Laser Cut Cobblestone Streets and Paving

[Malachi Constant]

Reality-in-Scale has added some laser-cut stone streets, cobblestones, etc to their offerings.  Haven't seen them in person, but the photos look good ... marked as 1/35 scale ... laser-cut in cardboard ... sample photo below.  Other enlarged views available on their web site ... click "Roads & Sidewalks" category:

http://www.realityinscale.com/

Cheers,
Dallas

[Malachi Constant]

Dallas

[Malachi Constant]

These items seem like perfect candidates for Dave to do in O scale, so y'all might want to send him a note or two in case he doesn't browse this thread.  If you look here:
http://www.finescalerr.com/smf/index.php?topic=1055.msg17378#msg17378

... you'll find the basics for custom work ... and seems possible based on the replies that Frederic and/or Russ might be willing to help with some artwork ... and there are others on the forum equally capable to do the drawings.  So ... get to work making drawings or finding someone who will! 

Cheers,
Dallas

[Gordon Ferguson]

Frederic,

think you will find all the info you need on this site , about halfway down this page are the details for the "European fan pattern"

http://www.pavingexpert.com/setts01.htm#efp

I have still been experimenting with paving/setts this is a carved plaster I produced last week with the thought of using it as a master for some resin casting. The joints have been deliberately cut deeper than they should be to allow me to fill later with mortar/bitumen/dust/weeds, etc as required. White plaster is a bit difficult to photograph but hopefully you can see that roadway is trying to show some hollows/bumps and subsidence to provide "age" . This is 1/24 scale.

[Frederic Testard]

Thanks for the link, Gordon.
Here is the result of a first evening of drawings. (A gif image extracted from the pdf file).



Comments welcome.

[Malachi Constant]

Frederic --

If you study the cobblestone photo that I posted in the earlier message, it looks like each stone is actually a slice of an arc.  This is most apparent if you concentrate on the stones nearest the center of each circle. 

It looks like your stones are square or nearly-square, and thus produces more mortar areas that seem a bit large.

Actually, looking closer at your drawing, it seems that the second row from the center in each fan-shape pattern has the stone shape that I'm trying to describe.  I think it would be more pleasing to repeat that outwards ... but please wait for additional input before taking my advice! 

Cheers,
Dallas

[Frederic Testard]

Hi Dallas (and the others). Forum has been quiet these past days...

Well, I made some modifications to the drawing.



Again, comments are welcome.

[DaKra]

Frederic pointed me out to this thread.  Cobblestones are a good news / bad news / good news situation for laser cutting.   The bad news is, a lot of surface area means a lot of machine time, and most laser operators charge by the minute.   But the good news is, textures like this are one area where the machine can produce very nice results.  The other good news is, the laser made part can be used as a master for simple plaster casting, then you can make many more pieces, very quickly and economically.   

A 3d effect can be added to nicely round out the edges of the cobbles, randomly raise and lower the heights by a fraction, etc.   However once 3d goes into the mix, the machine time might go up.  This gets complicated to explain, but its basically because 3d forfeits manual power adjustment.  To increase or decrease the amount of power fired at the material's surface, the simplest way is to decrease or increase speed.   It can also be done in the graphic, but 3d graphics can get complicated, tweaking them ends up adding a lot of set up time, which is costly.     

And speaking of 3d graphics, and since today is Labor Day, here are some 3d laser cut burgers and dogs.

[Malachi Constant]

Dang, man, those aren't even bite size!  Did you do the painting on these samples?  Real nice coloring and shading on these tiny little bits.

Cheers,
Dallas

[Frederic Testard]

Dave, do you mean that if the white area was slightly reduced and the space between the gray and white was replaced by a whiter shade of gray, the cutter would automatically know it must engrave less deeply? It shouldn't be too hard to modify the basic file to get an eps rendition of this. Now it might be a big eps file, about 2 megs. Is it a problem for the machine?

And congrats for your little meal. It's impressive (but wouldn't feed a scale copy of me, I'm afraid... ).

[DaKra]

Frederic, the way you described, it would only create a step in the paving stones.   In order to creat a curved or slope  you need to use a feather edge.   I hope the attached graphic explains it better.

Dallas, funny you mention painting, as there is almost no paint at all on these food models.  The bun bread is naked cardstock, it comes out of the laser the proper color.  It starts out a dough color, and the laser basically toasts it.  A little brown weathering chalk is all they need.   

The burgers are brown card, cheese is yellow paper.  Only the dogs are painted, but they are a separate layer of card, so its a simple job.  A few specks of yellow paint applied with a pin makes the mustard.   The hard part is finding the  pieces when they fall on the floor.     

[Frederic Testard]

Well, I suppose I can do the feather. I'll try one of these evenings.
Edit : I forgot to ask. What should be the width of the gentle slope in the last of the three sketches?

[DaKra]

Hi Frederic.  Width of slopes, things like that are artistic not technical, so its just something you have to sort of get a feel for by looking at 1/1 cobblestones.   To make a curve as opposed to a straight slope, your feathering has to transition light to dark, with the dark building up faster as it approaches the edge of the raised object.   But for something like cobblestones its not critical.  3d is a murky area. It would be difficult to learn without direct access to a machine, even most laser operators don't go there. 

Dave 

[NE Brownstone]

HI Dave,
What type of files do lasers use? 

Russ

[DaKra]

Hey Russ, laser engravers seem to be optimized for Corel, but I use Adobe Illustrator on mine.   I've also accidentally sent a print job from a word processing program to the laser and it engraved the page, no problem.    Rule of thumb, if it will print on a printer, it will engrave in the laser. 

Some CAD type files need specific software to open and read them, that's a problem if the laser operator doesn't have the same program on his computer.   I run into that problem a lot.  Had to turn down a bunch of jobs.

Dave