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Richard Rumancik
01-16-2007, 12:25 PM
After reading some of the successes members have been having with inlay, I am trying some experiments. I have specifically been doing tests on inlay text. My problem is in generating the offset curve for the inlay text. I want to cut about .003 oversize from the text curve.

Previously I attempted to use the contour tool. The problem I had (and has been noted on the forum) is that this tool generates hundreds of nodes on the offset curves, especially in areas of tight curves. The slider tool does not help (it reduces nodes but distorts the curve.) Manually deleting nodes is impossible and also can distort.

I few users got me trying the “Outline to Object” procedure as follows: Outline the shape (text converted to curves) in a line double the required offset. (Use .006 line for.003 offset). Then convert outline to object.

I have not had complete success. When I convert, the shape is usually filled oddly indicative of improper closure of shapes. I change fill to “no fill”, convert outline width to .00001”. Then it at least looks okay on the screen. Since the inside line and outside line are one curve, I need to break apart to isolate the outside line only. When I do this, I see that there are many breaks in the outside offset curve that I want to isolate. It may consist of several segments. (Applies to inside curve as well but that is discarded.) To select these parts, re-combine, and node edit (combine two nodes to one) is time consuming and prone to error.

Does CorelDraw X3 do a better job of the Outline to Object conversion? I am using V11. Any improvements in the contour function in Corel X3? Any other ideas?

Gary Hair
01-16-2007, 1:40 PM
Richard,
I have done a few inlays and I don't use offset at all. I draw the object(s) and vector away. The kerf from the laser is only .005 so you can hardly tell it's there. Give it a shot with just a hairline and see how you like it.

Gary

Mark Winlund
01-16-2007, 2:01 PM
Hi... with a reasonably fast computer, the fact that the offset is composed of line segments should not make much difference. I had V11 when my laser was new, now use X3, cannot see any difference. Because of what the contouring function does, it would be difficult to write software that would generate bezier curves exactly offset from another curve.

Regarding not using offsets at all.... with large parts, the kerf width might not be noticeable. Text is another story! Remember, inlay is something you get a big premium for.... worth spending some extra time on.

Quote:

"I have not had complete success. When I convert, the shape is usually filled oddly indicative of improper closure of shapes. I change fill to “no fill”, convert outline width to .00001”. Then it at least looks okay on the screen. Since the inside line and outside line are one curve, I need to break apart to isolate the outside line only. When I do this, I see that there are many breaks in the outside offset curve that I want to isolate. It may consist of several segments. (Applies to inside curve as well but that is discarded.) To select these parts, re-combine, and node edit (combine two nodes to one) is time consuming and prone to error. "

Regarding the above, I have not had much success using outline widtdths less that .002. Corel seems to lose track of where the ends are. Flexisign pro has a function that will join "loose ends" and does an excellent job of repairing curves.


Regards, Mark

Mike Mackenzie
01-16-2007, 2:49 PM
What we have done when handling text or small objects is to mirror the image and fill the text with white draw a box around the text and fill it black. use at least 1/8 wood and then raster away the background leaving the letters raised to a certain height.

Now raster the pocket to the desired depth into the inlay piece then glue and mate the two parts clamp overnight then sand the back away it gives you remarkable fits. The nice thing about it is you handle everything on one pc. It would be easier to do it in separate lines rather than one large paragraph due to the amount of material you are removing.

This process takes a little longer but I have found that the fit is beautiful.

George M. Perzel
01-16-2007, 3:13 PM
Hi Richard;
I can't imagine why you need the level of precision you are trying to achieve, but am sure you have your reasons. Most of the time I do exactly what Gary does with great results and I've inlaid ivory, ebony, plastics, shells, etc, etc in many different wood.
Try Mike's technique-it works great and poses a headscratching response from folks who ask " How did you cut and fit all those little pieces"?. Here's an example:
Best regards;
George
LaserArts

Rodne Gold
01-16-2007, 5:40 PM
X3 will solve your problems , firstly the smart fill tool and create boundary tool will be immensely helpful in generating "offsets" and the countour tool has been fixed and it doesnt generate a zillion points. Offsets cannot be generated mathematically for every shape , so corel often messes up in this regard as it does the best possible job which is not always the best for your application , X3 has improved on other versions in this regard too.
There are tons of other features that will make life easier too - upgrade , you wont be sorry.
(You will need to have a decent puter and XP with service pack 2 to use X3)

Dave Fifield
01-16-2007, 6:05 PM
Agreed with Rodne et al. An upgrade to X3 is required. The Contour function is muchly improved. In X3:

1. Select the object (make sure it has a fully closed boundary or Contour won't work)
2. Contour it with 1 line, 0.004" (or whatever) on the outside, make sure the line color is black and the fill color is white
3. Hit CTRL K to break the contoured object apart
4. Go to the Object Manager (docker) - you will see two items highlighted - click on just the top one of the two (that's always the inner line that you don't want), then hit the DELETE key to get rid of it.
5. Print to laser and away you go

If you need to do INSIDE curve contouring (such as the center of the letters A,B,D,O,P,Q, and R), you use almost the same procedure, but in step 2, contour the line 0.004" on the inside, and in step 4. make sure to delete the outside object.

Hope this helps.

Rodne Gold
01-16-2007, 6:21 PM
One thing to be aware of when doing inlays and in fact all engraving/cutting where one object fits on or into another is to keep the orientation of the parts the same. Most lasers are NOT exactly calibrated in the X and y direction the same , so rotating a part sideways will often lead to a poor fit if the other part wasnt rotated.
If you do have a calibration function in your driver , use it.

Chris Cordina
01-16-2007, 9:21 PM
I have found on inlay lettering I raster at one size then increase font size a couple of pts and then vector the letters. Depending on font style just 2 or three pts are plenty.

Richard Rumancik
01-17-2007, 6:53 PM
Thank you to all who responded.

Mike/George: you have an interesting approach. Obviously a lot of rastering but might be useful when there are a lot of parts to the inlay.

Rodne/Dave: Thanks for comments on X3. Looks like I need it.

Chris: I know this idea of increasing font size must have worked for you, but it did not look promising when I did an experiment with it. One point size increase results in about a .010 to .015" step depending on font. There does not seem to be a lot of control. I overlayed an "A" from Benguiat font of size 72, 73, and 74 and the outlines did not look like "contour" lines. Fonts have special mathematical algorithms to control how they grow. For some fonts it might work well enough.

Robin Lake
01-21-2007, 11:25 AM
Chris: I know this idea of increasing font size must have worked for you, but it did not look promising when I did an experiment with it. One point size increase results in about a .010 to .015" step depending on font. There does not seem to be a lot of control. I overlayed an "A" from Benguiat font of size 72, 73, and 74 and the outlines did not look like "contour" lines. Fonts have special mathematical algorithms to control how they grow. For some fonts it might work well enough.
Commercial fonts contain what is called "hinting." Kerning is also built in to commercial fonts, to varying degrees. Kerning is important to the look of the word or line of words, but not to the fit of the letter.

Here is an excerpt from a site located by a search for "font hinting."

Quote:
Hinting provides information to the raster image processor (RIP) for rasterisation of fonts. Low resolutions or small font sizes may otherwise present the glyph (shape of character) with various distortions:
Stem widths are unequal
Line thicknesses are unequal
Location of features are inaccurateThe method of hinting depends on the font type. TrueType and PostScript fonts use different methods. For Type1 fonts (PostScript fonts) only hints for vertical and horizontal stems are defined. For TrueTrype a 'hinting language' allows for very detailed control of the raster process. Modern type creation tools (Fontographer, FontLab) support both types of hinting in an intuitive way.
Close Quote.

Commercial fonts probably always contain hinting. The vast preponderance of freely available fonts possibly never. That makes free fonts a better candidate for Chris' method.

Robin

Dave Jones
01-21-2007, 11:41 AM
Hinting doesn't really help. It's for rasterizing fonts, but the fonts remain as vectors in this application.

The problem with this method is that a typical character is not square, it is rectangular. For example, say you increase a font from 10pt to 12pt. You increase the width and height 20%. But since the character might be twice as high as it is wide it now has a vector around the original one that has twice the space vertically on horizontal surfaces as it does horizontally on vertical surfaces. Using the interactive contour tool gives a uniform space from both vertical and horizontal surfaces.

If your laser dot is an oval instead of a round dot, then this might actually work out OK. But if it is a round dot then you want an even amount of space on all sides to compensate for the beam diameter.