Creating a Part Profile From an External Image




About: I am an Engineering Technician with 15 years as a glorified government drafter. Another 5 years was spent drawing/programing for a company that had CNC machines. I taught AutoCAD at the local community colle...

While working on a frame and panel front desk for an apartment building lobby, I ran into a problem. The architectural drawing called for several different moldings. I thought it would be easy. I checked out the web sites and found that one Company A had an AutoCAD drawing for each molding. Company B had an Adobe PDF. Company C had a paperback book of moldings, $28 at Amazon, but no other drawings. But since we only needed a couple of shapes, the only thing they could do was to trace the samples and fax them to us.

You can see that only height and width are given for molding, because that is all builders are really concerned with. A bit of the molding face is shown to help designers.

The same procedure will work for just about anything you want to trace.

Note: This instructable is for Alibre users and assumes that you are familiar with Alibre basics. If you are not I recommend that you work through the tutorials. They are very easy to follow and will have you up to speed in no time.

Step 1: Capture the Image.

We will use Molding #261. There are several ways to save an image. I have my personal favorite, Gadwin PrintScreen is set up to allow me to drag a box around the image I want and save it as a JPG. It really doesn’t matter how you save it as long as Alibre supports it.

This is from Alibre Help: “Several popular file types are supported: JPG, GIF, TIF, BMP, DIB, RLE, EMF, WMF, PNG, JPE, JPEG, JFIF and TIFF. Alibre Design does not support JPEG 2000 or lossless JPEGs, as well as some types of TIFF files.”

Step 2: Insert an Image in a Drawing.

Open Alibre Design, select New Drawing, select Blank Sheet (A Landscape (11x8.5 inches) and check Create Empty Drawing box. Ignore Default View Scale, we will scale it later. Once the drawing is opened make sure that the dimensions are set to decimal inches. This will make it easier and more accurate to scale.

Make sure that New Sheet<1> is highlighted in the Drawing Explorer column. From the Insert menu, select Image. The Select Image dialog box appears. Browse to the saved location of the image you want to insert. Click the image’s file name. Click Open. The floating image appears in the drawing workspace and the mouse pointer has changed to a dotted crosshairs icon. Click the crosshairs icon on the drawing sheet to place the image near (but not on) the lower-left corner of the image. The lower-left corner represents the origin position on a part or assembly. This image placement will help us later.

Save the Drawing as Molding_261 (Alibre will add the file extension .AD_DRW when you click Save).

Step 3: Determing the Image Size.

The part of the molding that we care about is the profile (the gray face). If you recall your high school drafting class, the vertical and horizontal lines on the leading face of the profile are true-length lines. That means that after we have scaled the image the bottom edge will be 7/8" and the left edge will be 7/16". Then it will be straight forward to find the dimensions of the other parts.

Activate 2D sketch, and select Line. Draw a horizontal line just below the bottom line. To make it easy to see, use the crosshairs to help you. Dimension the line then exit sketch mode.

HINT: Sometimes image lines can be very wide and it is hard to decide where to begin the line. That was the case here. I had thin crosshairs and wide lines. So I chose to start my line by positioning the crosshair at the left edge of the left fuzzy vertical line and stop at the left edge of the right fuzzy vertical line. Exit Sketch mode.

Step 4: Scale the Image.

To resize the image, right-click on the image and select Scale from the pop-up menu.
The Scale dialog box appears.

Our image is bigger than we want, the profile itself tells us that Molding #261 is 7/16" high x 7/8" wide. So using the logic that a ratio of .5 / 1.0 would make our image half as big. We will put the size that we want (7/8 = .875) on the left, and the size we have (1.868) on the right, and click OK.

Reenter sketch mode draw an new line and dimension it. My line at this point was .875333. Close enough so I rounded it down to .875".

Step 5: Trace the Image.

Right Click on the white space outside of the image box and select Activate Sketch on Sheet. Trace the image profile as close as you can. Then save the drawing again.

Step 6: Copy/Paste the Image.

This is the same Copy/Paste that you have already done many times: Copy from one file, open a new file, and paste into the new file. Easy! Ready?

From the Edit menu choose Select All to highlight the lines you have just drawn (or use the Select tool). Next from the Edit menu choose Copy, then choose File menu and choose New Part. Make sure the XY plane is highlighted in the Design Editor, then from the Edit menu choose Paste.

Step 7: Make a Part.

NOTE: This is where inserting the image in the lower left portion of the drawing page comes in handy. The image will be inserted near (but not on) the origin of the part. It should show up without having to hunt it down on another part of the screen.

Before the image profile can be dimensioned or moved check to make sure there are no errant lines or points. This is easy in Alibre . From the Sketch menu select Analyze Sketch. Make sure that all of the Analyze items are checked and Click Analyze. If something pops up in the results field, you will see an red indicator square. Click Heal and it will fix the problem.

Step 8: Constrain and Dimension the Part.

The image profile appears to have parallel constraints even though we haven’t put any in, because we were careful when we traced the lines. I tried to put a perpendicular constraint in but got a message saying that it would over-constrain the profile. Ideally then all we should have to do add dimensions.

You may choose to constrain and dimension differently that I have below. I added a reference line to the arc area. Then dimensioned the amount of the top arc to show, because the arcs have the same radius but not the same length. Last, I constrained the points where the arcs join the reference line.

Save the part as Molding_261 (Alibre will add the file extension .AD_PRT when you click Save). Don’t exit yet.

Step 9: Make a Catalog Feature

In woodworking design, like other things, you will want to use parts over and over. A molding can be used in many different places. Alibre knows this and allows us to turn our part as a Catalog Feature, that can be inserted easily and used over and over, without changing the existing Part.

Highlight Sketch <1> in the Design Explorer. From the Features menu, select Save Catalog Feature. “Sketch <1>” should appear in the box. Click Save As. When the Save As dialog box appears, enter Molding_261 (Alibre will add the file extension .AD_PCF when you click Save).

Step 10: Review

Take a look at the file explorer. We have 3 new Alibre files.

Molding_261.AD_DRW is the drawing sheet that we inserted the external image into.
Molding_261.AD_PRT is the part drawing that we made from the scaled and traced image.
Molding_261.AD_PCF is the catalog feature drawing that we saved the part into.



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    7 Discussions

    Mr. INTJ

    6 years ago on Step 7

    Worked like a charm! Thank for doing this, Woodknot. I had to design an adapter for a brand A light ring and my brand B microscope. I tried measuring, but I needed a tight fit for the adapter, and the shape was not a simple one. By scanning the shape on my HP all-in-one printer, I was able to create a design, 3D print it, and got it right the first time. :-)

    owl box

    8 years ago on Introduction

    Company 'A' is Interstate Lumber Company 'B' is Dykes Company 'C' is CLC Lumber Co. Am I right? ;)

    1 reply
    woodknotowl box

    Reply 8 years ago on Introduction

    Quite frankly, I can't remember which companies we "borrowed" them from. They were from some work we had done about the time the instructable was written. It all merges together after a while.

    WOW, this was a great instructable - you are an amazing teacher!  Not only creating a catalogue part but being able to bring in and trace a jpg file, I'm impressed.  Being able to bring a jpg into Alibre drawing was what I tried years ago and also had ALibre support try to show me this.  And now I just did it.  

    With this capability I can now get anyone with a paint program to draw a vague outline and even hand dimension the sizes and email the jpg to me and I can scan it using that wonderful package that you mentioned and I have an accurate part - EXCELLENT!

    I can't believe how simple things become for me when I finally get a good teacher.  Thanks.

    This is nothing like Corel Draw - I am looking forward to the day when I can take my copy of X13 and put it all in the fire pit.  

    With this package I will finally be able to see if something is going to fit before cutting it on my machines.


    11 years ago on Introduction

    The big difference is what you can do with the design once you bring it in to Alibre. It is more than just graphics, it is a true solid that can be used to build a 3D model that can be analyzed, checked for interfering parts, have dimensions driven by equations and spreadsheets, and can output a complete material list for manufacture. We think of it as virtual woodworking. We work through an entire woodworking project in a manner similar what we would do in the workshop, and solve design issues and proportions before even cutting the first board. We can rotate the model and examine it from all angles, hide parts or make them transparent, create exploded views to assist ourselves and other with understanding the construction, create 3D PDF files that a client can view on their own computer and manipulate in 3D, and create drawings for review and approval. Cross Sections, magnified details, and isometric views are created automatically. And it is accurate, without the fudging and inaccuracies of manual drawing. And, all this information is derived quite simply from the solid model itself. When the dimensions of the model change, the drawing updates automatically and the dimensions update on the drawing as well. No more laboring over making sure all the views really reflect the design correctly, no more erasing lines that are no longer needed, and adding the new lines and dimensions. It is quite different, and a significant improvement from 2D CAD and graphics programs. It takes a bit more effort to learn, but in the end is well worth the trouble. Take if from someone that has spent their life making a living doing drafting from an age where a mechanical pencil and electric eraser was hi-tech, I will not go back to manual drawing, nor even a 2D drawing package.


    12 years ago

    This is the same method I use in CorelDraw to renew very old drawings! Takes a long time, but gives 'em quality. I oughta try CAD design someday, doesn't look much different than CorelDraw.

    1 reply

    Reply 12 years ago on Introduction

    Thanks for your comment. In many ways CAD programs are similar to CorelDraw but with a big difference. Both types of programs will allow you to do vector graphics. CAD programs are for precise design work rather than just graphics. Alibre Design has the ability to work with parametric driven models. For example: A simple 2D rectangle is 2"W x 4"H. You could dimension it like that and both dimensions are independent of each other. Or you could say that it is 2"W x (2*W). This ties the height to the width. Each time the width changes the height automatically changes with it. That may be more than you wanted to know. I think I see another Instructable.