any1 know if they are cheaply available in south africa or have a diagram so i can make them then i will have my ultimate modding machine !!!
There are plenty of free schematics available for both stepper (unipolar or bipolar) motors and servos. I've even seen a couple of G-code interpreters for the Arduino platform. You just need to Google for them.
i know i tried that but i just get those dum european sites wanting to sell me or show me how to build the entire machine and they simply say goto your local electronics store but prob is in southafrica there aint such tihng u gotta search hi and low for sumtin like this please let me know cud i maybe mod the stepper controllers on an old scanner
Modding the drivers from a scanner is unlikely to work if you plan on driving any larger steppers - the steppers the drivers are designed to work with would probably struggle to turn just the screw of any significantly sized cnc.
so wat shud i look for cos like i dnt got alot of money so is there an object that will contain these controllers in and can it be made up and how does it connect to my pc etc and yes i am a noob but im a willing to learn noob
i dnt mind making it up at all infact it wud be nice im hoping there are sum electronic guru's who will be able to tell me how to change stepper controller diagram into one that can interface with my pc
That's just a driver for unipolar steppers (and is less than ideal - you want an H-bridge for bipolar steppers). It has two inputs - SW1 (which would be replaced by pulling the line high or low or using a MOSFET to achieve the same thing from CMOS logic levels) or STEP which advances the stepper one step forwards or reverse (direction determined by SW1). This is how H-bridges work, too. If you have three steppers (one each for X, Y and Z axes) you need to some H-bridges. One for each coil - so six of them for three bipolar stepper motors. It's not strictly necessary, but I'd include some hardware logic gates to ensure certain input combinations can't occur to prevent parts burning out. Sure, you could do it in firmware on your controller board, but logic gates are cheap and you don't want a silly mistake trashing your expensive steppers or burning out your power transistors. You need a power supply for your motors. This depends wholly on what motors you use. 24v or 18v. Rather high currents. It's pretty easy to convert cheap PC PSUs to do the job. You also need a power supply to power your TTL level stuff (this one's easy because it's low power requirements. Probably 5v <1A). Use a wall-wart or a simple buck type switch-mode supply or even just a heatsinked linear regulator powered by your motors' DC supply. While it's theoretically possible to wire your motor drivers (H-bridges) up to a parallel port (maybe include some N-channel MOSFETs and some indicator LEDs while you're at it) and do everything in software, but I'd advise against it. Especially since you don't see parallel ports any more, and it won't work with USB to parallel adapters. Instead I'd do as previously mentioned and look into the Arduino GCode interpreter (it's on the RepRap wiki). Even if you can't buy Arduino boards locally, the design is open source so you can etch your own Arduino board when you do your motor controllers (keep stuff modular, stuff might burn out). You've also got a choice of microcontrollers to use if you can't find at ATMega328 you could use the ATMega168 instead. There's also support for the ATMega8, but you may have serious difficulties using that particular microcontroller. Of course if you wanted you could design your own from scratch based on another platform, but almost everything's done for you if you go with this method. Plus I happen to really like Atmel microcontrollers, and I think the Arduino project is pretty snazzy too. Then there's the software side of things. You need to export Gcode (Mach3 is good), which you could then stream via USB straight to the controller, or if you have some I/Os free you could have your controller read the Gcode from an SD card or over ethernet and remove having to have a computer sat around to just control your CNC router.
WOW nice reply!!! i am l0oving all the dataz i have here cos alot of those online guides suggest unipolar motors but now to think of it that wud be stupid becuase id need to drive the motor back and forth on each axis! anyway i have found a place dwn here by me that can make pcd bords and they give me a negative so once i have made them i will gladly mail u a copy of the negative... but i would like a simple circut diagram to show me how to make it becuase importing these controllers will cost me 150$! each but the flip side is a local super store near me is having a special on a 1200w router so ima be buying that
"Unipolar vs Bipolar" goes a little something like this: Unipolar motors are easier to control (no center taps so it's like you have fewer coils to worry about). Bipolar steppers have a 'simpler' construction internally, and as such are more efficient. They are faster and higher torque. You could always mix and match - since the Z-axis has a shorter travel you could use a cheaper unipolar stepper for the Z-axis and faster, higher torque motors for the X and Y axis. What you have to think is you build your motor controller once, but you may be sat waiting for your tool to move around for hours a day, so you want it to be as fast as possible. With a home built machine your ballscrews/leadscrews will have more friction than a commercial machine (probably) - so you need more torque. Which is why I would suggest using bipolar stepper motors. Beside, there are single chip drivers available which make building a controller trivial. The L6208 springs to mind - 4 outputs at up to 50v, 5.6A for bipolar steppers. Not too bad for about £11 or so ($17) plus the cost of a dozen resistors and capacitors and a small heatsink. And that will handle a bipolar stepper without having to mess around with power MOSFETs and snubber diodes to build a pair of H-bridges. Here's an example of some L6208s in use, it's in French but a Google translation should give you a good idea on what's going on. Unfortunately, if you're looking for a simple diagram, you won't find one. It's simply not a simple subject. If I were you, I'd start off with some serious planning. What sort of working envelope do you want? Fixed gantry with a moving bed, or a static bed and moving gantry? Spindle power, speed and size to take into consideration - what sort of materials do you want to work with? What sort of construction will you use - metal profile like 80/20, bolted plate/bar/tube stock? Will you weld it (hard to maintain alignment, remember)? MDF perhaps - this design may allow you to machine a second larger more durable machine from aluminium? How much can you afford to spend on each part? Do you already have all the tools you need - squares are very import, do you have an XY vice for your drill press? Once you have a very good idea of the machine you want to build, start with what leadscrews/ballscrews and rails you've picked (or maybe you're going with a timing belt/chain and sprocket drive!?) - the length, size and pitch will allow you to pick suitable motors. Once you've picked the motors you can choose a design for the power supply and motor controllers.
ok i have an entire aluminim factory at my disposal lathes, end routers, end milelrs cut off saws drill press's cut of saws and a crap load of scrap aluminuim profiles and i would like a fixed bed design with movable ganty so which i will soon design in sketch up and post here but electronics are my main problem at the moment but another thing.... i am not sure if you wil know what im talking about.... but my friends works at a comercial printing compnay really really big printing machines like 3 stories high (i ment huuuuge) and i wanted to know will the stepper motors from there work? or are they adaptable.... and well where are those drivers available from and is shipping available to south africa? regards ian
http://za.rs-online.com/web/search/...Ne=4294954291&N=4294943136&productNum=0456438 RS stock Arduino boards too. I can't personally recommend the South African division of RS, but I've used RS in the UK and they're a good supplier. As for whether those particular steppers would be suitable, you'd need to get a model number. Take a look at CNCzone.com to see the sorts of specifications people are using.
i had a look at that l6208 its just a lil chip wht else is needed with that and how do i connect em all up and also take a look here are these worth it http://www.cnczone.com/classifieds/showproduct.php/product/4150/title/steppers-2c-controller-2c-lovejoy-joints-2c-all-electronics/cat/7 http://www.cnczone.com/classifieds/showproduct.php/product/4014/title/fet-4-and-stepper-motors/cat/7
Read the datsheets - they come with example circuits. Or use Google. Or look at that link to the French page I gave you - there are circuit diagrams included on that page. How long is a piece of string? It depends on what you want to be able to do with your machine. I wouldn't touch the kit from the first link - it's only really powerful enough to route wood.
ok mr expert tell me can i create 1 controller that controlls all four and then have that hooked up to my pc without anything inbetween ? (i did abit of reading i r smarter now)
You would have as many L6208 (for example. Or scratch built H-bridge) circuits as you need stepper motors (probably 3), one circuit (probably a microcontroller based solution) which receives instructions from the PC and sends them to the motor drivers and receives inputs from limit and home switches and an emergency stop button (or you may want to switch main power for the eemergency stop). You could etch everything onto one circuit board if you wanted, but it'd be a very large board and it would be a pain if any one part breaks. I'd much rather have a few smaller boards that can be replaced as necessary. Then just join them together with IDC connectors and ribbon cables for data and either banana plugs or screw terminals for power stuff. There are a few guides to building CNC controllers on Instructables.com and over in the CNCzone forums.
hi omg dude you need a bit tech merit found an awesome guide on intractable.com and all the parts are available in my country and my fathers old work was a commercial paper printing firm and well luckily i know the guy in charge of the electronic section and to make you realize the size of the machines im getting motors off it is 3 stories high and its motors are capable of moving printing heads/ folding contraptions at speeds of up to 9 m/s so would a motor that is too fast be a problem? or would this just be better? so hopefully ill have pics of the liner frame soon i wont waste time doing sketch up im just going to go and do it i have a tone of machinery at my disposal but cash flow is a problem cos i have no knowledge of how strong these motors have to be and some companies are telling me each motor will be like R 5000, 00 which is like the equivalent of 500 pounds! so like some stats if my gantry will be made of aluminium frame and will be 3-4metres wide (width of my table) and where cud i scavenge these motors... peace out and rock on
The problem with using huge motors (apart from the cost) is they will require a lot of power to move them - your drivers will have to be very powerful (and hence expensive, and possibly tricky to find parts for). Don't forget you've also got to mount them. I was expecting a first build to be much smaller. Something like this one: Or like this build.
For an easy solution, check this out - it's easy to build, reasonably cheap and comes with all the bits you need. There's a very lively discussion board if you have problems getting it to work. And if you want to avoid the hassle of worrying about motors, he also does a all-in-one package. Oh, and he'll ship anywhere too.
hey guys those look awesome ! i think i will order them luckily my father wants them built just as bad as i do so maybe he will give the funding for the all in one kit then ill spend a few weeks at his worshop setting up a pretty decent gantry/table and once again thanks for the links and my mouse has a broken scroll button its so annoying 1 bit down 2 bits up :\
