Adding Tabs in Corel X3

[Joe Peacock]

Would anyone be able to tell me the best way to add "tabs" to some small parts so they don't fall through the screen when I pick up the parts? I am making templates and I want the pieces that will be discarded to stay with the template when I pick it up and then I will push them out when I get the parts up and away from the laser. I need really small tabs like .005 or something like that so that they aren't really noticeable on the inside part of the template.
Thanks,
Joe

[Scott Balboa]

Hmm I'll have to think about that one...

Are they falling through when engraving or only when trying to pick up the whole sheet/template? On small parts I usually turn off the laser after engraving and use double-sided tape to "pluck" small parts out of the sheet, one at a time. If you have a zillion of them and this is too involved, then maybe you can rig up a tape-sponge (of sorts) with double sided tape stuck to the face, and the other side peeled with adhesive exposed, and use that to push into the sheet and pluck out the small parts?

[Richard Rumancik]

Joe, a couple ideas.

First, save a copy of the images of your un-altered shapes in case you need to revert back for some reason.

If it is a geometric shape like a rectangle you need it convert it to curves first. If the shape is closed, then open it at one of its nodes. (Right click on a node and then break apart). Set line width to say .00001" so you can see things better.

Then use your eraser tool. Set the eraser style to round, and the width to say .007". Move across the line with the eraser where you want a tab. It will cut across and make a .007" gap in the curve.

The curve must be open, not closed, or it will try to "heal" where you attempt to erase. Like a ball hitting an elastic wall.

When cutting rectangular or other rectilinear shapes, I usually put the tabs at a corner. In this case I would just break the nodes apart at the corner. Then select the node from one segment and move it .007" using the arrow key.

Note: if you erase .005" from the line, and your beam diameter is .005", the tab might effectively disappear altogether. You need to account for beam diameter in your eraser size.

With thin wood you need to be careful with orientation, as a tab along the grain will be much weaker than across the grain.

You will have to experiment with tab widths to find what works for the material, laser settings, and lens. Don't go overboard - use the minimum number possible - or you will create new problems. You want to be able to get the parts out without damage or having it show.

[Joe Peacock]

Scott..........the parts are small and I want to be able to pick up the whole 3"x5" template with the cutouts in it and then remove the pieces away from the machine. This will make the mfg. process a whole lot quicker.

Richard....thanks for the very specific input on how to accomplish what I am trying to do! I will do some experimenting. Is a hairline thicker than .0001? How can I tell if I have moved the node .007" using the arrow keys?

Joe

[Richard Rumancik]

Joe, a hairline is .003" (which is about the diameter of a hair.) It seems to be the Corel default; I find it a bit annoying to use such a wide line width as it can hide detail and make it difficult to see what is really going on with underlying nodes etc. So I generally set my line width small which is more like the way a CAD system would work - part features really don't have ANY physical thickness. You don't have to use .00001" lines but I'm afraid it might partly hide your gaps if you use 003".

You can set the "nudge offset" to .007" or whatever you choose. (On my system the nudge offset parameter is at the top of the screen between UNITS (inches) and the "Duplicate distance" boxes.) After you set the nudge offset, you can select an object and jog it around the screen with the arrow keys. But you can also jog a single node around using the same method. If you haven't tried this in the past, experiment with a nudge of .10" so you can see the effect better.

Maybe try this: Draw a rectangle. Convert to curves. Break it apart at the two opposite corners. (select the rectangle to highlight 4 nodes, then right click on one corner -> break apart. Select opposite corner node -> break apart. Then ARRANGE ->break curve apart. Now you have two L's. Select one "L" of the shape with the pick tool, then click the shape tool and select an "end" node by dragging a window over the node. The node will highlight. Now if you then press the arrow keys, the node will jog around by the nudge distance previously set. You will want to nudge it in the direction that shortens the line length. This will create a gap equal to the nudge distance. If this is unclear let me know and I'll try to clarify.

This method is suitable for rectilinear parts which are oriented to the x and y axis.

If you prefer not to have the tab right on a corner, then I'd use the eraser method and eyeball the location of it. It is often less work than node editing. Usually there is no need to be too fussy about the exact tab location.

[Dan Hintz]

Joe,

If you don't care where the "tabs" end up, select a dashed line instead of a solid one. I cannot remember if Corel allow you such control, but if it does, try editing the length of each dash.

[Rodne Gold]

The easiest way is to draw a rectangle the width of the tab , place it on the vector line you want to break , select the "virtual segment delete" tool from the sidebar and click on the vector you wish to break thats enclosed by the rectangle (click it inside the rectangle)- hey presto - delete the rectangle and you got your tab.
Best of all , the "dashed" object is still treated as a whole.

[Joe Peacock]

Thank you to everyone who has helped me with this.
Joe

[Niklas Bjornestal]

Or else you can lower your ppi until the parts stays in place...

[Joe Peacock]

Or else you can lower your ppi until the parts stays in place...
Niklas,
Thanks for the suggestion but these are templates and the edges have to be as smooth as possible.
Joe

[Joe Peacock]

All of the methods suggested worked but I didn't think it all of the way through about the tabs. Since these are templates used in the craft industry the edges of the inside of the cut outs have to be as smooth as possible. I was able to get the tab down to .004" and they held the part in place OK. The problem came when I tried running a pencil around the inside of the template. Imagine a 1" heart. When you run a pencil around the perimeter of the heart even the little tiny part of the tab disrupts the line and it is easy to see that the result has a flaw in it. I will probably be making 1,000's of these with different geometries and I was looking for a way to keep all of the parts together so that I could place them in the packaging without having to hunt them up all over the laser cutting surface.
I think my next step will be to raise the sheet up off of the cutting surface about an inch and make individual "baskets" some how that all of the parts fall straight down in to. I am kind of thinking along the lines of something made from acrylic with multiple holes in the bottom of it for air flow.
The parts are cut from .062 acrylic and they are 3"x5" and I can get 8 of them on a 12x16 sheet so things are a little tight on the size of the baskets the parts will fall into.
I REALLY appreciate all of the help and if you have any more ideas I would appreciate them too.
If you want to see the kind of stuff we sell go to metalclaysupply .com. I am not trying to sell anything here, I was just thinking you might want to see what we are all about. Our customer base is 99.2% women and they expect to get what they pay for and we have been pretty successful in meeting their needs.
Thanks again,
Joe

[Rodne Gold]

The acrylic is thin which means you can put it directly on the table surface and cut without any meaningful melt damage etc.
Use anodised aluminium "shuttle" sheets , IE have 2 sheets of ally and just cut directly on em , removing the whole sheet and replacing it with a preloaded one. Anodised aluminium wont reflect the laser.

[Mike Null]

Joe

I checked out your web site. WOW! Nice looking site and very interesting. Lots of things folks here on SMC can use.

[Dan Hintz]

I was going to make the same suggestion as Rodney... several sheets, just swap them out wholesale as each one is finished, and you can spend time "weeding" while the next sheet is cutting.


Add your website to your name (go into the User Control Panel)... if Mike says there's interesting stuff there, I want to check it out, but you can't add it directly to your posts.

[Joe Peacock]

I was going to make the same suggestion as Rodney... several sheets, just swap them out wholesale as each one is finished, and you can spend time "weeding" while the next sheet is cutting.


Add your website to your name (go into the User Control Panel)... if Mike says there's interesting stuff there, I want to check it out, but you can't add it directly to your posts.
I am sorry if I broke the rules. I didn't know and I will do what you suggest.
Thanks,
Joe

[Joe Peacock]

The acrylic is thin which means you can put it directly on the table surface and cut without any meaningful melt damage etc.
Use anodised aluminium "shuttle" sheets , IE have 2 sheets of ally and just cut directly on em , removing the whole sheet and replacing it with a preloaded one. Anodised aluminium wont reflect the laser.

Does anyone know where I can purchase 12" x 16" anodized aluminum sheets. What thickness do you suggest?
Joe

[Dan Hintz]

Chewbarka is my first thought...

[Richard Rumancik]

Rodne - does it need to be black anodize or does clear work?

Joe - you might try to search on "aluminum sign blanks". The problem with using thin aluminum is that it might not lay flat on the table. I have never tried cutting direct on aluminum so can't comment on what to expect. But I'd tend to err on the side of being thicker to avoid warpage.


. . .I think my next step will be to raise the sheet up off of the cutting surface about an inch and make individual "baskets" some how that all of the parts fall straight down in to. I am kind of thinking along the lines of something made from acrylic with multiple holes in the bottom of it for air flow.
The parts are cut from .062 acrylic and they are 3"x5" and I can get 8 of them on a 12x16 sheet so things are a little tight on the size of the baskets the parts will fall into.

This might work - if you are doing production runs some tooling may be practicable. Do you need individual baskets? Could you maybe have a raised table with openings for the parts, with a "drawer" or tray you can pull out from the front of your laser - through the door? Keep in mind the parts need to fall well away from the beam, or the laser may mark them up when making subsequent parts. An inch clearance is not enough. They need to fall flat and out of the way. Also you have to control your power level carefully - if too much excess power it will mark up the dropouts.

[Lee DeRaud]

Scott..........the parts are small and I want to be able to pick up the whole 3"x5" template with the cutouts in it and then remove the pieces away from the machine. This will make the mfg. process a whole lot quicker.Ah, finally got it: you're going to throw away the small (tabbed) bits, but don't want to have to pick them out of the machine one at a time by hand.

Can't you just keep a small shop-vac next to the laser to clean up after each batch?

[Rodne Gold]

We use black , any sign supply co should stock it in sheet form and be able to guillotine cut , we use 1.5mm stock. It gets sort of sticky after a while which is good

[George D Gabert]

Just rambling

Could you use standard 1/8" ply with your pattern cut out just a little oversized. Place that on another ply sheet with you pattern cut out just a little undersized, for the vacuum to pull the parts into the top pattern. Place the sheet to be cut on top.
Cut the parts. Remove tooling from laser. Place packaging on top and turn over. Now everything is dropped back into place.

Regards
GDG