RE: Need a reason to keep my Laser Cutter
 

Moreover, I think you need money and an income from it to justify keeping this.

Best of luck to you, and I hope it pays off well.

RE: Need a reason to keep my Laser Cutter
 

OK for those that don't understand the difference between a bit map and a vector drawing.

WARNING: this will be very basic so if you already know about all of this just skip this entire post.

Suppose that a farmer asks you to take an aerial photo of his farm. His farm has an irregular shape sort of like the state of Nevada (no offense to Nevada). So you rent a plane and pilot, climb up a couple of thousand feet and take some photos. After you land you print the pictures out on your printer and with a highlighter you mark about where his farm is.

Although the pictures may be great quality it's difficult to say EXACTLY how far it is from the farmers house to the Eastern edge of his property or EXACTLY how many acres his farm includes. You may be able to estimate pretty close but you will never be exact.

Suppose that the farmer is interested in finding out EXACTLY how far it is from his house to the Eastern boundary or to that fishing pond on the north side of his property.

Well the answer is to hire a surveyor. The Surveyor will start from a known point on the earth and measure the EXACT distance and direction to the next significant point that makes up the farmers land. In other words he will measure the exact x coordinate and exact y coordinate to the next point and then on to the next point until he ends up back where he started. He will list all of these points in a list or database for later processing.

Back at the office the surveyor takes his list of points and plots them on a drawing to an exact scale, for example 1 inch on the paper equals 100 ft on the ground, then when he connects the dots he will have an EXACT scale drawing of the land. From there it is easy to measure any distance the farmer desires.

The first example is a bit map image. It's a picture of an object and it may or may not represent the true scale of the original. This is similar to a jpeg, bmp, tiff or a scanned plan of a model plane airplane.

The second example with the surveyor is a vector drawing and is an exact to scale copy of the original. In fact if you can imagine the surveyor back at the office connecting the dots that make up the drawing, the laser will do exactly the same thing with your vector drawing, connect the dots. Consider if the surveyor wants to make a larger or smaller drawing. He starts at the known point and makes another point in the exact direction or azimuth from the original but he changes all of the distances between all of the points an equal fractional or decimal amount. He'll soon end up with a smaller or larger scale drawing.

When you draw in a CAD program the software interprets your drawing as a series of coordinates, maybe just 4 for a simple box or maybe hundreds for a complex shape, but the important thing to remember is the software is building a database of all of the significant points that make up your drawing. When the computer sends this information to the laser it is really sending a series of x,y coordinates and the laser head just moves from one to the other to connect the dots just like the surveyor did to make his drawing.

The beauty of all of this is if you want to make the drawing larger or smaller. You just select the drawing and increase or decrease the size to whatever you want. The computer adjusts all of the distances between points an equal amount and the azimuth or direction remains the same. All this is done in the background but the result is a perfect copy that is what ever size that you want.

One other advantage to vector based drawings. Imagine the photo you took of the farmers land, remember you outlined his land with a highlighter? Well suppose he wants a larger picture, so you stick your photo in a copy machine and increase the size. What happens to the highlighter markings? They get bigger or wider, right? With a vector this does't happen because the computer just connects the dots as before no matter how far apart they are.

So to take a plan and digitize it, you will need to first scan it to a jpeg file and then import it into a CAD based program. Limeybob provided an example of a jpeg or bmp file imported into Delta Cad above, then you trace all of the parts you need. Finally you get rid of the jpeg scanned plan and what will remain is a digitized copy of the original.

RE: Need a reason to keep my Laser Cutter
 

Here is my first drawing, traced over a copy of the magazine plan from long ago. I have included the original in pdf format and my Delta Cad plan digitized then saved in pdf format that I printed at Kinkos. I have cut all the parts and am building the plane as we speak.

WARNING: Do not try to import or load a pdf file into Delta Cad! I somehow managed to do it and it seemed to work fine, I traced over the plan for about an hour and saved my work. Later when I tried to open the file it wouldn't open and crashed Delta Cad. I lost my work! Drats and double drats! Only load or import jpeg or bmp files for tracing. If you come across a pdf you want to trace you will have to convert it first.

RE: Need a reason to keep my Laser Cutter
 

on your last post you have the before and aft. of the plans. second one is digitized, which parts are you able to cut with your lazer?
i assume you have to copy lets say the former to another page to cut it or can you tell the machine which to cut based on color?
thanks

RE: Need a reason to keep my Laser Cutter
 

Welcome haikt.

Yes you are correct you move or copy the parts you want to cut to another page except with a CAD program you can use layers instead of pages. What is a layer you might ask? It is nothing more than a transparent page that sits on top or under your drawing which you can turn on and off at will.

Imagine the example of the farmers land above. If the surveyor wanted to show a pipeline that went through the farmers field what he would do is take his drawing of the field and use that as his base. Then he would lay a clear piece of mylar over the drawing and draw the pipeline on the mylar to scale right over the drawing of the farmers land underneath. He would attach this piece of mylar to the original drawing with a piece of tape along one edge so he could flip it up out of the way or down to see the pipeline. At all times he would always still see the original drawing of the land underneath.

This could be done with any number of mylar sheets. One showing the pond on the North side of his land, one for any roads that crossed the land and another for any electric utilities on the land. At anytime he could remove any piece of mylar to show only what he wanted to see and always see the original drawing on the bottom.

You do the same thing with layers in your CAD software. Just make a new layer and copy your pieces you want to cut onto the new layer. Your CAD software will allow you to make visible any number or combinations of layers that you wish.

When you trace your plan put the scanned jpeg on one layer and trace over it on another layer. When you are done or just want to check your work you can turn off or make invisible the layer with the scan and you will see only your tracing.

You could also move the pieces onto a different part of your drawing, way off to one side, out of the way. In fact this way may be faster. Move all pieces out of the way and group them by the type of wood that will be used for that piece. Then print or cut only that area of the top layer. I'm not sure which method is the industry standard but I use layers. A different layer for each type of wood to cut. Perhaps we can get a CAD expert to chime in on how this is commonly done in the real world.

RE: Need a reason to keep my Laser Cutter
 

I just use colors on one layer.
The laser cutter software driver cuts the colors in sequence.
In this case red for cut, green for write, and blue to detach the parts from the sheet of wood.
limeybob

RE: Need a reason to keep my Laser Cutter
 

Count me in on this. Just getting back into the hobby, will be going ARF sailplane to start out.
I enjoyed building, though and I've got a couple of those old plans laying around that would be fun to build.
Thanks,
Bill

RE: Need a reason to keep my Laser Cutter
 

I am design engineer but would not consider myself an expert.
We design large equipment in inventor (3d) then each Assy. and part is detailed on a drawing for the shop to make.
We do lots of sheet metal parts that are laser cut. For this we put a flat pattern on the drawing file that vendor uses. I think they take the flat pattern ( part that is unfolded) and use it in the laser.
I was curious how you determined which part to cut but layers make good sense

RE: Need a reason to keep my Laser Cutter
 

Count me in!

I designed this little glue caddy (its holds 2 sets of epoxy, 2-1oz bottles of CA, 1-2oz bottle of Ca, 1-bottle of Kicker, 2 ultra-fine sharpies and 2 X-acto knives). It just so happens to use a piece of 12"x16" ply for its construction and is all interlocking.

I had plans to offer then for sale for $25 shipped and paypal'd, but apparently that is to expensive...

http://img.photobucket.com/albums/v4.../GlueCaddy.jpg

RE: Need a reason to keep my Laser Cutter
 

Count me it. (Finally a thread that I am very interested in} I am building a 3D printer that will also have an option for laser cutting. Maybe we can trade some work. I like the barter system.

Mike M
Nashville, NC

RE: Need a reason to keep my Laser Cutter
 

would you be interested in trading carbon fiber sheet for cutting something out of carbon fiber sheets  like I send you 2 sheets to have one cut up
and I pay postage

RE: Need a reason to keep my Laser Cutter
 

049flyer,

I sent you a PM.

I already have files ready for laser cutting. Your table is 16" X 12", so I would "nest" differently for your cutting area.

I save my files as a DXF file. I create my vector line art in 2D CAD.

Interesting thing would be balsa costs? I'm guessing you buy wholesale?

I'm ready!

Charles

RE: Need a reason to keep my Laser Cutter
 

isn't gsview a linux program
full name is goast script view PDFs are goast script with embeded files and internet links
the last time I tried to install it there was a library conflict with KDE 4.0

RE: Need a reason to keep my Laser Cutter
 

GSview works on my XP workstation.
limeybob

RE: Need a reason to keep my Laser Cutter
 

Rob.rice what parts do you need cut and how thick

RE: Need a reason to keep my Laser Cutter
 

Welcome to everyone joining this thread. Most of us are just learning about how to import our ideas or plans into CAD software and then how best to format them for cutting by a laser cutter.

I want to tell everyone about the different modes the laser engraver or cutter is capable of. We all know the laser can cut wood and I'll talk about that in a minute but first I want to make sure everyone knows what raster means because it can have a HUGE affect on the time it takes to perform your laser cutting job. Plus as we all know "time is money" so you should always be on the lookout for ways to keep the laser time to a minimum as most laser cutters charge by the minute of run time.

In a previous post I told a fictional story about a farmer wanting an aerial photo of his land in order for me to explain the difference between a bit map and a vector drawing. If you don't know what I'm talking about just scroll up and read through the post.

So suppose that our farmer after realizing that he paid you $$$ for an aerial photo only to find that the photo would NOT accurately depict his farm to scale, decides to put the photo to good use. He calls you and asks if you can have that photo engraved onto a solid walnut wood plaque to be placed over his fireplace. You call your local laser engraver guy and he says "no problem". So how does he do it?

When you send a photo or graphic to the laser printer it knows by the format of the data that this is NOT a vector cut but a raster cut or engraving. A raster engraving is simply a black and white or in this case a Walnut and Burnt Walnut representation of the photo. And because the laser can minutely adjust it's power it can obtain many shades of unburnt walnut, lightly burnt walnut, and very burnt walnut to make a very detailed picture. To do this the laser printer head goes into raster mode which means that instead of being directed to travel from one x,y coordinate to the next, it instead travels very fast from side to side burning as it goes and constantly adjusting the power automatically so that a very nice photo results. Your inkjet printer works in much the same way as it prints, the head moves from side to side and the paper advances in small increments as the head lays down the ink.

BUT here is where it gets interesting: While your printer may lay down a strip of ink 1/16 inches wide with each pass, the laser beam is only .005 inches wide so to get the same detail as your printer it must pass over the piece 10 times to print or engrave the same 1/16 inch wide strip as the inkjet. Rastering is very SLOW and will cost you dearly if you are not careful.

OK you say but I'm doing vector drawing with my CAD software and I don't have to worry about this raster stuff. Maybe not, BUT if you include any text in your drawing like F-1, F2 or R1 and R2 to mark your ribs and formers and you use the wrong font, the laser will automatically raster all of your text first before starting the cutting portion of the job. All windows true type fonts will be rastered by the laser engraver/cutter.

So for now you should avoid sending text on the parts you wish to cut.

If you want to jump WAY ahead and find out about the correct fonts to use, let google be your friend and search for "single line fonts" and read up. Once loaded in your computer you can use them in your drawing, the laser will vector cut these fonts saving you $$$ in laser time.

RE: Need a reason to keep my Laser Cutter
 

Count me in as well.

Idownloaded Draftsight when I saw Planeman's Draftsight and Photoshop thread on the RCGroups Old timer plans prior to 1960 thread but Draftsight would just lock up my computer every time. Ithen purchased Turbocad 16 Deluxe as I wanted to convert a DWG file to PDF which Turbocad will do. Unfortunately it would not do it with the file that Ipurchased. Idid eventually get it.

Like you, Iam just a hobbyist and can not say I have any experience at all with cad programs even though Ihave Turbocad. It is something that I want to learn but never knew where to start. How do you import a jpg file in Autocad or Turbocad or other cad programs and then use it as a layer to trace and get the correct dimensions?

I am very interested in this thread.

RE: Need a reason to keep my Laser Cutter
 

the "TXT" font in DeltaCad should work for writing.
Need to test it to be sure.
limeybob

RE: Need a reason to keep my Laser Cutter
 

In Autocad it is"Insert", "Raster Image Reference"
It can go on any layer.
Once visible, you just start drawing over the top of the image.
It will probably be a black image, I use red to draw over the image, so it is visible
limeybob

RE: Need a reason to keep my Laser Cutter
 

OK so here is the skinny on how to get the laser to cut.

First the parts to be cut MUST be depicted by a line width of .005 or less. In Delta Cad select thin for your line width. If you are re-drawing an entire plan you can use whatever line width you want just make sure that the parts to be cut are the correct width on your "cut" layer.

Second the line MUST be the correct color. I have set RED as the cut color on my laser but other laser cutters may have their machine set for just about any color. IMPORTANT! The shade of red is crucial! In Delta Cad when you select a color you will see a color chart. The top most row of colors are the basic colors of red, green, blue etc. Below those are different shades. You should only use this top row of colors to activate the different features of my laser cutter and the very first color happens to be the red that you need to use to activate the vector cut function.

RECAP: To send a vector cut command to the laser use a red hairline or thin line to depict the parts you want to cut.

Final note: If you are NOT using Delta Cad don't worry. Most CAD programs allow you to see what the formula is for each color by giving a number between 0 and 255 to denote the amount of each of Red, Green and Blue are in each intermediate color. For instance the formula for Orange is Red=255, Green =102 and Blue=0. Find the formuala for RED and make sure it is Red=255, Green=0 and Blue=0.

Simple as that!

RE: Need a reason to keep my Laser Cutter
 

To import a jpeg into Delta Cad- Select File then select Import Image File from the drop down. You will then be returned to the work area and a large box will be depicted. This box represnts your image. Move it wherever you want and hit enter. It will be placed in the position of the box.

RE: Need a reason to keep my Laser Cutter
 

At what price did you bought this laser machine?

RE: Need a reason to keep my Laser Cutter
 

049,
Interesting choice for a cutter. Several tears ago I was considering a laser cutter and the one that stood head and shoulders above the others (in my opinion) the company that produced yours.
Being a relative novice at using cad this is a very good thread to follow, thanks for posting!

RE: Need a reason to keep my Laser Cutter
 

Interesting subject. I don't need anything cut, but like to learn more.

RE: Need a reason to keep my Laser Cutter
 

So now everyone knows how to activate the vector cutting function on my laser engraver/cutter. There are a few more colors you can use to perform other functions. I have set up the machine to use blue as the color for marking or labeling. Remember that marking will involve rastering and slow down the cut unless you are using single line fonts.

Black is the default color for engraving and not used for our purposes.

Green lines are set to be ignored by the machine. Why would I want green to be ignored? I use green lines to outline the sheet of wood from which I will be cutting the parts. So if I will be cutting parts from a sheet of balsa that is 3 inches by 16 inches, I draw a box with green lines of that size and then place my parts within the box.

Which leads to parts placement. Parts should be placed on the sheet with no part closer than about 1/8 inch from any edge. You may nest parts one inside another but you should leave a margin of at least 1/16 between the nested parts. It is important especially with nested parts that there are gaps in your cut lines where the laser will not cut so that the parts remain attached to the sheet. Consider the grain when deciding where to place these gaps. The width of the gaps is not terribly important, I use about 1/16 of an inch per gap and find that 2 to 4 gaps per piece is sufficient depending on it's size and shape. Don't forget to consider the grain as you place your parts.

By this time you should be ready to cut wood.