I should make the premise that I am not very familiar with the world of robotics and servos.
I have some experience controlling stepper motors with Arduino but nothing more.
What I am interested in now is building a small motion control system to synchronize small scale special effects.
Here’s a description of what I would like to control and what I would like to achieve.
I would like to control:
2 or more Servo motors at the same time
2 or more Stepper motors at the same time
6 or more on/off electricity switches (solenoids?) (12V and 24V)
Through means of computer software I would like to be able to:
independently trigger, set specific speeds and rotations for each of the motors (including ramp-up and slow down)
independently trigger the on/off electricity switches and being able to decide for how long they will be on/off.
synchronize the motors with the switches, for example being able to trigger motor 1 then after X milliseconds trigger Switch 1 than after X milliseconds trigger motor 2, and so on.
allow the whole programmed/synchronized motion control system’s “timeline” to be triggered by an outside voltage signal of 24v.
Is it something achievable? Is this something you can help me put together?
I don’t have the knowledge as far as what components I need but I do know exactly what I want the system to do and can provide all the specific information to give you a better picture.
Finally here’s a list of what I am aware I need to buy:
Computer (do I need a PC?)
Software (What kind?)
1 servo motor that can handle heavy loads. ( I can be more specific as to what I need to move later on)
I hope you can help me identify the other components needed to make this system work.
Thank you in advance, if you need more information I would be very happy to provide them to you promptly. I will be checking the forum obsessively.
I’d consider using a CNC control program to do what you ask.
More accurately, the motion control system underneath it. Research motion control, their commands will control motors and switches. You may want to drive the commands with a script, I.E., a CNC control program or the like.
Thank you for your advice, it is definitely of help to me.
Do you know if the staff from this website replies to these forum posts? I eventually will need to put together and order list with all the components I need to build this system and it would be great if someone with expertise could help when I get to that point.
Anyway, like I said, I really appreciate your comment and will be exploring the CNC set-up immediately!
Benson usually weighs in on questions.
Heavy loads? You probably need to detail a mechanical system you will use. Lead screws? Rotary tables? Cables and pulleys? Linear rails? Too early to suggest much, until we know more of your needs.
]Send commands at up to 30FPS. /:m] ]Supports multiple servos, motors, relays, and dimmers. /:m] ]SV203 compatible servos and relays. /:m] ]Parallax / Propeller and compatible servos. /:m] ]Use Pololu / Maestro and compatible servos. /:m] ]Use Pololu Jrk with motors. /:m] ]Use PicoPic compatible servos and relays. /:m] ]Use LynxMotion SSC-32 compatible servos and relays. /:m] ]Use K108A Serial Relay Controller. /:m] ]Use parallel port 8-bit and relay output (e.g., K74 LPT Relay). /:m] ]Use DMX devices (requires RAPU v5.0, Velleman, or ENTTEC). /:m] ]Use Board of Chuckie (BoC) DMX servos. /:m] ]Use EnduranceRC 25 Servo Controller servos. /:m] ]Configure custom baud rates for serial ports./:m]
There are RC controlled relays as well which you can connect to the servo controllers above. Regarding the initial trigger, this would need to be verified, and for the servo, we’d need to know some specs like torque / RPM / voltage.
You are right, I guess I have underestimated the power of Servo motors when I said I need to move heavy loads. I have attached some pictures of what a typical application looks like.
I usually don’t need to move stuff heavier than a bottle filled with liquid.
Thank you very much for that!!! I feel like it is such a great start. It does look like something that would let me synchronize all the motors and relays.
I guess if it can be triggered by a 24v signal the software is sold.
I replied to KM6VV[highlight=#000000][highlight=#000000][highlight=#ffffff] about what the motor will handle. I cannot quantify how much torque it needs in specific measurement units. I know that usually most of what I need to do is to tip a bottle of wine or a beer so it pours its contents out. I also know it needs to move fast, for example the bottle of wine needs to go from resting position (approx 45 degrees) to pouring position within 1 or 1.5 second or so. As far as voltage I am not sure, what do they usually operate at?
I guess, just by judging what I have seen other people use the motor could be something like this one?
And Benson, let me know if I am asking too much from you guys, meaning, if you think you could help me identify each component that I can then purchase from your website or if it is a huge undertaking from your part that makes it not worth it.
One thing I am aware of, I know very little when it comes to this type of technology at the moment.
This can all be handled with an RC servo motor controller like the SSC-32U.
Regarding the servos themselves, you’ll need something pretty powerful for a full bottle.
The L42 is pretty powerful, but does not use a standard RC protocol, so would not be compatible with the software above. You might consider: robotshop.com/en/torxis-i018 … =RB-Ins-22 robotshop.com/en/invenscience-en.html
This would require a second USB connection, to allow you to use robotshop.com/en/phidgets-8- … oller.html
Note that the software indicated does not seem to suggest a specific stepper controller, but does allow specific serial commands.
Using the stepper motors will take a bit more time than the rest, unless you can replace them with a different type of actuator?
Thank you again for having pulled aside those pieces for me.
I added them to my list. I was thinking this would be the best motor for me based on its speed, let me know if it is in fact compatible with everything you sourced previously:
“Note that the software indicated does not seem to suggest a specific stepper controller, but does allow specific serial commands. Using the stepper motors will take a bit more time than the rest, unless you can replace them with a different type of actuator?”
Making them work on the software what exactly would that entail?
And to answer your question about possibly using a different type of actuator:
I think I need stepper motors for applications where I something needs to continually turn, like a “display turntable” or a small conveyor belt.
But they are not powerful, at least the ones I own, for applications such as pouring a bottle of wine or even a beer bottle. Often times the bottle of wine is attached to a long U shaped piece of steel that attaches to the motor’s “face” adding weight to the rig and making it impossible for my stepper motors to do the job right. That is why I have been looking into using Servos instead, I heard they could handle that sort of weight.
I also heard of geared stepper motors, and I wonder if they would also get the job done. Any experience with that?
Either way I would need a software to make it all synchronized, I currently do not have a decent way to build a script, I use Arduino and I struggle when I need to change the values of the coding my friend wrote for me.
As far as the software being triggered by a 24V signal coming from the outside, do you think it is possible?
Is your goal to pour a bottle of wine? Sounds neat. Where do you hold the bottle? At it’s center and just rotate it? I’d be inclined to use a stepper (I like steppers). I’ll bet you could do it with 80-15 oz/in stepper. A geared DC motor could also do it. Just rotating at the center of the bottle, the torque requirement shouldn’t be that bad. Do you have a frame set up to rotate the bottle from the center? If so, just add a 12in lever arm, and see what weight at the end of the arm can move the bottle from full, to partially empty, and on to empty. This should suggest a torque.
The motor you last referenced should be more then enough ($$). Or do you need more of a ‘robot arm’ to move the bottle and pour?
a rho-theta arm could move the bottle quite handily. A base rotate (if you need it), with a horizontal arm, and a rotate-able wrist at the end to tip the bottle. Might want to add a gripper to the wrist. Envision your own arm (horizontal and stiff) rotating a bottle to pour.
Most of the times the goal is tipping a bottle of wine, but not always. That is usually the most popular product shot. Some other times for example it is to rig a knife onto the motor and have it slice a vegetable attached to fishing wire that is being released by a gripper from a few feet way. The vegetable flies down on a straight line the motor is triggered and the blade slices the vegetable perfectly in half.
Precision and control of the synchronization are very important. The motor action needs to be repeated hundreds of times without ever changing. And it always needs to know how to go back to the beginning position after the programmed move has been triggered and went from A to B.
That is why unfortunately DC motors cannot be used. I like stepper motors of course because they are very precise but I have been having trouble with two aspects. First my motors are not strong enough to tip a bottle of wine or cut a flying lime in half. Second the software I am using is Arduino, it doesn’t have a friendly interface and because of the way the coding was written (and mainly because I don’t know programming) it doesn’t allow me to expand.
As far as the type rigging you suggested, I agree with you. From the center of the bottle it would be much better. A recurring framing scenario in my work though (filming food commercials) doesn’t allow me to rig from half way down the bottle. The camera is usually framed on the tip of the bottle. If the bottle was rigged from the center it would tip in a way that makes the spout of the bottle move down therefore exiting the frame. The standard rigging is to clench the bottle from the bottom and create a U shaped iron bar. A “U” where the left tip of the you is the bottle’s spout and the right tip of the “U” is the connection to the motor’s shaft. That way when the motor tips the bottle the spout of the wine bottle is exactly in line with the shaft making the tip of the bottle remain fixed in the center of the frame. It is more visually pleasing, the liquid flows out better.
This link will give you a better idea of the work I do, check out minute 2:55
The robot arm sounds good for other applications. How do you usually control the arm? Could the movement of the arm be programmed and synchronized with other motors and solenoids?
Then triggered from an outside 24V signal?
This stuff is complicated to me. Cool but hell for someone like me.
Once you’re using stepper motors or DC servo (not R/C) motors w/ step/direction drivers, you can control them quite well. Think CNC. Repeatable, .001" or finer resolution, anything you want. The CNC-type servo motors and drivers are the solution. If not too heavy, a Stepper works. Encoders get you the feedback you need to ‘close the loop’.
I’m wondering if a 300 oz/in stepper motor couldn’t rotate the bottle w/ the U-shaped rig. Benson’s software can run the step/direction of either stepper motor drivers or DC servo motors.
A robot arm uses either DC servo or stepper motors to move the arm. Same precision! Arms do require a LOT of torque, lever arms and all those calcs.
DC servo motors with encoders and appropriate drivers CAN do exactly what you want. That’s what’s used in bigger CNC lathes and mills.
Sounds like some fun stuff! You might have to look for CNC components to do your job.
I looked into the CNC, it does look promising. My problem is that my knowledge only takes me so far. I think I need to hire someone to design a system because although you guys have helped me narrow down to more specific systems I still have no clue about how to actually put them together. For me it is like learning a new language, I wonder if I should just commission this type of work to someone who does it everyday and could artfully put together something in a short amount of time.
I will take with me what I’ve learned from you when I speak to somebody about building a motion control system.
You’re help has been priceless, thank you so much.
Yeah, there is a difference between R/C model construction, and commercial CNC design and implementation.
There is a LOT of knowledge required to design/build complex electro-mechanical systems, especially when you add in the computer controllers and programming.
