January 10th, 2009 by admin

A CNC Foam cutter is a machine that cuts blocks of foam into a variety of different shapes and sizes through the use of a computer that fully automates the process. This sometimes is referred to as a hot wire foam cutter because a hot wire is used to make the cut in a block of foam.

Usually the wire is made from stainless steel, nichrome and the wire can be very thick. The wire is heated using a process called electrical resistance which means it gets hot enough (around 200 degrees centigrade) to vaporize the foam before the wire makes contact with it. This process creates a smoother cut and produces a variety of shapes and sizes.

Depending on the length of the wire, the process will cut a shallow or deep cut. The wires have to be held in the machine under a very tight tension to keep the wire from sagging when making the cut. On many CNC foam cutting machines this wire is held vertically so that it doesn’t create the problem with sagging.

These shapes are cut by the cutting wire that is attached to the machine. They will cut either polystyrene or polyurethane blocks. The types of foam that a CNC foam cutter can cut include anything that is thermofusible and expanded. What this basically means is that the foam has to be able to melt at one of the lower temperatures. Some of them include:

- Polystyrene — these are blocks of balls that are expanded.
- Polystyrene — this is extruded foam and comes in a variety of colors that include green, pink, purple or gray and these are usually plates that are smooth.
- Polymethacrylimide — a very expensive material and it is rigid foam with a low density.
- Polypropylene — which is flexible and expanded and can be a solution to protection from shock.
- Polyethylene — these are foams that are tear resistant and flexible.

With the CNC Foam cutter you can form a more prism like or tapered shape in the block of foam. A hot-wire that is under a high tension to cut the foam. There are stepper motors that provide the precision and accuracy for the work and there are components called races that control the stiffness of tension of the wire.

Some CNC foam cutters also offer different attachments like a lathe and this allows the machine to use either preformed or stretched wire. Also the machine is able to cut a variety of shapes including spirals or blocks of ornamental structure like balusters for stairways or planters.

There are a variety of uses for foam cutters that include making signage, model airplanes, protyping, lost foam cutting and more. The CNC Foam cutter is a flexible machine and is only limited by the imagination.

Although many people prefer to purchase a CNC foam cutter there are also plans on the Internet that show how to make them inexpensively for hobbyists and others who are interested in working with foam.

CNC Information is a new Community website all about CNC Foam Cutter. Stop by today to get your free ebook just for signing up to be a member of our free site. Get all of the information you need on CNC Foam and a free CNC Ebook on the basics of CNC. Stop by CNCInformation today.

Article Source: http://EzineArticles.com/?expert=Ivan_Irons

January 9th, 2009 by admin

How to Get Started with CNC Machines

from wikiHow – The How to Manual That You Can Edit

When new to CNC machining, it may seem very complicated; however, putting an order to how you get started will prove helpful.

Steps

1. Get a CNC machine. Choose car fully make sure the machine is rigid enough to cut your material and that the machine also has enough travel in X, Y and Z to fit your workpiece plus the cutters or tooling height, Don’t forget that you can clamp parts down, then slide them over and clamp down again to cut long parts.
2. Purchase machine tooling. Make sure that you get a couple of cutters; some will probably break if you are not careful. When choosing tooling make sure to get a wide array of tools, you can save a lot of time if you use the correct tools. Bull nose, Ball end, V-Bit, Flat End Mills and Convex cutters may be a good start. Also, make sure to get an assortment of sizes as you cut things. Use the larger tools to “rough out” areas then do the fine details with smaller tools. This will not only speed the process but your tools will last much longer as well.
3. Do find a good CadCam system programming with gcode or conversational programming will work, but is certainly not the most effective or easy way to start.
4. Make sure to learn your machines control very well. Learn how to setup the tooling offsets ,work offsets and learn at least the very basics of gcode programming before you start using your machine.
5. At this point you should start to tackle your CadCam system start simple! first cut a basic rectangle then a rectangle with rounded corners to make sure the code output and settings are OK.
6. Be patient there is a lot to learn. Keep your mind open there are always new and faster ways coming about to get your parts cut faster don’t be afraid to experiment or check with others for advice.

Tips

• ALWAYS! Cut a “dry run” to make sure your program is good.
• Find the correct feeds and speeds for your tooling. They can dull quickly or break if you run them too fast or too slow.

Warnings

• Wear safety glasses. Tooling can sometimes shatter or explode!
• If you are using a large machine, the safety mats and warnings are there for a reason!

Related wikiHows

• How to Learn Welding As a Hobby
• How to Construct a Bar out of Beverage Cans
• How to Make a Wreath With Clothes Hangers
• How to Build a Cutting Laser

Sources and Citations

• http://www.cnc411.com

Article provided by wikiHow, a wiki how-to manual. Please edit this article and find author credits at the original wikiHow article on How to Get Started with CNC Machines. All content on wikiHow can be shared under a Creative Commons license.

January 8th, 2009 by admin

Every CNC machine must contain a controller. The controller is a physical array of circuitry that allows the computer to talk to the machine. The computer takes the CAD files, comverts that into a pile of code, g-code, with the help of CNC software. It then sends it out through a cable to the controller. Once the information reaches the controller, the controller takes it as signal pulses and sends it to the correct stepper, or servo motor making it move. Every single movement has its own piece of code which can make the code quite length in the end. Thought there are many suppliers of cnc controllers, there are also many people that take on the task of building their own controller. It takes quite a bit of skill to build one of these the right way but building your own keeps the cost down significantly. Another plus is that you can add ass many axis as you want/need where as if you bought the controller, you may have to spend another 200 + dollars to add another axis.

January 6th, 2009 by admin

Now that you have looked at your options, you can begin drawing up a design. You need some type of plans to follow while building the machine. This way, you have your thoughts written down to look back on. It also provides you with a visual of the machine and a way to see whether everything is going to work properly and not run into other parts. Many plans are already made and have been posted all over the web to make this step alot easier. Some plans focus on using the cheapest available parts to keep the price down while others use the most reliable parts to achieve great accuracy. Many plans involve both and show how to build a machine that is reliable enough for the do it yourselfer while keeping the price low. Engadget has a build your own cnc machine post and decided to build thier machine out of scavanged, recycled, and adapted parts here How-To:Build your own CNC machine. Solsylva offers DIY plans for more accurate well built machines but will cost you alittle to get them.