Hope this is the right place for this... I am interested in controlling a large amount of stepper motors - like 540 of them in a 27 x 20 array. Thanks for any insight on where to begin.
dmen:
Hope this is the right place for this... I am interested in controlling a large amount of stepper motors - like 540 of them in a 27 x 20 array. Thanks for any insight on where to begin.
Is this just a thought exercise or are you serious? If serious, draw a schematic of how you will wire these together, including the controllers. Then compute the power required to run the steppers.
Paul
Thanks, and yeah I am being serious. Have a look at the Brixel:
I figure it must use steppers... right? Every brick is individually controllable.
I am asking here to get some insight - I don't know what controllers I would use... or even what steppers. Just getting thoughts together so far.
dmen:
Thanks, and yeah I am being serious. Have a look at the Brixel:
https://www.youtube.com/watch?v=Z-5cVpWhp30I figure it must use steppers... right? Every brick is individually controllable.
I am asking here to get some insight - I don't know what controllers I would use... or even what steppers. Just getting thoughts together so far.
To duplicate that would take about $100,000 plus 5 years. Do you have both?
Paul
The question was not about money, or time, and I'm sure it's quite a lot more than $100K. Where might I find info on controlling that number of motors?
dmen:
The question was not about money, or time, and I'm sure it's quite a lot more than $100K. Where might I find info on controlling that number of motors?
You control one motor at a time. So did the video. When you can do that, then do 2, then 3, and so on.
Paul
Gee that's helpful AF. I can control one motor now. I am wondering how to control 540 since a single Arduino Mega can do like 48 max... so am wondering how to break it up. Anyone else care to be actually helpful?
Wake up and study the video. What do you see the mirrors doing? A mirror is moving to a position and then moving again. Simple stepper control.
Now, the design problem for you to emulate is how to control and sequence the controllers.
Paul
I guess I will try elsewhere thanks. Maybe Adafruit forums... I already said I can control a stepper motor with an Arduino. I do not understand how to control 540 of them since a single Arduino can only control 48. Which I also said...
dmen:
I guess I will try elsewhere thanks. Maybe Adafruit forums... I already said I can control a stepper motor with an Arduino. I do not understand how to control 540 of them since a single Arduino can only control 48. Which I also said...
Let me try again.
The stepper control are simple movement. Think one Arduino per stepper. Each Arduino is programmed to make 16 different movements, based on serial input data. Each Arduino responds to an address in the message text and moves it's stepper to the commanded position. That is ALL it ever does.
Some giant computer is programmed to send messages to the Arduino controllers to control a sequence of movements. That is where all the intelligence and programming skill is applied, not in simple stepper movements.
Paul
Paul_KD7HB:
The stepper control are simple movement. Think one Arduino per stepper. Each Arduino is programmed to make 16 different movements, based on serial input data. Each Arduino responds to an address in the message text and moves it's stepper to the commanded position. That is ALL it ever does.Some giant computer is programmed to send messages to the Arduino controllers to control a sequence of movements. That is where all the intelligence and programming skill is applied, not in simple stepper movements.
That's my take on it also.
Maybe one Arduino controls 2 or 4 motors, but not more. But the Arduinos would be the cheapest part of it.
...R
OK, thanks much to both of you. I still don't understand the controller part though. If I can control more than one stepper with one Arduino, why wouldn't I? I thought I can control 48 with a Mega? But - so even if I assume I control one stepper per Arduino - how does one go about hooking up 540 Arduino's to one computer? Just the sheer number is what's perplexing me. Thanks.
Or wait - All the Arduinos on the same Serial bus? They each have different software that reads the header or whatever and only responds to it's address? That makes a little sense to me I think.
PS - I also found that that a Brixel begins around $450K to purchase.
You really need to start studying some of the videos on the mikeselectricstuff youtube channel - his company
mainly do light based projects, but the principles of controlling 10,000 LEDs are the same as controlling 10,000
motors.
PS - I also found that that a Brixel begins around $450K to purchase.
And if they are using steppers, extremely power hungry. I suspect they are wise to that and use
servomotors.
dmen:
OK, thanks much to both of you. I still don't understand the controller part though. If I can control more than one stepper with one Arduino, why wouldn't I? I thought I can control 48 with a Mega? But - so even if I assume I control one stepper per Arduino - how does one go about hooking up 540 Arduino's to one computer? Just the sheer number is what's perplexing me. Thanks.Or wait - All the Arduinos on the same Serial bus? They each have different software that reads the header or whatever and only responds to it's address? That makes a little sense to me I think.
PS - I also found that that a Brixel begins around $450K to purchase.
You are getting there a bit at a time. All Arduinos are actually custom boards that include a driver for a single stepper. All of these boards are identical and contain a 4 position DIP switch that is set to a different number for each board. All the software in the Arduino is identical. The DIP switch tells the software where to look in the control message for that boards command.
Think of trying to service that many boards when all are different and have to have various wires attached.
For communications, I would use something like a 20ma current loop that goes through each and every Arduino board.
For control, I would use a 540 byte message. Each controller would look at it's byte, based on the DIP switch, for where to move it's stepper, and do the move.
A PC would control the whole project by sending the 540 byte message with the current position for each stepper. All kinds of PC programs could be used or could contribute to the value of each byte.
IF you want to continue, engineer the way a stepper can move one of the stacked bricks, but keep them in vertical alignment.
Paul
MarkT:
And if they are using steppers, extremely power hungry. I suspect they are wise to that and use
servomotors.
Looks like it is steppers with Trinamic drivers.
I also found that that a Brixel begins around $450K to purchase.
hahaha! I think that is an 'asking price'.
$450k /540= $833 each!
I'd guess each one is about $100 to manufacture. I wouldn't go over $150k for the whole wall. 
(and I'd be asking for a 10 year warranty...those 'slip rings' give me concern)
I would have built it using coaxial tubes nested together, different tube for each brick, with ball bearings between each brick. All the driving mechanism would be in the base. No slip rings. Use rubber belt between stepper and the associated tube. Much more mechanical work.
Paul
Paul_KD7HB:
I would have built it using coaxial tubes nested together, different tube for each brick...
20 coaxial nested tubes?
I'll take "Designs that would never work" for $100, Alex.
A fuller viewing of the video reveals that the slip-rings was just an idea that was rejected (prototype 01).
By prototype 04 there are no slip-rings.
1 Like
Paul_KD7HB:
I would have built it using coaxial tubes nested together, different tube for each brick, with ball bearings between each brick. All the driving mechanism would be in the base. No slip rings. Use rubber belt between stepper and the associated tube. Much more mechanical work.
What about having a motor, Arduino and wireless receiver and ESP8266 inside each "brick" and rotation around a fixed column ?
...R