bitmap files and laser cutting

[rue_d_etropal]

found this document about preparing input for laser cutting.

https://www.art.udel.edu/content-sub-site/Documents/howtos/Preparing%20Files%20for%20the%20Laser%20Cutter.pdf

 

it seems to suggest that simple bitmap files can be used for laser cutting designs. Give that all that is needed is a line of dots set to correct colour, This makes sense, but is it that simple.Just seems to be a lot easir than having to use other software. Would this also work for silhouette cutting?

 

Alternatively is there software to convert to suitable format?

[eldavo]

It all depends on your laser cutter and more specifically the software used to drive it. The ones I have come across used vector graphics input even when doing a raster engrave operation.

 

Cheers

Dave

[nick_bastable]

It all depends on your laser cutter and more specifically the software used to drive it. The ones I have come across used vector graphics input even when doing a raster engrave operation.

 

Cheers

Dave

Vectric cut2d allows import and trace of bmp http://www.vectric.com/products/cut2d.html  tried it but better results  creating a CAD file

 

nick

[AdamsRadial]

The Makeblock XY Plotter I use had an application with it (Benbox) that would take a bitmap as an input. I found it was better for engraving a design onto a surface as opposed to cutting out. It worked well for putting a photograph onto a surface, for example. However, it was much slower than vector burning as the machine was moving to an X-Y position, turning on the laser for a brief period, performing a dwell according to the engraving setting, turning off the laser, then moving to the next point to be engraved. With sparse dots this wasn't too tedious, but with a dense section of an image it seemed to take forever.

 

One problem with accuracy is that whilst the pixels in the bitmap are square, the dots burned by the laser for each pixel are of course circular.

[rue_d_etropal]

I would not want to have to spend a lot on a package, which was not OK, and when all I want is to convert bitmap files.

It does not surprise me about the effect actually on laser cutter. I think bitmap now only records the non white dots. It used to record the white dots as well 20 years ago, but problems wiith spool/file size resulted in the white dots being dropped.

Given that there is so much free software out there, there must be someone who has written a simple conversion program. Given that the types of designs I would want to do, have mainly straight lines, i can't see there being any negative effect .I would prefer something which could be used for silhouette cutting(coach sides).

[AdamsRadial]

There is a utillity called potrace which can convert raster images to SVG but the results often require some manual adjustments.  However, it is a DOS-based program, not a Windows one so there is no GUI and you need to be at home with passing command-line arguments to get the best from it. 

[rue_d_etropal]

I wasn'tsure which file format was required, but if it is SVG, then a simple google search comes up with some links, including this online one

 

http://image.online-convert.com/convert-to-svg

 

Interesting loooking at some of the others on list. WhenI see what SVG files are, I think it used to be possible to do something similar with an old scanning piece of software I used to have, certainly old, but it was possible to convert photos into something clean, like a b/w sketch. I found it useful , but did not think it might be something similar. Would not surprise me given that laser cutting is based on a very basic instruction set. that was partly why I found it frustrating. It did not need to be that complex.

[Happy Hippo]

All the laser cutting companies I have used in the past have specified .dxf format for CAD drawings.

 

I believe this is so then can maximise the cutting capacity of their machine, because they have manipulative software that operates with .dxf files  and can place parts to be cut in the most economical way.

 

ie The last laser cut I got in 1.5mm stainless steel was placed into the scrap areas of another customers order by this very nifty bit of software.

 

 350 pieces were cut from what would otherwise have gone into the scrap bin.

[rue_d_etropal]

they might put it in scap bin, but it wont be scap, it will be recycled. i remember when I worked for one steel company over 20 years ago, there was a lot spent on profiling(?) software. I think that must be similar, as it enabled maximum amount to be got out of one piece of steel.

 

As I said I am more interested in silhouette cutting, and noticed it states the Silhouette can import picture files which it then converts. That sounds good enough for me. Unfortunately because silhouette cutting is more a craft activity, it does not have any equivalent to online 3D printing. Having said that an online laser cutting service was far too expensive for what I wanted - bricks.

[AdamsRadial]

Potrace is http://potrace.sourceforge.net/  here, and has several output formats. If the Silhouette will take either SVG or DXF then it should work for you. It's free, and has both Windows and Mac versions.

[rue_d_etropal]

that sounds ok. I am stillat planning stage, but did not want to have to spend a long time learning another design package before starting. It also means I could start some designs now. Ironny is that to create the drawings I might actually design the 3D version and use the drawing part to create 2D drawing. Unfortunately my software can not create the files for laser or silhouette cutting.

[monkeysarefun]

Forgive me if I've misunderstood your question, but I'm assuming you are after a programme to convert bitmaps to vector files? If so Inkscape (free)  has that functionality. I've done a quick demo here, halfway through  post number 56.

 

The silhouette thread in the Scenery Structures and transport forum has a tutorial on Inkscape, if you haven't seen it already. Inkscape saves the file into a number of formats including .svg. I personally save them as .pdf which the cutter software supports..

 

Apologies if I've misunderstood what you were after.

[rue_d_etropal]

I had a look at Inkscape last year, and did not notice converter. I was only working out if it was worth doing some brickwortk then,but the cost of laser cutting online as too high.

I am now just investigating how easy it would be to design , say coach sides for silhouette cutting. I would still need to find someoneto do the cutting. Just an idea at the moment.