Motor for conveyor [SOLVED]

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
I've seen a youtube video in which the barcode is printed on the package above the conveyor Belt

Video


I am curious to know the following

1) Which type of motor is used to drive the conveyor belt?

2) Which motor is used to drive the belt single phase or three phase motor?

Both the questions have arisen by seeing the machine in the video
 
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LesJones

Joined Jan 8, 2017
3,661
First point is the video is showing the printing of a QR code not a bar code. Rather than asking what type of motor is used video you need to think about what is required to print the bar code. (I will just talk about bar codes as these are simpler to print than QR codes.) I assume that inkjet type printing is being used. If the stripes of the barcode are at right angles to the axis if the conveyor then there thickness will depend on how far the conveyor moves in the time that the inkjet is actuated. There are two ways to control the width of a stripe. One is to accurately control the speed of the conveyor and then the with is a function of how long the inkjet is actuated. The other is have an encoder on the conveyor that gives one pulse for a fixed distance that the conveyor has moved. (This would need to be a very small distance so there was a number of pulses for the thinnest stripe of the bar code.) The inkjet nozzle would then be actuated for a number of these pulses depending on the on the thickness of that line. using this method the speed of the belt would not need to be accurately controlled. Which of these two methods was chosen would be decided on if the conveyor speed needed to be changed due to the production process or the cost tradeoff of having to accurately control the speed against the cost of the inkjet control. Each system has to be designed using ALL the facts about the system.

Les.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Rather than asking what type of motor is used video you need to think about what is required to print the bar code.
Les.
I asked about the motor because I think the starting point of this machine is the motor that drives the conveyor belt. Obviously the machine has more function but I don't think this is the right time for me to discuss it so I was just focusing on the motor at this time.


So my specific question is, Can 1HP single phase dc motor used in this kind of machine?
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Yes, if it is suitable.
And how to know whether it is suitable or not?

Is this the only way to do this, buy the motor first and power it up and see if it can drive the conveyor?

If the conveyor belt doesn't run, isn't it a waste of money?

I found that a VFD is needed to control the speed of motor
 

BobTPH

Joined Jun 5, 2013
4,320
And how to know whether it is suitable or not?

Is this the only way to do this, buy the motor first and power it up and see if it can drive the conveyor?
No, it is called engineering. You calculate the power and torque needed, then choose an appropriate motor.
If the conveyor belt doesn't run, isn't it a waste of money?
That is why you don't do engineering by random guess.
I found that a VFD is needed to control the speed of motor
Not for a DC motor. Try again.

Bob
 

ericgibbs

Joined Jan 29, 2010
14,728
And how to know whether it is suitable or not?
Hi P,
Your questions and requests for information are far too vague and open-ended.

You must be more specific with your questions.

It is unreasonable to expect your fellow members having to search for and post information that already exists on the web and that can be easily found by you, by doing a word/phrase a search.

E
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Hi P,
Your questions and requests for information are far too vague and open-ended.

You must be more specific with your questions.

It is unreasonable to expect your fellow members having to search for and post information that already exists on the web and that can be easily found by you, by doing a word/phrase a search.
I try my best to find answers to my questions. I do research before asking and when I am confused or need clarification only then I post questions
 

ericgibbs

Joined Jan 29, 2010
14,728
I am confused or need clarification only then I post questions
Hi P,
With due respect, you are confused because you are not thinking through the questions you are asking.

For example: So my specific question is, Can 1HP single phase dc motor used in this kind of machine?

How do consider this question to be specific or answerable.?

May I also ask what are you doing with all this information across such a broad spectrum of technology.?

E
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
May I also ask what are you doing with all this information across such a broad spectrum of technology.?
I'm trying to learn how to solve a real problem. I try to find solution for whatever real problem I see.

i can't make the machine i posted in the video because i don't have that much budget. But it does not cost money to think how this machine is made, that's why I thought to understand how it is made. I just focused on how to design a only one part of the machine which is the conveyor controlling system.

Bob has given some hints in post #7, I'm just searching for how it fits into my requirement.
 

Marley

Joined Apr 4, 2016
450
Often a VFD (Variable Frequency Drive) is used to drive a small induction motor in this type of application so that the speed of the belt can be easily adjusted. Could be single or 3-phase. Usually single phase for small motors.
The motor power depends on the length of the belt, whether the belt is level or required to lift the items, the amount of friction in the system. For small and level and small cards as in your video, about 0.5kW would be common.
The ink-jet printer will have an optical sensor that detects the leading edge of the card. Settings in the printer will add a delay before the printing starts (margin from the front edge) and the speed of the card (the overall length of the QR and text).
 

strantor

Joined Oct 3, 2010
5,753
First point is the video is showing the printing of a QR code not a bar code. Rather than asking what type of motor is used video you need to think about what is required to print the bar code. (I will just talk about bar codes as these are simpler to print than QR codes.) I assume that inkjet type printing is being used. If the stripes of the barcode are at right angles to the axis if the conveyor then there thickness will depend on how far the conveyor moves in the time that the inkjet is actuated. There are two ways to control the width of a stripe. One is to accurately control the speed of the conveyor and then the with is a function of how long the inkjet is actuated. The other is have an encoder on the conveyor that gives one pulse for a fixed distance that the conveyor has moved. (This would need to be a very small distance so there was a number of pulses for the thinnest stripe of the bar code.) The inkjet nozzle would then be actuated for a number of these pulses depending on the on the thickness of that line. using this method the speed of the belt would not need to be accurately controlled. Which of these two methods was chosen would be decided on if the conveyor speed needed to be changed due to the production process or the cost tradeoff of having to accurately control the speed against the cost of the inkjet control. Each system has to be designed using ALL the facts about the system.

Les.
I have experience with this technology in the wire/cable industry (printing on cable jackets in motion) and also the logistics industry (printing on bags/boxes in motion). Yes, it is ink jet. All of the machines I have encountered had optional encoder feedback, but it is rarely needed. I have never seen seen the encoder option used. Wire/cable applications usually have an "encoder" wheel riding on the cable but this is usually not a true quadrature encoder but a 1PPR rotary Reed switch which counts off feet of blank space between cable markings. The actual timing of the printout is open loop. You input line speed in the printer and make sure that what you input matches reality. If in reality you are running slower than what you input, your prints will be scrunched up. If faster, stretched out. Usually these things run a fixed speed so there is no issue. Sometimes an analog output from a drive (capstan drive for wire, belt drive for conveyor) is connected to the printer to represent actual line speed so the printer can compensate. I can't think of an application where this would be insufficient and an encoder would be required. Maybe if the target is prone to frequent uncontrolled movement/ slippage? There are some tricks for better results; for example if printing barcodes, print them perpendicular to the axis of travel so that any shrinkage/ expansion will make the barcode taller/shorter (but still readable) instead of variable in length.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
Often a VFD (Variable Frequency Drive) is used to drive a small induction motor in this type of application so that the speed of the belt can be easily adjusted. Could be single or 3-phase. Usually single phase for small motors.
The motor power depends on the length of the belt, whether the belt is level or required to lift the items, the amount of friction in the system. For small and level and small cards as in your video, about 0.5kW would be common.
The ink-jet printer will have an optical sensor that detects the leading edge of the card. Settings in the printer will add a delay before the printing starts (margin from the front edge) and the speed of the card (the overall length of the QR and text).
Have you build this type of project or worked on similar projects? If yes can you explain what was the main purpose?
 

GetDeviceInfo

Joined Jun 7, 2009
1,965
It would be common in my experience, that the motor would be a 3ph induction driven by a VFD, with the printer being driven from a high res encoder. As a simple conveyor, the supplier may offer various configurations to attract a broader customer base.
 

shortbus

Joined Sep 30, 2009
9,073
Any conveyor I've ever had anything to do with doesn't just have a motor, they also use a reduction gear box. Just a motor alone usually can't be slowed down enough to run a conveyor at a slow enough speed, and the gearbox also allows a smaller horsepower motor to be used.
 

shortbus

Joined Sep 30, 2009
9,073
I have experience with this technology in the wire/cable industry (printing on cable jackets in motion)
I also have had experience in this. But we did it differently. We used etched/engraved print wheels and ink to print the information on our cables and spark plug wire. while not the company that made ours, they were made like these - http://www.rsdtechnik.de/index.php/marking-and-printing/printing-wheels
The wheels ran in a pan of paint/ink and had a wax wiper to remove all but what was trapped in the engraved surface. The wire moving past the print wheel also turned the wheel.
 

Thread Starter

Pushkar1

Joined Apr 5, 2021
416
I have never seen seen the encoder option used.
I have experience with this technology in the wire/cable industry (printing on cable jackets in motion) and also the logistics industry (printing on bags/boxes in motion). Yes, it is ink jet. All of the machines I have encountered had optional encoder feedback, but it is rarely needed. I have never seen seen the encoder option used. Wire/cable applications usually have an "encoder" wheel riding on the cable but this is usually not a true quadrature encoder but a 1PPR rotary Reed switch which counts off feet of blank space between cable markings. The actual timing of the printout is open loop. You input line speed in the printer and make sure that what you input matches reality. If in reality you are running slower than what you input, your prints will be scrunched up. If faster, stretched out. Usually these things run a fixed speed so there is no issue. Sometimes an analog output from a drive (capstan drive for wire, belt drive for conveyor) is connected to the printer to represent actual line speed so the printer can compensate. I can't think of an application where this would be insufficient and an encoder would be required. Maybe if the target is prone to frequent uncontrolled movement/ slippage? There are some tricks for better results; for example if printing barcodes, print them perpendicular to the axis of travel so that any shrinkage/ expansion will make the barcode taller/shorter (but still readable) instead of variable in length.
I don't understand following points

1) how the printer will print if the belt speed is adjustable.

2) Does each label have to be the same size?

3) Is the encoder used to track the position of the label

4) What should be the gap between the two labels
 
Last edited:

LesJones

Joined Jan 8, 2017
3,661
stantor has answered question 1. " Sometimes an analog output from a drive (capstan drive for wire, belt drive for conveyor) is connected to the printer to represent actual line speed so the printer can compensate. "
Questions 2 and 4 will depend on the required specification from the customer.
Question 3 If an encoder is used it does not keep track of the position of the labels.
I have NOT worked on conveyors or label printers so I am just thinking about what I think is required to make the system work.

Les.
 

MaxHeadRoom

Joined Jul 18, 2013
24,273
I have had experience with a similar machines that probably works in the same principle, One is called a flying shear.
Where material such as fabric or sheet steel etc is fed continuously at high speed and needs to be cut to a specific length. The material is cut on the fly without the need for the material to stop.
Once the shear has operated it accelerates back and then resumes travel with the next sheet shear point is seen.
A carriage carrying the shear must be accelerated to meet the speed of the feed material before the cut occurs. Incremental encoders are used on the traveling parts to keep each in step.
The others are not so dramatic but similar in operation and are used to stamp the weight on pre-packaged foods such as cheeses, meats, fish etc, where the weight is not known ahead of time.
The conveyor motor in such a machine just requires a constant, uncontrolled RPM as the synchronizing is done with encoders on the crucial moving parts.

http://docplayer.net/44091851-Galil-motioncode-solution-computer-controlled-flying-shear.html
 
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