View Full Version : Corel tracing for templates - Help?

Dave Yanke
11-20-2008, 6:34 PM
I have tried and tried to use the trace tool to no avail and am looking for help or possibly a tutorial that will help.

I have read about people scanning items to create templates for engraving. I have a pen (from laserbits) that I want to create a template for. I scan it and then start to fight with Trace and PowerTrace in Corel. It never gets all of the background and I end up either editing pixels or printing the scan, taking a razor and tracing the image, re-scanning and doing a fill. It is the shadow it the sacn that causes me the headaches.

Since I need to do other templates like this, I really want to figure a way to master this. I have attached on of the scan. Can someone point me in the right direction? The whole "give a man a fish..." quote applies here.

Mike Mackenzie
11-20-2008, 6:45 PM

Try one of these One of them should work cut them out of cardboard first then cut it out of acrylic.

Frank Corker
11-20-2008, 8:57 PM
Dave, your scan is about 4 times too big. You needed to scan it at 300 dpi which would have given you the exact size. Import the image into Corel and then use the polyline tool to click your way around the picture.

Assuming that the CD disc at the bottom of your image is 5.5 inches, then the attached template will be perfect for your pens. Open this with Corel and you will see I have left the shape around the image of the pen as well as created 15 placements for the pens to drop into. To engrave text select the writing then choose which size you want the font to be.

I suggest you see it visually by looking at the one which still has the image on it double clicking the writing, resize accordingly. When you are satisfied, copy and paste into the 15 placements.

Joe Pelonio
11-20-2008, 9:13 PM
An easier way to make jigs is instead of running trace, to use a create shape tool to outline the scanned image, then convert to curves and use node edit
to smooth it out.Saves a lot of time over trying to clean up all the extra points that come from the scan of an object and running trace.

Dave Yanke
11-20-2008, 9:16 PM
Thank Mike & Frank, between the two of you I not only got a couple working templates, but Frank gave me that slap upside the head to get the light bulb to go off how.

The hour is late here so I think I will tackle this more in the AM.

Thanks guys.

Frank Corker
11-20-2008, 9:28 PM
I don't know where you are Dave but in the UK it's 02:40.

Richard Rumancik
11-20-2008, 11:09 PM
Dave, you asked for general suggestions so I won't give you a ready made pen template but ideas of how to construct a template. Same idea applies for any item.

I assume that you are using the scan in an attempt to make the pocket in a piece of acrylic to hold the pen for lasering. A scan is not that useful to generate accurate dimensional information for a holding fixture as there are too many sources of error. In addition you do not want to have so many points of contact that dimensional variations of the parts prevent some items from being inserted into the fixture at all. With pens you may not have a problem, but some items such as knives from Asia can be quite variable. In any event, I think trying to accurately trace the outline is the wrong approach.

First, when scanning, try to cover your item with a piece of white fabric to avoid shadows as much as possible. Take your scan and import into CorelDraw. Use it as a "background" image. Then you need to fix the orientation. The chances of having it aligned to the x-axis on the scanner are nil. To find out how much you need to rotate the bitmap draw a line from center of the top to center of tip and then use trig or whatever method you prefer to correct the bitmap orientation. (For lasered images you don't want to rotate bitmaps like this but this image is just for reference.)

I would get a pair of calipers and get some accurate dimensions from the sample. You need to decide which features to pick up on. For a cylindrical item like a pen I would probably pick up on a diameter on each end. There is no need to try to reverse-engineer the exact contours of a shape. Just pick some important details that will permit the pen to seat in the fixture with a minimal amount of looseness (play.) In the area of the rubber grip, I would avoid that area entirely. Establish a centerline and work off that. Drag some guidelines and adjust them to reflect what you are measuring. Then connect the dots to create a pocket outline. Define the laserable area.

You need 1 or 2 features to keep the pen sliding left to right (x axis constraint). So maybe use the end of the pen and the shoulder at the back where the clip attaches. Add a small amount for tolerances. Find one diameter near the tip and one at the other end to constrain it in the y direction. If you are lucky, the pen will sit flat on the surface, but if it doesn't then you may have to add something to level it in the pocket you make (so it doesn't rock and the laser zone is level.) The objective is to use the minimum number of constraint features needed. I would have liked to pick up on the diameter of the body at the top, but the clip seems to be in the way. But it would have been preferred to what I showed in my sketch, as the top of the pen is not as reliable of a reference. There are lots of ways; some better, some worse. Come up with an approach and go with it.

Cut one image in acrylic or wood and tweak your design if needed. You probably have to compensate for kerf to get a nice fit (e.g. cut the shape about .002 smaller all around.)