Thread: Camera slider

Geoff, thanks for the anarduino link. Pretty cheap, and good shipping. Will keep them in mind if I need a wireless project.

Pippin88 and Snowyskiesau, very interesting re the Arduino pro mini. Have either of you gentlemen used the mini to drive a stepper motor?

I have just ordered a nema 17 stepper .4A per phase, 200 steps bipolar. This is motor I would like to drive using a 12v battery.

Ken

I've a 3D printer that is Arduino based and uses steppers but hardware and software designed by someone else.

I did come across this article about stop motion with an Arduino. It's a tutorial on the code and how it all works, might be a good place to start.
For a complete slider controller solution, there's this one http://www.minie.airiclenz.com/about-the-miniengine/

Thanks SS, that looks like a great article, something to do tomorrow instead of wasting money trying to pick the Melbourne Cup winner.

May I ask what on earth can you make with a 3D printer that's actually useful?

Most of the stuff I've seen looks like a pile of pixelated plastic that would break easily.

Ken

Let me add my 2c, firstly regarding printed parts, attached are a couple of photos showing bearing mounts that I drew up and a mate printed for me with his printer, funnily enough for my 3D printer build, pretty sweet, just tap the bearing in, which is quite a tight fit, and bolt it in to the machine, what more could you ask for ?

As for the slider (which a 3D printer could make a lot of parts for by the way) I can see two options that I would pursue, either use a simple pulse generator, something like this : http://www.ebay.com/itm/181096913621

This could be mounted into some sort of enclosure (possibly 3d printed...sorry couldn't resist) and connect the output to a standard stepper drive, like a Gecko G251. Pro's would be simplicity and cost, Con's would be control, or lack of, speed would be adjusted by eye, which may be good enough for your needs, or maybe not.

Or...

Use some kind of Arduino, PIC, or any of the million other flavours of microcontroller to provide more intelligent control to provide the pulses to the stepper driver (again I would stick with a G251) Pro's would be exact control, still not too epensive in the scheme of things, Con's would be you need to program the thing, or con somebody else into doing it for you.

Another option that might be the simplest is to use a DC motor and a PWM generator ( I m sure somebody has already mentioned this in one of the threads) simply geared down and speed control by turning a volume type knob. the ebay Pulse generator I already linked would work for this. Again the thing needs to be adapted by somebody.

Good luck.

Russell.

Thanks epineh for the link to the 555 timer module. Couldn't go wrong for that price.

Funnily enough today I spent researching circuits involving the 555 timer and a decade counter to drive a stepper motor. Google turned up many simple circuits.

Certainly looks like a viable way to go without the hassle of programming.

I chose the Arduino and Adafruit combination simply because it looked really cute, and if I could get a handle on the programming, I could use it for something else when my son looses interest in the camera slider.

Out of interest, how long did it take to print the bearing blocks? How does that compare time wise to turning them and milling the holes?

Ken

The basis of this project has actually surfaced a few times in different guises, positioning fence for a router table, or circular saw... hard stop for a guillotine, sawmill travel and so on, basically all needing to move one axis to a certain position accurately and with minimal hardware.

It is on my to do l list, but I need some other projects finished first, same old story, lol.

From memory I think the blocks took about 15-20 minutes each to print, I was a bit sceptical about printers myself until I saw what my mate was doing, and I can see a lot of other uses for one, which is why I am building one for myself. First project will be to make custom encoder mounts for my milling machine servo's, basically otherwise I would need a chunk of 80mm aluminium turned down, and mounting holes drilled, amongst other things, I would guess at least a days work for somebody who knows their stuff and has a lathe to make three mounts, I don't have a lathe nor do I know much about using one, lol.

Also the printer does the work, I am free to drink coffee, beer have a nap etc

Cheers.

Russell.

I'm working on something other than a camera slider but here's some bits and pieces that could be used for one.

Shown is an Arduino Mega which is compatible with but more powerful that the Uno.
With it is a stepper motor controller I've just assembled. It's shown with 2 stepper drivers ( the small white boards) but can take 4 drivers if required. These particular drivers can handle a steady 1.5 Amps with a peak of up to 2.2 Amps if a suitable heatsink/fan is used.

I've also thrown in an image of a piece of Makerslide with a carriage fitted. This particular bit is 1 metre long but you can get it in lengths of up to 2,8 metres.

Total cost for the electronics is around $42. Makerslide is ~$25 per metre , add another $15 for the carriage and wheels.

Hi Snowy,

I'll follow your project with great interest. What are you working on?

Have you got a handle on programming the Arduino, I'm struggling to get past first base.

It's all double dutch to me, probably have more luck deciphering Egyption hieroglyphics .

Ken

It's for a small CNC router called the Shapeoko.
Rather than buy the bits, i thought I'd make as much as I can.
Next task is to route out the metal plates on the CNC router at the local hackerspace.
I already have the Makerslide and the various belts and pulleys, nuts, bolts etc.

A few days ago, I ordered an Arduino compatible uno R3 board from Core Electronics, and it turned up this morning. Wow, that was almost as quick as going to the shop.

My godfather, I had no idea they were so small, you almost need a magnifying glass to see some of the components.

The genuine article cost around the $25-30 mark, I paid half of that. The quality appears excellent.

There is an excellent Arduino tutorial that walks you thru many basic examples getting more complex as you go.

I've just run the example "blink" to test out the board, and all seems fine.

It took a little while to install the Arduino software and locate the drivers, about 20 minutes.

Reckon I'm gunna have some fun if I can interpret the sketches (programs)

Ken

For those of you champing at the bit wondering how my camera slider project is progressing, it's not. No, that's not quite true.

As an update I have an Arduino compatible uno R3 board, an Easy Driver board, a mini breadboard and a bunch of leads, leds, etc and a nema17 stepper motor.

The Easy Driver board was dream't up in collaboration with Brian Schmalz, and it's Brian to thank for the stepper motor sketch No.5 here.
http://www.schmalzhaus.com/EasyDrive...rExamples.html

Basically it's a sketch to drive a stepper motor forward with stop and reverse, plus speed. It's all there except for one thing, limit switches.

What I'm attempting to make is basically a linear actuator, stepper driven with a timing belt. At each end of the aluminium track will be a limit switch, and herein lies my problem.

As soon as the carriage hits the limit switch, the motor is instructed to stop, and whilst it's sitting on the limit switch arm, the motor can't be reversed.

If anyone can solve this problem with Arduino code, beers will be involved.

I've had a lot of help from Brian Schmalz, but currently he is on leave and I dare not interrupt his lying on the beach, pina colada's in hand.

Sadly I've had little joy from the Electronics forum and the CNC forum.

All the smart fellas seem to be here, except me!

Ken

How are you implementing limit switches? The sketch you linked to doesn't mention them.
In CNC code it's common to sense the limit switch and then reverse the motor until the switch opens and that's the home position.

Hi Snowyskyiesau,

Correct, there are no limit switches in tutorial No.5 that I linked to.

Snowy, I was thinking along the same lines as you, ie, hit the limit switch, then back off a tad and stop. I don't know how to code this.

If you have time, I'd appreciate you having a look at tutorial No.5, maybe print it out, and describe what lines of code you'd pop in there to do the above.

This is doing my head in, and I thought having an Arduino would be fun.

I haven't actually wired all this up yet, that's my next step.

I did read somewhere that hitting the Arduino reset button overcomes the problem of the closed limit switch. Can't see it myself.

Ken

edit

Here is an explanation from Brian Schmalz on how the button sequence works, in particular "stop"

I'm assuming you're referring to the Example 5 code from this page: http://www.schmalzhaus.com/EasyDriver/Examples/EasyDriverExamples.html

Each time through the loop, we create a value called current_speed, which is sent into the setSpeed() call to set the new speed for the stepper motor. To make the motor stop, we simply set current_speed to zero. To calculate the value of current_speed, we read the analog input, scale it, then multiply it by the variable called sign. If sign is +1, then our current_speed will be in a forward direction. If sign is -1, then current_speed will be negative and will make the motor go in a reverse direction. But if sign is zero, then current_speed will always be zero, and that will stop the motor.

Does that help?

If all you want to do is have two (or more) switches actually stop your motor, this should be very simple to do. Simply add code to read the new switch inputs, and set sign = 0 any time any of them is pushed. That will stop the motor.

And a very merry Christmas to you too!

*Brian

Home www.schmalzhaus.com
Work www.logicpd.com