Before I say anything at all , I have to make it very clear that “ I am no expert at CNC ”, but I do have quite an interest for it and have managed to get some very rewarding results out of the many hours I have put into it .
My interest started about 15 years ago after seeing a kitset CNC router unit from a company called Step four in Europe . I ’ m not sure if they even exist anymore , but it did get my attention towards building my own . For quite a few years I have been playing around with stepper motors out of old printers and trying to get some sense out of them with little success , but more recently this has turned around . So over the next couple of editions of Model Flyers World I will share with you what little I know of it .
So , what is CNC ?
CNC , or Computer Numerical Control is where you can take control of a machine such as a mill , router , laser cutter , plasma cutter , lathe etc . and drive the multiple axis of these machines to very accurate tolerances by computer commands . Additionally these actions can be repeated multiple times to obtain perfect repetitious quality of the parts you choose to make multiples of . Some of the larger , more complex ( and e x p e n s i v e ) c o m m e r c i a l m i l l i n g machines are operating 6 axis control of the cutter head , giving them basically infinite access for those intricate jobs . The compressor wheel in my Jetcat turbine engine is machined from a solid piece of aluminium by one of these six axis machines and can be seen in this You Tube video clip : http :// youtu . be / 5Vojok45Q-c But the more simple router machine I have built controls the three basic X , Y and Z axis , which I find more than adequate for what I need to do . More about this later .
Where does it all start ?
The CNC machine , like most computers , is quite dumb until you as the operator give it the commands of what you want it to do . To do this we use a CAD ( computer aided drawing ) or CAM ( computer aided manufacturing ) program on any desktop or laptop computer to draw the component we wish to make . The level of drawing is really only limited by your imagination and most probably quite a few of you have already had some hands on experience playing around with CAD drawing programs of some sort . However , unlike a lot of CAD programs out there , this program also needs to have the added ability to generate a specific code called “ G Code ”. It is this code we then put into the CNC machine to give it the commands of operation . If I have now sparked your attention , you can download a free version of a CAD / CAM program called CAM BAM , which also generates G code . When I say free , I really mean you can use it for 40 times before you have to pay for it to do any reasonable size job , but this will give you a taste of it with plenty of time to decide if you want to go further with it or not . It also has a few very good video tutorials to view before you download it , to see if it is right for you . Have a look at : http :// www . cambam . info /. There are many similar programs out there to use , but I have found this one to be pretty straight forward for getting
Top : Router table computer terminal Middle : 1300mm X 900mm Router Table Above : The brains of the table . Upper right corner is the 48 volt power supply with the 5 V plug pack in the power point below . The clear plastic box on the left provides ventilation to cool the 4 stepper motor drivers and has the breakout board mounted on top of it in the lower left corner .