Using that function to early actually draws the line thicker on the page and as you zoom in and out the line is thicker or thinner. It also make snapping to the line difficult as it treats it as a filled double line and you'll end up snapping to a corner rather than the center of the line as you intended. To make the lines thicker FOR THE PRINT ONLY go into the Options/Drawing Setup/Display and set the box at the bottom of the page where it says "Device pen width when zero value is used" to a new value. I find I like .010 for most 8.5 by 11 and increase it to .015 for vellum prints where I'll be making blackline prints from them later. Other line widths can be set to thicker by select and command as a final step. But save the last "zero width" drawing for reference because it's cumbersome to re-zero them later I found.[*]12-After a while you'll get to know how you want your drawing options set. At that point open a new drawing and set everything for one last time. Be sure to get it all. The text size and style, default line width, units of measurement, etc. Then save it in the Templates directory as a TCT template file with your name or Models or something like that so you can find it when starting a new drawing. You can also set up a paper size for little sketches if you wish with a border and nice title box. That's assuming that the stock ones aren't enough for you. There's dozens with the standard version of the software.[*]13- Line types. Just play with them. For curves my personal preference is for the Spline over the Bezier just because I find it easier to get a smooth form. For times where the curve line vertex MUST land on a specific point then use the Bezier and just learn to get along with the fine tuning (node edit mode). For edge on views of balsa the double line works great and allows for ideal and fast trimming as noted above. A trick to making curved sheeting lines is to form the curve baseline using the Spline or Bezier tool. Then right click the double line selection box to bring up the Properties and click on the Right or Left reference. Select the Mulitpoint Double Line and lay down a close spaced set of vertices using the curved baseline and the Near SEKE to snap the double line down onto the curved line. Yes these ARE all little tangent segments rather than a smooth line but if you keep the segments short where the curve is tight and not too far apart where it isn't then the error is lost in the line width during printing. It's cheating but it works and is fast. [/ul]
THAT should keep you off the streets for a few nights....
My fingers are tired now.... Any other TurboCAD types that want to toss in an idea or two please feel free.
11-19-2003, 08:56 AM
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RE: Plouf as a first CAD exercise?
ORIGINAL: BMatthews
OK, time for unca' Bruce's "Baker's Dozen TurboCAD Rulz"....
OK, time for unca' Bruce's "Baker's Dozen TurboCAD Rulz"....
The Meet 2 Lines, Parallel Line and Vector Copy tools are up there near the top of my favorites list as well.
Also don't forget about Layers. I like to put the normal drawing entities on layer "0", the border and title box on "1", make separate layers named for "Hidden Lines", "Text", "Leaders" and for my stuff, a special "CNC" layer for all the CNC toolpaths which are offset by 1/2 the router bit diameter.
11-19-2003, 02:29 PM
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RE: Plouf as a first CAD exercise?
Bruce, thanks for all the tips! Hopefully I'll start to pick up the various tools quickly... several of them (the trimming thing in particular) are things I had been wondering to myself, "err, how on earth am I going to do that?".
Dickeybird, how hard is it to generate that CNC layer? I was wondering if I should even worry about laser-kerfs, since the main reason I want to create CAD files is for a laser-cutter. Can I generate my true-to-plan layer, then auto-magically shift lines around by 1/2 the kerf, or do I have to trace everything again, this time just outside my true-to-plan layer?
thanks,
Rick
Dickeybird, how hard is it to generate that CNC layer? I was wondering if I should even worry about laser-kerfs, since the main reason I want to create CAD files is for a laser-cutter. Can I generate my true-to-plan layer, then auto-magically shift lines around by 1/2 the kerf, or do I have to trace everything again, this time just outside my true-to-plan layer?
thanks,
Rick
11-19-2003, 06:43 PM
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RE: Plouf as a first CAD exercise?
Rick, I'm not sure 'bout laser kerfs....Coosbay Lumber could answer that one. I suspect that they have about a .003" - .005" kerf which shouldn't be enough to worry about; especially when you consider that balsa expands & contracts with humidity changes. My router has a 1/16" carbide bit (actually the kerf is .055", go figure!) and I have to compensate for that. I draw a parallel line in red, on a separate layer, .0275" over from all the existing lines. I'm thinking with a laser you don't have to worry about it.
