Arduino ?

[Tin Falcon]

Arduino is now offering motor shield modules(controls ) a single stepper and relay shieds 4relays on the board. Wondering has anyone here used the arderino for cnc and how it is set up and how well it works .
I know tom was doing some arduino work making his own board.
mostly curious I need to use my cnc before I think about more experimenting.
I am thinking about the relay board though cheap $20

Tin

 

[n4zou]

I think you mean Arduino. I've been looking at this system for a while now but I haven't jumped in yet. If you don't mind slow shipping Deal Extreme carries most all the Arduino modules at discount prices. Shipping is free (so I guess that's why it slow). Typing in "Arduino" in the search block brings up all the Arduino modules they stock.

http://s.dealextreme.com/search/Arduino.html?page=1

 

[Tin Falcon]

One of the radio shacks I visit has a good selection but higher prices.
Hmm
Interesting stuff but do not need another hobby.i do electonics work so could be interesing upgrade of knowledge
Tin

 

[cfellows]

I've been messing around with the arduino some but haven't bought a motor board yet. I've been wanting to experiment with steppers and servos.

The arduino board is good because it will support up to 2 amps per channel. So far I haven't found one domestically for less than about $35 if you include shipping.

There is another board available from ladyada that has two servo connects as well as stepper and/or dc motor connections. Unfortunately the board only supports up to .6 amps per channel which is too low for me. However, the servo connections could also be used to drive the electronic speed controls for brushless DC motors, another interest of mine.

http://www.ladyada.net/make/mshield/

There is another, separate board available from an eBay seller in New Jersey that looks reasonable. It's only $10 with free shipping. It's not a shield, but should still be easy enough to use:

http://www.ebay.com/itm/L298N-Stepper-Motor-Driver-Controller-Board-for-Arduino-/160730209683?pt=LH_DefaultDomain_0&hash=item256c445d93

Anybody see anything wrong with the second one?

Chuck

 

[Tin Falcon]

the $10 looks cool. and certainly cheap enough. probably a better option than the motor shied. the motor shield will take 2 amps but only 12 volts max 9 recommended. so motors will move pretty slow.
You may want to keep an eye on radio shack they are offering an increased variety of kit DIY products again. vanderman , stamp and arduino.
Tin

 

[Bluechip]

I've been messing around with the arduino some but haven't bought a motor board yet. I've been wanting to experiment with steppers and servos.

The arduino board is good because it will support up to 2 amps per channel. So far I haven't found one domestically for less than about $35 if you include shipping.

There is another board available from ladyada that has two servo connects as well as stepper and/or dc motor connections. Unfortunately the board only supports up to .6 amps per channel which is too low for me. However, the servo connections could also be used to drive the electronic speed controls for brushless DC motors, another interest of mine.

http://www.ladyada.net/make/mshield/

There is another, separate board available from an eBay seller in New Jersey that looks reasonable. It's only $10 with free shipping. It's not a shield, but should still be easy enough to use:

http://www.ebay.com/itm/L298N-Stepper-Motor-Driver-Controller-Board-for-Arduino-/160730209683?pt=LH_DefaultDomain_0&hash=item256c445d93

Anybody see anything wrong with the second one?

Chuck

Hi Chuck

Mine worked OK-ish ???

http://www.ebay.co.uk/itm/L298N-Ste...ial_Automation_Control_ET&hash=item4ab3c3da44

Look familiar ?? Apart from the price

The heatsink is nowhere near adequate though.
Used mine on a 15V 0.8A/phase bi-polar stepper.
Got very hot, so a fan was rigged up after I dropped it to 12V.
I should point out it did not fail, just not happy with the temp.

What do you propose to run off it?

Dave BC

 

[Mawitö]

Hi, here you have another shop with free shipping, this one has a lot of arduinos alike and shields, cnc products etc.

http://www.goodluckbuy.com/

Arduino is a really nice platform, lots of information, and works really nice for cnc projects, take into account that most opensource 3d printers use some kind of arduino as a 'brain', i even saw some projects of a stand alone controllers where you can put your gcode files in a sd card.

http://www.contraptor.org/motion-control

here you have a little more info on the layers needed to make it work.

Mawito

 

[cfellows]

Hi Chuck

Mine worked OK-ish ???

http://www.ebay.co.uk/itm/L298N-Ste...ial_Automation_Control_ET&hash=item4ab3c3da44

Look familiar ?? Apart from the price

The heatsink is nowhere near adequate though.
Used mine on a 15V 0.8A/phase bi-polar stepper.
Got very hot, so a fan was rigged up after I dropped it to 12V.
I should point out it did not fail, just not happy with the temp.

What do you propose to run off it?

Dave BC

Hi Dave, Yep, that does look like the one I saw. I mostly want to experiment some, but as a first project I would like to build an arduino powered dividing head. I would likely gear it down quite a bit to increase both the resolution and the torque since speed isn't really important. Therefore I wouldn't need much voltage / current, but I would like to have enough capacity for other experiments as well.

I'm planning to use a salvaged PC power supply for power. That will give me both 5 volts and 12 volts with plenty of amps. Turns out there is more to that than I thought, as well, but I'm getting there. Since the PC power supply is something called a switched power supply, you need a load across one of the 5 volt leads and ground. Then to turn the power supply on, you have to short out or put a switch between the green wire and ground. Right now I'm just trying to get all the wires from the power supply hooked up to terminals I can attach leads to.

Chuck

 

[Bluechip]

Hi Chuck

You should be OK. Best of luck with the ATX supply, you may find you have to load the 12V output as well to get it to power up. Been driven mad by the things, one refused to play, desite the fact that it worked fine when put back in a PC.. Grrrrr... Never did get that one to co-operate .

Lots of stuff on the net about using them for other uses apart from PC's.

You should be aware that the L298 cct. board is minus it's companion chip, the one that controls the drive current.

The L297 !

I don't know how far you want to go with this stuff but if you download the .pdf for the L298 it gives the cct. for the pair screwed together.

http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/DATASHEET/CD00000240.pdf


Fig 8

I can't find my board to check, but I don't recall it being on there.

Make my own PCB discrete drivers now. Ugly, but easy to fix ..

Dave

 

[John Rudd]

Short the green wire to ground( connect the green to black ) to power up the power supply, connect a 21watt lamp onto the 5v output, then use the 12v rail to power whatever....

The 5volt rail is the important one as the other supplies 'track' it...

 

[geoff p]

I've been diddling about with Arduino for some months, trying all sorts of daft ideas.

Trying to drive two dc-motors for a caterpillar-tracked vehicle, I made a separate driver-board. It uses an L298 chip (anywhere from 2 dollars to ten dollars, from your local electronics store if you are lucky), which takes two digital-signals on each of two channels and can handle 2 Amps from a 50~55 Volt supply. (See later.)

Since a bi-polar stepper-motor requires two-signal on each of two channels, I thought to try my driver with a stepper-motor. It works! OK, it has enough 'welly' for one axis of my pseudo mill. Let's make a second board. Ha! Now I have X- and Y-axis control.

Programming the beast is another matter. I tried sending my 'G-code' file via the USB port, i.e. read-a-bit, act-on-it, read-a-bit etc. with very spurious results. The problem (for me anyway) was to control the flow of data so the machine could execute long moves before reading the next chunk from the file.

Eventually, I could drive my table around a circular path - well, sort of, by some definition of the word circular.

Yesterday, I jury-rigged a tiddling ex-printer stepper to the long-axis of my lathe and, after some fiddling-about, got it machining the bore of a cylinder to a most beautiful finish. The Arduino didn't care, nor get impatient that the cut was taking fifty-minutes. Meantime, I got on with browsing the Internet.

As for power-supplies, I just use wall-warts at 12V, 1Amp.

Geoff

 

[cfellows]

Nice, Geoff. Did you design your own driver or use someone else's circuit? That stepper on the lathe bed looks mighty small. What's the voltage and amps your driving it with?

Thanks much...
Chuck

 

[RonGinger]

There is an Arduino based controller for the Reprap, 3D printers. It reads Gcode and drives the stepper motors. No reason it couldnt equally well drive a CNC conversion. There are a couple version , and some are sold as ready to run boards. They are all open source.

I have not used any of them, and dont recall specific names, but google reprap and arduino and you will get many hits.

 

[geoff p]

@Chuck, Yes the stepper IS mighty small - but then, so is the lathe I'm driving it with about 12V and the amps are just whatever. The chip + heat sink get a bit warm so I aim my room-fan in the general direction of the lathe and Arduino.

Yes, the board is my own design - I attach a Jpeg of it but don't try to print from it, the quality just isn't good-enough. I use Xara.exe for my designs - can't get my head around AutoCad, SolidWorks etc. - but for what it's worth, I'll also attach a PDF file. (This forum can't accept .xar files. Fair enough.) The view is a 'reverse' of the copper-side of the board, so the black ink will be in contact with the photo-resist and there is no parallax. Sorry, messy explanation.

My board does NOT give current-control and it does require properly sequenced signals. I found that (Arduino library)/stepper.h works adequately, especially at slow(ish) speeds. AccelStepper.h works very well for higher speed but can be a bugger to set-up.

A much better 'jobby' is to use an L297 to A/ decode Step & Direction & B/ set/control the motor-current, followed by L298 to provide power to the motor. I have built several in the past but I'm jiggered if I can find any just now.

Personally, I wouldn't buy a motor-driver board specific to Arduino - there are plenty of makers 'out there.' Ocean Controls (Australia) www.oceancontrols.com.au are one company I have had superb service from in the past.

Geoff

View attachment Arduino L298-only.pdf

 

[cfellows]

I took the plunge and ordered one of these:

http://www.pololu.com/catalog/product/1182

I think it has everything I need, including a current limiter to the stepper which should come in handy. And, it's pretty small...

Chuck

 

[geoff p]

@Chuck,
Looks good! Since it doesn't sit on-top-of the Arduino, and requires only Step and Direction from the Arduino, you could connect multiple copies of it and control several stepper-motors, e.g. X-, Y-, and Z-axis, (and still have Arduino I/O-pins left over for other tasks.)

As you are unlikely to even want to change the micro-stepping in the middle of a move, hard-wire the MS1, MS2, MS3 directly on your Polulu board, as appropriate, without them even going near the Arduino.

Geoff

 

[cfellows]

Thanks, Geoff, that's what I was thinking. I may eventually want to build this into a self-contained enclosure with a keypad input and an LCD display. These latter two will require lots of pins from the arduino, so minimizing the number needed for the stepper will be a big help.

Chuck

 

[n4zou]

I've been looking at Arduino and Electronic Lead Screw (ELS) http://www.autoartisans.com/ELS/ . ELS has become a mature system that I could order and hook it up without doing much of any real work like programming. I could even buy a ready to install box. Arduino would be more of a challenge but not really that much as most all the source code required is available. I'm not really even sure I need the help of a gadget box. I did a little CNC work before I joined the military and retired after 25 years. I really enjoy machining parts and standing back watching a gadget box do it for me takes me back to my trade school days when 3 or 4 of us had to share a machine. Standing back watching someone else having all the fun while waiting for machine time was boring in the extreme. Sitting at the computer punching out G-code is something I never liked very much. That is what is appealing about ELS. It's more of an assistant than a robot.

 

[cfellows]

I was member of the ELS forum for a long time and watched closely while it was being developed. I do find it interesting but it doesn't suit my needs. I'm not really trying to build a CNC system. Rather, I'm just wanting to learn about the programming and electronics of interfacing the Arduino with electronic and mechanical devices. It's the building and learning I'm after... the end product is just a bonus, assuming it works! :-\

Now that I think about it, it's kind of amazing how many different things I've gone to a lot of trouble to build, only to put it on the shelf and rarely use it once completed... go figure.

Chuck

 

[geoff p]

A man after my own heart, Chuck.

Now that I think about it, it's kind of amazing how many different things I've gone to a lot of trouble to build, only to put it on the shelf and rarely use it once completed... go figure.

I have always enjoyed dabbling in electronics - I bought my first transistor, an OC71, back in 1962 (not that long after they were invented) and I still remember crying when I blew it up!

My first lathe came as a swap for my Dad's old anvil, so I had to begin learning to make swarf. A set of steam-engine castings was made from milk-bottle tops, melted on the gas cooker.

When a friend gave me parts of an old, oak table-top, I just had to build a (wood) lathe to turn the legs. But I couldn't get them even vaguely similar by hand so I made a copying attachment, utilising my near-forgotten electronics.

To make it more versatile, the computer could probably control both the cutter (Z-axis) and the 'saddle' (X-axis). Enter another bout of learning, which ended up with making a 3-axis, CNC router balanced on a washing-machine casing.

Nowadays, I combine woodwork (for pattern making), foundry (for my castings), mini-lathe (for machining) and Arduino because it is flexible (and reasonably forgiving.)

Geoff