Tuesday, December 30, 2008

Cnc Cutting Machine

CNC Cutting Machine
The operators of the present-day CNC cutting machine demonstrate many of the same skills as those possessed by various traditional craftsmen. The operators of the CNC cutting machine include the men and women who design and make cabinets, woodwork, signs, and a whole range of metal, solid surface and plastic objects. The manufacturers who employ these operators know how important it is to have a good quality CNC cutting machine.

A good quality CNC cutting machine has a cutting table that covers the area bounded by a length of four feet and a width of eight feet. A quality table can handle satisfactorily a standard 4 x 8 plate of metal, wood, plastic, glass, or stone. A table that lacks a sufficient length or width will make it necessary for the operator to repeatedly reposition the plate. Operators of the CNC cutting machine refer to such repositioning as indexing.
A good basic CNC cutting machine does both plasma and oxyfuel cutting. Refinements on a basic cutting machine might provide it with the ability to perform other functions, functions such as:

CNC Cutting Machine
-spotting holes for drilling
-drilling aluminum
-cutting a shape in the sides or end of tubing
-routing wooden shapes.

Other modifications on a CNC cutting machine might be directed at installation of the equipment for laser or water jet cutting.

The selection of a CNC cutting machine will be primarily determined by the nature of cutting that will be performed by the machine operator. For some operations, it will be necessary to do only straight cutting. For other operations, the cutting machine must perform bevel cutting. Bevel cutting allows the operator to trim, reduce, shave, and pare the material in the plate.

Sunday, December 28, 2008

An Engineers Guide to Cnc Machining Cad/cam

CNC Software
Computer Numerical Control (CNC) of manufacturing machines such as lathes and mills was the next stage of development from Numerical Control (NC). NC control had allowed the machines to be run automatically using a fixed program for the first time. This increased automation of the manufacturing processes led to considerable improvements in the consistency and quality of components. The program was, however, long winded to create and difficult to alter.

The addition of a computer within the machine allowed the program to be viewed and edited making it easy for alterations to be made to what had previously been a fixed program. This allowed operators to write programs directly into the machine and update and optimise them as they went. This required a new breed of machine operators who had the skill and training required to program the machine from engineering drawings in addition to their traditional skills.

CNC Machining
The next stage of development was Computer Aided Manufacture (CAM), this allowed the program to be created offline from the machine, not by typing in dimensions from a paper drawing, but by taking the geometry directly from Computer Aid Design (CAD) files. A software package would be used to create the program from 2 Dimensional CAD data of the geometry and then add tool and speed/feed information. This program could then be post processed into a language appropriate to the machine being used. This development further increased the required computer skills of the machinists but made programming of complex shapes just as simple as creating simple shapes. It also reduced the chances of errors within the program as more of the programming was automated.

The current state of the art is 3D CAD/CAM, which allows programs to be created directly from the 3D solid models created by the design engineers. This technology allows parts to be machined without any from of paper drawing, as all the tool paths are derived from the 3D model. The advantages of this process are most obvious when creating development or prototype parts as not only is the programming time considerably reduced but also programs can be simulated and verified offline. Therefore no time consuming line-by-line proving of the program is necessary at the machine. A further advantage to this system is that more complex three-dimensional forms can be easily programed allowing more flexibility to the designers, and where necessary making the creation of more stylish shapes, cost effective even for very low production.

All these developments have completely revolutionised workshop practices within a generation, as machinists have evolved from skilled operators running manual machines, to computer literate programers able to drive complex 3D CAD packages that had previously been the domain of the designers.

Saturday, December 20, 2008

CNC Milling Machine Buying Tips

CNC Milling Machine Buying Tips
CNC stand for Computer Numerical Control, and refers specifically to the computer control of machine tools. The main purpose of CNC Milling Machines is to repeatedly manufacture complex parts in metal as well as other materials, using a specially coded program. This specially coded program that is used by CNC Milling machines is written in a notation called G-code. G-codes represent specific CNC Milling functions in alphanumeric format. CNC Milling was developed in the late 1940's and early 1950's by the MIT Servomechanism Laboratory.

CNC Milling Machine
1. About CNC
Computer Numerical Control (CNC) Milling is the most common form of CNC - CNC mills can perform the functions of drilling and often turning - CNC Milling machines are classified according to the number of axes that they possess - Axes are labeled as x and y for horizontal movement, and z for vertical movement - The evolution of CNC milling machines drastically changed the manufacturing industry - Curves are as easy to cut as straight lines, complex 3-D structures are relatively easy to produce, and the number of machining steps that required human action is way down.

2. The Fabrication Process
With the use of CNC milling machine the fabrication process of the materials have been trimmed down to just a couple of steps. CNC Milling machines now days are driven directly from computer softwares crated by CAD software packages. With the use CNC Milling machines the assembly of parts can go from brief designs without any intermediate paper drawing works being required. In one sense, with the use of CNC milling machines industrials tasks are done must easier and much faster and the production cost of the company is also lessening out. CNC machines may be said to represent special industrial robot systems, as they are programmable to perform any kind of machining operation, within certain physical limits, like other robotic systems.

Wednesday, December 17, 2008

CNC Control Computer

The Control Computer generally resides in the shop somewhere near the CNC machine it is controlling. Control Computers don't have to be the top of the line, every bell and whistle type of computer. These are the workhorses. Save your money for a good design computer. You will save much more time having a fast computer for your designing.

A control computer doesn't have to be that powerful for a few good reasons. It doesn't have the workload. It takes G-Code and turns it into signals that it transmits to the Machine Controller. Turning G-Code into signals is not that labor intensive for a computer.

CNC Control
I have used multiple types of control computers. Everything from a 486 DOS running "$30 special" to a modern Dell with Windows XP. I have yet to try one with Vista. I will keep you posted. Generally I like to find a good used computer for a couple hundred bucks, wipe the hard drive and only load the control software onto the machine. That way you know what you have.
There is another good reason you don't want to spend a lot of money here. This computer will usually be located in the shop. Dirt will be located in your shop. Using logic here, dirt will be located in your computer. If the computer does go belly up, you aren't out your children's college tuition.

Here is my strategy in a nutshell for Control Computers. The dirtier the job, the less money I spend on the computer. My plasma cutting computers are bought in the $40 range. They eat a lot of dust and dirt. I blow them out frequently. My wood routing computers are in the $100 dollar range. My milling machine computers usually are in the $200 range. Truth be told, they all last a very long time if you keep dirt, dust and plasma smoke out of them.

How is the CNC Control Computer used?
The control computer has the control software loaded on it. You start up the control software then load up the CNC Program you created. When you do this, the G-Code will be visible and ready to go. Once you prep your CNC Machine and zero it out, you can begin your "cycle." A cycle is usually completing one CNC Program, which is a machining sequence. You will also hear the term "Cycle Time" on the professional side of CNC a lot more. The quicker you can get the cycle time, the more parts you can make. And yes, that translates to more money.

Back in the good old days of Home CNC, everything was transferred on a disk. Now I have seen people include their Control Computers on their home computer network and transfer the files needed wirelessly. At a very minimum, get a good jump drive and transfer things back and forth that way.

CNC has become a very popular hobby and more and more people are starting to hop on the band wagon of CNC. Its a fun hobby and easy to do from your very own home with just a little elbow grease and creative mind.

Wednesday, December 10, 2008

Guide to CNC Kits

Guide to CNC kits
Building a CNC machine means that you would require a lot of tools, parts or different components. Many are built using CNC kits. These are many types of components that need to be put together in order to build a CNC machine.

When building a CNC Machine you need to make a decision on whether you would like to use a stepper or a servo setup. Now, This is one of the most debatable topics in CNC. One tends to get quite confused on what to use, and when to use and why one is going exactly the way it has to be. The fact is that every motor type is capable of providing varied advantages over the other. This actually depends on your applications.

CNC Kits
You would require the following in order to build a CNC machines. All the components mentioned below are usually contained in CNC kits readily available on the markets.
a) Printed Circuit board (Industrial Quality)

b) Drilled solder mask and serigraphy

c) High end electronic components

d) Hexagonal mountings

e) Parallel wires connection cables to PC

f) Connectors to build extension cables to motors

g) Identical stepper motors

h) Software for CNC configuration

i) Manual with step by step guide

j) Power supply 12V 4A

k) Transformer, Diodes electrolytic cap to build your own power

Some tips on purchasing component and building CNC Machines

Tip 1 Make sure that you purchase multiple sets of CNC machine plans

Monday, December 8, 2008

3 - Axis CNC Milling Machine

Grizzly 3-Axis CNC Milling Machine

Technical Details

- Cross travel: 16"
- Longitudinal travel: 31.75"
- Quill diameter: 105mm
- Quill travel: 6"
- Table size: 10" x 54"

CNC Milling machine

Product Description
We want your CNC purchase from Grizzly to be as pleasant and painless as possible. For this reason, an $800.00 "set-up" charge is applied after purchase and after a Centroid technician has visited your location in the lower 48 states to give you or your employees a one day training on the use of the controller. Further, Centroid's technicians will be able to provide support via phone if needed. Visit their website at A Ball-Bar testing report is enclosed with each machine. The bearings used are high precision C7(P4, GMN) class for spindles. They also feature high precision ball screws (C5 class) with double nuts for X and Y axis, Meehanite castings with Turcite for X and Y axis is used in the machines. The beds and knees feature square ways for extreme stability and dovetail ways for the column - all hardened and ground. Spindle speeds are 50-5000 RPM. Auto lubrication, work lamp, coolant system and chip tray are all standard equipment. Each machine is fitted with the Centroid M400 solid state controller with a 15" LCD display. The software included is conversational, with cutter radius compensation, drilling cycles, multi-range spindle and G-code backplot graphics. This is a NICE software package with features that includes LAN connectivity, USB file transfer and high speed "True 3D" machinery.

Tuesday, December 2, 2008

Rockler CNC Shark Routing System

Rockler CNC Shark Routing System

Technical Details

- Travel: X: 24" Y: 13" Z: 4.5".
- Compatible with the Bosch Colt Palm Router.
- Table measures 15-3/4" x 31-1/2"
- 12 precision linear bearing guides (4 on each axis) for maximum rigidity.
- VCarve Pro 3.1 program included ($500 value).

CNC Router
Product Description
Product DescriptionBring the speed and precision of computer-controlled machinery to your shop with this top value CNC system! With a table measuring 15-3/4" x 31-1/2" it's ideally suited for carvings and machining operations on a large variety of signs, doors and other small projects. It boasts impressive power, speed, accuracy, and ease of use. With its robust steel and high-density poly-ethylene construction, it can take accidental impacts that would normally damage or destroy an aluminum or MDF machine. Optional Clamping Table (Rockler# 23369) features two hold-down slots for securing work anywhere along the length of the table. Compatible with the Bosch Colt Palm Router. Includes VCarve Pro software interface a $500 value. You supply a computer with USB port, a Bosch Colt router, and a table top (router and table top also available sold separately). You connect the USB cable to the controller box and the other end to your computer.

Travel: X: 24" Y: 13" Z: 4.5". High Speed traverse rate 120+ ipm. Bearings: 12 precision linear bearing guides (4 on each axis) for maximum rigidity. Resolution: Full step of 0.0005 inch; at 1/8 step 0.0000625 inch. 269 oz/in 1.8-degree steppers. USB interface with on controller memory storage. 5 turn ACME precision modified threaded with acetyl backlash reducing nuts on all axes. 24V Supply to provide full power to the steppers. VCarve Pro 3.1 program included ($500 value). Mounts for a Bosch Router included (Router sold separately) Free downloadable control program included

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