Help in creating a system to control a stepper motor + drive manually, to move a machine on rails linearly

Thread Starter

SS23

Joined Dec 12, 2019
22
Initially, for manual mode, you could configure your driver for ‘run’ mode, then add momentary push buttons to actuate it.
Using Labview, you would need a translator to output/input the drive signals. What do you have for Labview I/O?
Hey @GetDeviceInfo I will look up for your suggested way. In Labview we have a CompactDAQ chassis with some DAQ cards to read Analog and Digital Inputs and outputs. I think that should cover up almost all the parts that I wish to connect.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
Hey everyone! I have found a microcontroller to generate the signals manually to move the motor + drive. Do you think I could connect this to a hand-held switch for MOVEMENT and DIRECTION functions? And about its reliability? I didn't find something as easily installable.
Just to say again the motor and drive I am using are:
1. Motor: SANMOTION SM 2861-5055 3,6 Nm
2. Drive: RTA A-NDC Series 6A Peak current
3. Link to the Signal Generator (No PDF :| )https://hobbycomponents.com/motor-drivers/537-pulse-pwm-generator-for-stepper-motor-drivers
Waiting for your suggestions and feedback!
 

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shortbus

Joined Sep 30, 2009
8,470
I know I'm sounding like a troll but your making this so much harder on yourself. Without a precise repeatable location for each engine, motor or what ever you are testing, how is this going to make things easier? And why use a microcontroller? Which you didn't link too.

If your calling the pulse generator a microcontroller, it's not. It won't easily do what you want, those are more for just making steps not making precise movements of a stepper motor, to get your dyno aligned. I am doubting you can even switch it on and off fast enough to move a small distance say like a millimeter, probably not even a centimeter. For precise movement you need one of the rotary signal generators like I linked to in post #5, something like this there are many available ones to choose from. https://www.amazon.com/Rotary-Manual-Generator-Handwheel-100PPR/dp/B00ZO6UOCO One of those will take the place of your PWM module. It will allow you to do both rapid and precise movement, depending on how fast you turn the hand wheel.

But all of this could be made much easier on you or the people using the dyno by taking a real world proven approach to how things are done in real life settings. I'm beginning to think this whole thing is some kind of school project. I can't imagine a real engineer doing it so randomly.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
I know I'm sounding like a troll but your making this so much harder on yourself. Without a precise repeatable location for each engine, motor or what ever you are testing, how is this going to make things easier? And why use a microcontroller? Which you didn't link too.

If your calling the pulse generator a microcontroller, it's not. It won't easily do what you want, those are more for just making steps not making precise movements of a stepper motor, to get your dyno aligned. I am doubting you can even switch it on and off fast enough to move a small distance say like a millimeter, probably not even a centimeter. For precise movement you need one of the rotary signal generators like I linked to in post #5, something like this there are many available ones to choose from. https://www.amazon.com/Rotary-Manual-Generator-Handwheel-100PPR/dp/B00ZO6UOCO One of those will take the place of your PWM module. It will allow you to do both rapid and precise movement, depending on how fast you turn the hand wheel.

But all of this could be made much easier on you or the people using the dyno by taking a real world proven approach to how things are done in real life settings. I'm beginning to think this whole thing is some kind of school project. I can't imagine a real engineer doing it so randomly.
I get why you're saying that but in the laboratory where I work we have some old equipment that needs to be automatised or the least mechanised. As, me personally, I just work on the test stand for my own project and have to use it the most, they asked me if I could suggest something to make it automated for future use. As, I haven't done these sort of projects before, I am really starting from scratch and hence these random questions and choices.

As most of my findings have been from the online searches and readings, I came across this pulse generator. I have had some basic training on LabView , and we plan to also control this dyno stand via LabView in future, I suggested it. Of course, I don't mind you raising these questions but being completely new in this, I might have some wrong choicing. Hence, the point of me coming up with the queries here!
 

MrChips

Joined Oct 2, 2009
23,232
I would suggest that you start from square one.
Tell us what you are trying to achieve from the big picture.
Tell us what equipment you have, that you are now using, and that you hope to be used in the final setup.
Ignore the need for a stepper motor controller for now and let's start with a fresh view.

I call this Systems Design Engineering.
 

Reloadron

Joined Jan 15, 2015
5,916
All of this sounds eerily familiar. You may want to Google "linear scales with digital readout" including a readout you can interface with. Driving a lead screw with a geared stepper motor and using a linear scale you will know where your table is. This is exactly what MrChips called it. System design engineering. You list your objectives and design a system to do what you want done. You can make it as simple or complex as you want. You need well defined parameters.

Ron
 

Lo_volt

Joined Apr 3, 2014
161
MrChips gives some good advice. Step back and look at the whole picture. You have decided on a stepper motor but I don't think that's the best choice for you. Personally, I'd look at a servo motor and I'll ask you to google "nema 34 servo motor". The results for me came up with a few viable options. I'll also suggest that you review servo motors in general and look at one or more that may look promising to you. Most of them come with basic software that will allow simple positioning with a jog option to tweak your payload (the dyno) into position.

Back to looking at the whole picture, once you've done some research on what servo motors vs. steppers can do, I think you'll be better prepared to decide which option you want to go with.

Look around as well for local vendors who can put together a package to fit your specs. They typically have field or applications engineers that can provide information and offer suggestions as to what options will fit your needs. They will also be able to offer options such as power line filters, safety features, etc. that may be appropriate.
 

LesJones

Joined Jan 8, 2017
3,132
As you will have a number of final stopping positions to mate up with different devices under test do you want to enter a position (In mm for example.) Or do you want to create a database with an entry for each device type so that rather then entering a position you just select a device type from a table. (So that you do not have to keep a list on paper of a position corresponding to that device type.) You will also have to consider how you will enter this information. So you will need some kind of display and keypad. Will this be on the machine or entered and displayed via a PC or tablet etc. ? Also consider how many device types there will be. (Just a few or tens of thousands.) Also consider safety devices to prevent the machine moving while someone is working on coupling up the device under test. It is much better to consider all these things at the start rather than having to keep going back to change the design.

Les.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
Thank you for the humble feedback once again. I took some time and thought of the system as a whole with what and how it should work. Hence, I try to describe the system more clearly.

OVERALL AIM: To move a dyno on rails by two possible ways, MANUALLY VIA SWITCHES on WALL and THROUGH PC VIA LABVIEW program.

MANUAL WAY: I want to install a few switches on the wall near dyno to move the (Motor+drive), that will eventually move the dyno. A switch for Movement and another to choose direction should be enough. Holding the switch, means dyno moves.

PC WAY: There needs to be a way that the dyno could also be moved by sending pulses to the drive of stepper via LabView. The hardware (DATA ACQUISITION CARDS) and software (LabVIEW) are already available.

CHOICE BETWEEN THE TWO: The idea is that there should be a switch that can be manually operated, to allow choosing one of the two ways of control. This gives different ways to operate the dyno based on the test being done. Simple test: MANUAL, a longer/complex run: CONTROL VIA PC.

PARTS OF THE SYSTEM (Available/buy)
  • STEPPER MOTOR-available + DRIVE-buy ( I am aware many of you suggest a servo motor but there seems to be a spare stepper motor lying in the workplace. Some skipped steps will be acceptable. I reconfirmed that with the others)

Config of the motor: 2 Nm to 6 Nm Torque. (Tested by measuring the torque that the gearbox can take. Maximum was 6 Nm at 1800 RPM. The available spare motor fits the range)
Its a SANMOTION 5,6 Nm NEMA 34 Stepper Motor, 6 A Bipolar. With a 48-75V DC input voltage requirement.

Drive for the motor: RTA NDC 96 (Compared its compatibility with the stepper-feasible)


  • Inductive sensors: 2 - buy (Needed at both ends of the test stand to prevent overrunning of the dyno to the edge of rails)

  • Wall mounted switch to choose b/w MANUAL and PC modes- buy

  • Wall mounted box with switches for DIRECTION and MOVEMENT - buy

  • LabView and hardware to generate pulses via PC- available


THINGS STILL TO DO/FIND-OUT:
  • A device or a controller that is compatible with both ways of controls. To allow sending pulses to the drive of the motor to move the dyno.
  • Overall electric circuit for connecting various parts. (Working on electric connections for the already available parts).

As we are starting fresh with the approach, I haven't included the suggestions for solution, some of you suggested above. Being new with working on a practical project that involves so many constraints, I will surely make errors or wrong assumptions, hence your support is really important. I have taken up this challenge and wish to complete it!

Picture2.jpg
 

Reloadron

Joined Jan 15, 2015
5,916
Years ago I worked with a system similar to your drawing. It was for a clad welding system but same idea. We used Thompson Pillow Blocks for the table. Stepper motor was an Anaheim Automation 42N112S-CB8 Stepper Motor which is a pretty high torque motor and we drove the motor into a 50:1 gear box driving a lead screw. Used the DPD72001 Anaheim Automation controller. The motor and controller allowed 1/2 step control which was more than accurate enough. The software was pretty much VB 6.0 and the interface modules were all Opto 22 stuff. Position feedback used a simple linear position indicator like those used on large mill and drill systems for position readout. You could likely also use a string pot depending on your positional needs. Different products just used different programs selected from a drop down combo box. You could have auto or manual control and manual control was no more than a few bypass switches and a few V to F modules to drive the stepper motor control. You just include MAN / AUTO in your design as you start it out on paper. Rough guess it was maybe 2006 or 2007 we designed and used this. When I retired in 2013 it was still running fine. Today we likely would have used LabVIEW for the software and the same hardware.

I am merely mentioning what we used in an old design. You will want to know the torque of your choice of motor. How you choose to go about it is your design.

Ron
 
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GetDeviceInfo

Joined Jun 7, 2009
1,844
Thank you for the humble feedback once again. I took some time and thought of the system as a whole with what and how it should work. Hence, I try to describe the system more clearly.

OVERALL AIM: To move a dyno on rails by two possible ways, MANUALLY VIA SWITCHES on WALL and THROUGH PC VIA LABVIEW program.

MANUAL WAY: I want to install a few switches on the wall near dyno to move the (Motor+drive), that will eventually move the dyno. A switch for Movement and another to choose direction should be enough. Holding the switch, means dyno moves.

PC WAY: There needs to be a way that the dyno could also be moved by sending pulses to the drive of stepper via LabView. The hardware (DATA ACQUISITION CARDS) and software (LabVIEW) are already available.

CHOICE BETWEEN THE TWO: The idea is that there should be a switch that can be manually operated, to allow choosing one of the two ways of control. This gives different ways to operate the dyno based on the test being done. Simple test: MANUAL, a longer/complex run: CONTROL VIA PC.

PARTS OF THE SYSTEM (Available/buy)
  • STEPPER MOTOR-available + DRIVE-buy ( I am aware many of you suggest a servo motor but there seems to be a spare stepper motor lying in the workplace. Some skipped steps will be acceptable. I reconfirmed that with the others)

Config of the motor: 2 Nm to 6 Nm Torque. (Tested by measuring the torque that the gearbox can take. Maximum was 6 Nm at 1800 RPM. The available spare motor fits the range)
Its a SANMOTION 5,6 Nm NEMA 34 Stepper Motor, 6 A Bipolar. With a 48-75V DC input voltage requirement.

Drive for the motor: RTA NDC 96 (Compared its compatibility with the stepper-feasible)


  • Inductive sensors: 2 - buy (Needed at both ends of the test stand to prevent overrunning of the dyno to the edge of rails)

  • Wall mounted switch to choose b/w MANUAL and PC modes- buy

  • Wall mounted box with switches for DIRECTION and MOVEMENT - buy

  • LabView and hardware to generate pulses via PC- available


THINGS STILL TO DO/FIND-OUT:
  • A device or a controller that is compatible with both ways of controls. To allow sending pulses to the drive of the motor to move the dyno.
  • Overall electric circuit for connecting various parts. (Working on electric connections for the already available parts).

As we are starting fresh with the approach, I haven't included the suggestions for solution, some of you suggested above. Being new with working on a practical project that involves so many constraints, I will surely make errors or wrong assumptions, hence your support is really important. I have taken up this challenge and wish to complete it!

View attachment 235185
Maybe give us a step by step procedure as to how they currently dock the dyno. Parts of this doesn’t sound practical.
 

LesJones

Joined Jan 8, 2017
3,132
As you plan to use Labview I will not be able to help with that part as I have never used Labview and have no idea how it communicates from the PC to external hardware. (I.E USB, serial link, ethernet of some proprietary card that plugs into the PC backplane.).

Les.
 

MisterBill2

Joined Jan 23, 2018
8,446
Labview iis very capable of doing a whole lot. What I did not see on that quite-good drawing is any position feedback at all, other than operator control and observation. For automatic control of almost every kind, feedback is needed, either limit switches or proportional signals, analog or digital. For an engine dyno of some kind, if there is not backlash in the leadscrew system that adjusts position, then a simple shaft encoder on the leadscrew can be adequate. If there is backlash or play in the linkage then actual position sensing would be required. That gets a bit more complicated. The accuracy and resolution requirements also have a large effect on how position is controlled. For one automotive engine test line actual hard stops were used, with hydraulic cylinders providing the motion. Not easily flexible, but for one model at a time, adequate.
 

shortbus

Joined Sep 30, 2009
8,470
Parts of this doesn’t sound practical.
For automatic control of almost every kind, feedback is needed, either limit switches
This is what I've been saying right along. There should be a "station" or two if like he is saying the dyno is used for two types of measuring. Can you imagine how hard it would be to do the same thing over and over again with a ~3600 pound object that wasn't in the same place each time you want to access it? Where testing or making something with a machine, which this is, and always moving the work area is just making a job much harder than it needs to be. And then trying to do it using a micro controller that doesn't even know where to move to or from??
 

Lo_volt

Joined Apr 3, 2014
161
@MisterBill2 and shortbus He's got "inductive sensors" that appear to be limit sensors. One thing he doesn't have is a home sensor. This sensor will provide a home position that is not at the end of travel and can be used to find a repeatable position reference.

A couple more things to think about:
-An E-stop switch, typically a big red mushroom switch to remove power from the motor should something go wrong. Your drive likely has an input for such a switch.
-You are using a lead screw. If there's a chance that your payload can trap a person or thing then even if the power is removed, your lead screw will have to be manually backed off to release the trapped person or thing. Look to see if it's possible for the screw to be hand cranked or for the payload to be quickly disconnected from the lead screw in the case of such an entrapment.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
Maybe give us a step by step procedure as to how they currently dock the dyno. Parts of this doesn’t sound practical.
CURRENT MOVEMENT METHOD:
At present, as we await a mechanized setup to control the movement, for now there is a temporary way to move it. At the output shaft of the gearbox is attached a manual hand wrench, which when rotated manually allows leadscrew to move and hence the payload as well. But as the gearbox itself has a 4:1 ratio its very slow manually to provide movement.

Also due to the temporary hand wrench based movement, we try to move other test stands more than this one when a test is needed to be done. And the persons testing are present next to the dyno for the precision for movement. So it takes two persons to see the correct positioning of the dyno on rails. One rotates the wrench on gearbox and one looks for the position.

I am more concerned with finding a device that could allow MANUAL as well as LabView based movement or control of the Stepper + drive. @MisterBill2 We plan, once the movement part is taken care, to also install a wire-based position sensor. They are used in other test stands, so we could find a spare. I could even enquire tomorrow what we have, but for now, I really want to get this moving with a switch and labview.

@Lo_volt Yes, you're right, I intend to use inductive sensors in place of limit switch. I think they are cheaper and simpler. We also have them in-house in the store. Yes an E-switch is important. I will add it to override everything. I still haven't finalized the electric scheme.
Well, as the dyno is on the stand and most attachments to it are accessible without being on the test stand physically, I think a person couldn't fit in between or around it. I will still have a look if there could be such a possibility.
 

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GetDeviceInfo

Joined Jun 7, 2009
1,844
I asked that last question to establish that a technician is overseeing the positioning of equipment. Out of experience, this is necessary to accommodate for the infinite variability in any given situation. In a case like this, a remote control, in the hands of that technician, is likely your best option. Unless you can guarantee the precision of components, unsupervised automation is unwarranted.
I understand where Labview comes in, because you have it. I’ve used it to construct operator interfaces, only because it was already a component of the system, but it wouldn’t be my choice otherwise, for that task.
Sounds to me that you already have the hardware, so be it. Set your driver to run mode, tether a push button operator so that the technician can drive the sled while making the connection. Not as glamorous as pick and place robots, but for the application, practical.
 

shortbus

Joined Sep 30, 2009
8,470
He's got "inductive sensors" that appear to be limit sensors. One thing he doesn't have is a home sensor.
What good is a home sensor when the device under test is not in the same place every time?? And the limit switches are to keep the sled from going off the rails or jamming the lead screw, or that is what he said earlier in the thread. Any type of machine I've ever seen has a set place for a set part of the operation. he is moving the device under test to where ever he wants. And then trying to match up the sled/dyno to that position. So if he tests, lets say 10 engines/motors a day, he has to find the location that many times.

Now we don't know how the motor/engine connects to the dyno, but any dyno I've ever seen has to align up withing a few thousands of an inch. A couple of guys I used to work with enter something called the "Engine Masters Contest", to see who can make the most horsepower folowing a certain set of rules. There they have a dyno that is fixed, and each engine isput on a stand, the stands are made to wheel up to the dyno and the center of the crankshaft is preset to line up to the center of the dyno input. They test many engines a day with only hooking up water, electric and exhaust. Each stand fits only one way into the dyno.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
Now we don't know how the motor/engine connects to the dyno, but any dyno I've ever seen has to align up withing a few thousands of an inch.
I completely get your concern with regards to the connections. But as we have other stands that need to also be aligned so I think there is a margin with regards to the accuracy. And it depends on the type of tests. Sometimes its just a simple gearbox connected to the dyno and then screwed to the central shaft of dyno and the gearbox is mounted on a platform fixated to the workshop floor. About our workshop floor, it has those square accents to allow for fixation of such mounts around the test stand and has the sleeves to move the mounts.
 

Thread Starter

SS23

Joined Dec 12, 2019
22
I asked that last question to establish that a technician is overseeing the positioning of equipment. In a case like this, a remote control, in the hands of that technician, is likely your best option.
Set your driver to run mode, tether a push button operator so that the technician can drive the sled while making the connection.
Yes, the person/technician doing the tests makes sure the position before initiating the test. This automation aims to make it easier and will eliminate the need of few persons to safeguard the movement. And for those quick adjustments the MANUAL mode should be really helpful. Also, with LabView, we plan firstly, to remotely control the movement and in future, we could sync this test stand to others for automated positioning in larger test scenarios.

But, my question is that can I make a switch to choose whether to move via a push button (MANUALLY) or via LabView? Because these both suggested ways of control would be connected to a single stepper drive. And would the stepper drive allow that? Shouldn't I need a pulse generator for moving it through a switch? Some guys above suggested a pulse generator wheel but that wouldn't be operable by a switch then, isn't it? The drive I plan to install: RTA A-NDC 96, has these connection options in the pdf below.
P.S: The stepper motor is available, we need to buy a drive for it though. Hence, the queries.
 

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