can we use Bot Board & BASIC Atom / Pro for control the Dc motors?
if what you mean by “for control the Dc motors?” is supplying a control signal to the dc motor controller then sure.
if you are asking if you can plug the dc motors directly into the bot board then the answer is no.
dc motors can draw from hundreds of mA to several amperes. the bot board is, at the simplest level, a breakout board for the atom module. thus all the signals coming into or out of it are TTL level or analog (ie. the a/d inputs). at most the TTL signals can deliver a few tens of mA.
are you still missing the idea that there is a small circuit board in a hobby servo that interfaces the TTL level signal from a bot board (or ssc-32) to the dc motor inside the servo?
at the simplest level you need an H-bridge (look it up if you need to) between the dc motor and “something” controlling it. For a small dc motor that only draws an ampere or two at most an L297 based h-bridge should do the job and there are numerous boards based upon it available. Now whether the bot bosrd+atom pro module can provide the signals to directly drive an h-bridge or not… I’m not certain but I sort of doubt it. Usually one end of an H-bridge is driven with a PWM of a few KHz while the other end is used to control direction. I don’t recall offhand if there is a hardware PWM output available from the atom pro or not but the frequency required it isn’t something that lends itself well to a bit-banged PWM output. It may be an L297 provides the PWM frequency… there are some controllers that do… but I don’t remember off the top of my head.
hi
I have 3 axis Industrial robot .I want to buy these 3 sets of the components below to control my robot,
se.farnell.com/maxon-motors/2505 … dp/4158921
se.farnell.com/maxon-motors/1375 … dp/4158740
and encoder.
is there here to know how can i contol these component by PC. i mean how can synchronize these component to ghether. Is there any other device that do i need?
Is there any device to connect 3 Dc motor derive to computer?
regards
I’ve not set and studied this in any detail yet but I do notice you have paired a 50W controller with a 70W motor. o.O
Also the type of signal input needed for the motor controller is more suited to an industrial PLC (programmable logic controller) than the basic atom. to use an atom you will need to wire up an external digital to analog converter to produce the required -10 to 10 volt control range. it is possible there is information on the basic micro website or in their forums about this sort of thing if others are using their products in this manner.
I don’t see anything that gives your controller, basic atom or a PLC or a PC via a DAQ interface, the encoder signals. the selected motor has a max rpm of roughly 6700, /60 to get 112 rps. the max encoder frequency to the selected motor controller is 100khz so 100e3 / 112 = 892 which sets the max encoder resolution you can use. I seriously doubt the basic atom or even some PLC can handle that kind of frequency rate so you’ll need to choose an encoder with much less pulses per rotation. controlling this directly from a PC will need something like a DAQ from NI or any number of clone manufacturers. Whatever software you plan to use on the PC, if it is a commercial package, may have a list of “supported” DAQ peripherals that you should examine before selecting something.
3 axis is pretty common for CNC table. Many of the home-built CNC tables are controlled with stepper motors but there may be existing 3-axis controllers for DC motors available. Perhaps one of the guys on the forum that know a bit more about the hows and whats of building your own CNC can throw out some suggestions for where to look for solutions.
thanks for your response,
My question is that if I buy 3 motor and 3 controller to control the motors, how can I synchronize the motors??. I mean how can control 3 motor together and at the same time??( i want to give the command for setting the position and velocity to follow a trajectory).
regards
As Eddie has said, you don’t have all the parts, I think. the servo amplifiers needs to be driven from some sort of PID controller. Often that controller is or requires a custom controller board in the PC or industrial computer. The Software driving the controller sends positions or velocities that are “in sync” and controlled such that the axis cooperate and get the controlled axis to there target in coincidence. That’s called coordinated movement.
Forget the controller, go look up Gecko
And read up on their servo controller modules.
Look up SherlineCNC (below), Which is for the Sherline mill and lathe. Is that similar to what you’re doing? You haven’t said.
Look up CCED
groups.yahoo.com/group/CAD_CAM_EDM_DRO
List which is for CAD and CAM on most any machine.
Look up The Turbocnc list
tech.groups.yahoo.com/group/turbocnc/
Which is free software.
EMC would be another good controller program (free) that can control most anything.
Basically, you are building a CNC system. Lots to learn!
HTH
So what are you building?
Alan KM6VV
do you think this kind of controller can be useful?
what’s your idea about that?
robotshop.ca/roboteq-ax1500- … ler-1.html
thanks
Did you look up any of the references I posted?
This is a hobby motor driver.
You want a servo motor controller. You’ll also have to add an encoder to the motror. This motor driver does not take encoder inputs.
R/C and serial inputs are generally not fast enough for CNC or motion control applications. for analog input, you’d still need the “controller” portion of the motion system.
You still have not told us your application.
Alan KM6VV
For more information to help me
I am student of mechanical Engineering in Linkoping University Sweden. Now I do my master thesis in robotic.
I want to make a small industrial robot with 7 axes.
At the first part I start with 3 axis industrial robot. I design my robot in CATIA and print it by 3D printer. We work with DYMOLA software (it is a design tools) also to do a inverse kinematic for our robot and find parameters of a trajectory (position and velocity), (( Example for trajectory is to write a word like ‘‘LIU’’)).
Our goal is that the 3 axis robot does the trajectory which is come from DYMOLA. At this phase, I start to work with servo motor SSC_32 controller. But my supervisor prefers that we close as much as possible to real industrial robot. So we decided to start with DC motor and DC controller. I am not an Electrical or computer engineering so I haven’t a deep knowledge in electronic. I want to help me to find some suitable eclectic device for our project. I know that I need these part (if I need more component please write for me!!)
DC motor
Set of gear reduction
Encoder
DC motor controller
Power supply(like battery)
I can find DC motor, gear and encoder easily but the problem is that I cant find the suitable dc controller .because I have 3 motor and encoder I need a controller with 3 input port for motor and encoder other wise I don’t know how can I synchronize these 3 motor and 3 controller together to do my trajectory. I also want to control the motors by PC, I mean I want to connect the controller to PC and send the command from PC to controller, but I can’t find a controller with connection to PC. Honestly I don’t know any other solutions for that maybe there is a solution.
For motor, gear and encoder I decided to buy this
transmotec.com/dc-motors/pla … eries.aspx
But I still have problem for finding controller, please help me.
Thanks in advance
I’m not an engineer nor am I a student, but if you want to get precision control from your motors, you will need a stepper motor or a servo motor, DC motors are great for wheeled robots but horrible for precision control. Servo motors are higher resolution than steppers and are stronger as well, so servo motors are the best choice.
If you still want to go the DC rout, then I don’t know what to tell you other than you will need to design and build your own controller or keep searching the web for one that will work with the motors you posted a link to.
I suggest you make a project web page with the design specifications for the robot you are building. Provide sketches of the robot so everyone will have the same concept of what what it will be. This will save time and effort posting piece by piece bits of information on the project and probably generate better suggestions for what you want to do.
I have built 4-axis mill, lathe and PCB router CNC machines. Look at the references I posted.
the Gecko controllers (either stepper or servo) will give you closed loop (servos), can be controlled from a PC running Turbocnc (another link) and will automatically do the coordinated motion (your trajectories).
For “gears”, it’s better to use timing belt pulleys. An approximately 3:1 gearing for steppers will work quite well with small machines.
The CCED list or my SherlineCNC list is a good place to ask questions like this. Members of those lists are quite knowledgeable, and will be quite helpful. And when asked, will provide plenty of explanations and additional choices.
Your motor is rather small. go to something with a 1/4" shaft (or bigger) for small CNC machines. Use the timing belts.
Unless you are building a model of a CNC machine, forget about using R/C servos to run it.
Kindly follow up on the references I’ve posted.
Alan KM6VV