Cleaning and Cutting Vectors

[DavidJHolmes]

When cleaning up vectors for cutting, is more nodes/anchor points good, or bad? When I draw images in Illustrator I tend to use only the number anchor points necessary to achieve a curve etc... However some vectors, especially ones that have been automatically converted from Raster images have loads. Some I tend to delete that disturb the smoothness of the lines, but generally leave them as when I cut on the Vinyl Cutter the lines are generally fine.

Does the same apply to Laser Cutting? Should I be using more or less anchors, and does it make a difference to smoothness of the cut?

If I can draw a curve utilising 2 anchor points only, I don't see why 4 would be better. More than anything I think it would disrupt the smoothness.

[Spooky]

Curves with one radius only require 2 anchors and a rad point, multiple curve rads require more anchor points

Less is better and avoid splines like the plague

best wishes

Dave

[DavidJHolmes]

Ah, ok I think I'm getting confused with splines. When I draw a curve in Illustrator I use the pen tool and have two points. Its not till I expand the drawing I get the points. I can use the program but don't know any of the technical terms, which makes it hard to ask for help

On a side note, what is the cutting width of the laser? If I create two shapes with 5mm slots to join two pieces so they interlock, will it be too tight, too loose, or perfect?

Thanks

[PhillyDee]

Cut a 50mm square, (Or whatever) measure the inside and outside. Divide by 2. Thats your size. Mine is around .004" (0.1mm)

[Spooky]

Phil's got it David,test cutting a square is about the only real way to find out, even on two machines the same it's not possible to give an exact figure, it depends on a lot of things, focal height, length of focus from lens, tube power, age of machine (tube) etc etc..

a good start point is indeed 0.1mm kerf width but that can vary quite a bit material also makes a difference, the kerf width in abs is different to acrylic, mdf is different to plywood..etc etc thickness of material also affects it..



best wishes

Dave

[Spooky]

oops...


Pen tool drawing a curve is a spline, those extra points are theoretical x/y positions that generate an average between them hence the curve. Great for drawing pictures but rubbish for laser and cnc machines.

Different software reads the spline points differently and will generate a different curve, even save formats between different packages will affect it hence the reason I avoid splines at all costs

best wishes

Dave

[DavidJHolmes]

Ah cool! I need to wait till I get my laser then to work that out!

I really need to learn AutoCAD but the learning curve seems awfully steep!

[Spooky]

It is and it isn't David, It was for me as I had to provide architectural drawings of buildings and such like but for the limited requirements of laser cutting it really isn't too bad,

The later versions have a huge number of things you will never use such as dynamic blocks, block references and indeed blocks in general as well as a load of other stuff like hatch patterns (and how to write them) that are way beyond normal laser cutter use.

Tools wise from the autocad toolbar you will use very few possibly limited to the following:

Line (Draws a line between two points)

Construction Line (Draws a line of infinite length )(used for lining things up across your drawing)

PolyLine (Draws a line between multiple points but as a single entity)

Circle (Draws a circle with a given radius or diameter)

Curve (Draws a curve between two points with a specified radius)

Chamfer (Adds a corner chamfer between two joined lines)

Radius/ Fillet (Draws a corner radius between two lines)

That will get you a basic drawing and the other tools will make it easier to modify,

Trim

Extend

Array

Copy

Scale

Mirror

Offset

Join

Are next inline for picking up and making things easier but past that most of the others are things you will never use.

Hovering the cursor over any given button will get you a description and example of what the button does.

When I run training seminars for AutoCAD the laser/cnc one takes one day, the basic architectural one takes 2 weeks minimum to give you some idea of the involvement of it.

Any version of AutoCAD after 2000 is fine and will make your work a LOT easier once you get used to it, 80% of my time drawing wise is used up fixing client drawings done with other packages such as Corel Draw or TurboCAD to make them use-able for laser cutting.

As my late father said to me many years ago when referring to both software and engineering in general "Cheap,Fast,Accurate, Pick any two son"

best wishes

Dave

[PhillyDee]

Wise words! I mainly use lines, offsets, trim and fillet/chamfer. Rotate when required (Sometimes direct coordinate entries, but not often!)

Easiest way to start is to just stick a line down. You can use infinite construction lines to start, before deciding how long to make it. A line on the X (Horizontal) and a line on the Y (Vertical). Use offset to offset the lines 50mm. Then use trim, select all the lines, and press enter. You then just click on the lines you do not want or need. It will trim them to a perfect corner. Enter is used a lot, mainly after selecting your entities (technical term meaning lines or things :p), and you can also type the name of thing you want directly into the white box at the bottom.

Read the bottom during and after you use the function. It gives you options that you can use by typing the appropriate letter when it prompts you.

I am using draftsite (or whatever it is called) at the moment. Works just the same as early autocad versions, and is easy enough to use. I am fortunate in that I done an engineering apprenticeship for 4 years and with that cam 4 years of college, I learned autocad / pro engineer, 3d modelling and design. Of course, Dave there does it for a job, I just play with big expensive machines .

The internet is a wealth of information, and you can always ask in here. Someone will give you an answer soon enough!

[Spooky]

Phils bang on there

Great start is using construction lines, I use them a lot for cleaning up scans and such like..

Also a box from right to left (green) will highlight everything it crosses and box from left to right (blue) will highlight everything it contains.

best wishes

Dave