Do you have all the hardware in place at least?
Max.

 

Do you have all the hardware in place at least?
Max.

I have no hardware except for the arduino. Which I'd happily ditch. Really I don't know what to buy. Need to know sizes etc so I can finalize mounting holes etc

 

I meant the mechanical Hardware, if this is a prototype, if the mechanics are in place as in post #21 then the motors can be sized to suit.
Max.

 

I meant the mechanical Hardware, if this is a prototype, if the mechanics are in place as in post #21 then the motors can be sized to suit.
Max.

Prototype 1 is with the drill to test torque
Prototype 2 is pla 3d printed for gears and timing
This is prototype 3 .
I think I will use nema 17s x3, 23s x2 and the planetary geared 34 for the big motor.

It's probably the power source, the drivers and the plc controller I need help to match up to this gear. If you think that motor I showed this morning is better I'll use it. Plus the loop feedback thingy you mentioned.

 

OK guys, I've been reading, and have a more intelligent question.
With stepper motors, will I loose steps and therefore positions when in a motion the torque is varied from Sayyy , 1nm-29nm then back again to 1nm then up to 27nm
Cheers
Mark

 

The answer is yes and no...

Stepper motors have a "Pull Out Torque" limit, exceeding this torque causes the rotor to drop out of synchronism with the magnetic field.
The motor stalls and loses position.

This torque depends on the motor, winding current, driver voltage, stepping speed and acceleration.
One needs to stay well under this torque level to guarantee that the motor doesn't stall.

It's often possible to tune a system to make it work, by adjusting the motion profile to keep it happy.
This is a compromise, as the machine speed may be limited by an undersized motor.

The best bet would be to purchase a stepper indexer, drive and motor as a package, this eliminates so much of the fiddling around.
An indexer generates the stepping signals and move profile, you can just send the thing a high-level command- "move to this position" and it does it for you.

Motion control is a deep and complex subject, buy a solution that matches your skill level, else you face a nasty and expensive learning curve.

 

With stepper motors, will I loose steps and therefore positions when in a motion the torque is varied from Sayyy , 1nm-29nm then back again to 1nm then up to 27nm
Cheers
Mark

The whole idea of steppers is they must have a stepper drive that will maintain the plate rated current (torque) at all times, as the RPM increases the inductive reactance increases, therefore the voltage must be controlled by the drive in order to maintain this rated current (torque).
Modern drives do this automatically, this is why they have a DC supply that is well over the rated voltage of the motor.
If the torque required by the mechanism is more that this rated torque, the motor will drop out of run.
This is why a decent drive should be used such as Gecko etc.
Max.

 

The whole idea of steppers is they must have a stepper drive that will maintain the plate rated current (torque) at all times, as the RPM increases the inductive reactance increases, therefore the voltage must be controlled by the drive in order to maintain this rated current (torque).
Modern drives do this automatically, this is why they have a DC supply that is well over the rated voltage of the motor.
If the torque required by the mechanism is more that this rated torque, the motor will drop out of run.
This is why a decent drive should be used such as Gecko etc.
Max.

So a gecko is a brand of indexer as mentioned above?
Or is an indexer a different pieces of hardware altogether?

 

The answer is yes and no...

Stepper motors have a "Pull Out Torque" limit, exceeding this torque causes the rotor to drop out of synchronism with the magnetic field.
The motor stalls and loses position.

This torque depends on the motor, winding current, driver voltage, stepping speed and acceleration.
One needs to stay well under this torque level to guarantee that the motor doesn't stall.

It's often possible to tune a system to make it work, by adjusting the motion profile to keep it happy.
This is a compromise, as the machine speed may be limited by an undersized motor.

The best bet would be to purchase a stepper indexer, drive and motor as a package, this eliminates so much of the fiddling around.
An indexer generates the stepping signals and move profile, you can just send the thing a high-level command- "move to this position" and it does it for you.

Motion control is a deep and complex subject, buy a solution that matches your skill level, else you face a nasty and expensive learning curve.

Do you have a link to such packages? That would help me get my head round all the pieces of hardware, from the wall socket to the motor shaft.

 

Did you decide on the method for a controller? Arduino etc?
The Gecko link is http://www.geckodrive.com/
You issue the step/dir to them.
Max.

 

Did you decide on the method for a controller? Arduino etc?
The Gecko link is http://www.geckodrive.com/
You issue the step/dir to them.
Max.

I'm thinking, from what I've learnt, and correct me if I'm wrong, I'll not go arduino, I'll go plc, and program with ladder logic?
I suppose I need to work backwards, then find a package type deal. I'm a fan of buying everything from one company.
At this stage I'm waiting for laser cutting companies, bearings and machining, so learning about automation.

 

If going with PLC you need one that has a Stepper module avaialble.
Max.

 

If going with PLC you need one that has a Stepper module avaialble.
Max.

Those gecko drives you linked to me. One per motor right?

 

Correct, they have some info on selecting steppers and drives on the site.
Max.

 

Never used these but evidentally they are cheap, control steppers and AFAIK free S/W.
http://www.aboutplcs.com/directlogic/programmable-logic-controller/dl0506mods/d05l06_specialty.html
Max,

 

Never used these but evidentally they are cheap, control steppers and AFAIK free S/W.
http://www.aboutplcs.com/directlogic/programmable-logic-controller/dl0506mods/d05l06_specialty.html
Max,

Cheers max.
So I need 1 of these and 6 gecko drives?
Then I need a power source

 

Never used these but evidentally they are cheap, control steppers and AFAIK free S/W.
http://www.aboutplcs.com/directlogic/programmable-logic-controller/dl0506mods/d05l06_specialty.html
Max,

Those directlogics only support pulse outputs via expansion I/O, and its one pulse output channel per card. So 5 cards would be needed @ $214/ea. (In addition to the CPU module). The free software only supports 100 words. After that it's $395 for the full featured software, which would probably be needed for this application.

CP1H-X40DR-A from omron has 4 pulse output channels in the PLC itself. If you could find a way to make one of your axes non-servo, you could do it with no expansion I/O. Omron software is not cheap though like directlogics (yeah, $395 is a bargain for PLC software).

I think you are giving up on arduino too soon. If you think learning to program it is too hard, you might want to reevaluate some things. I think you will be sorely disappointed after spending over $1k on a PLC solution and find that it's not that much easier than arduino.

 

Look I keep trying to guide you back to arduino because my impression is that you're just a guy trying to make a living selling rain spouts and you need a machine to get the job done. I'm trying to get you toward the simplest and cheapest solution that works.

If I'm wrong about that; If you are part of a large organization and you've been given a substantial budget to complete this task, then by all means, put a PLC in it.

But this is not a cheap PLC application. It is an expensive PLC application (that a $30 ArduinoMega is fully capable of doing). If you can afford to spend money (I'd budget at least $1500 USD) on this and do it the proper industrial way, let me know and I'll shut up about the Arduino. But if you're willing to give it another shot, below is a reference of how to control stepper drivers with arduino. It describes a "easydriver" board but that can be substituted for any step/dir control like the gecko drivers or chinese drivers.

http://www.schmalzhaus.com/EasyDriver/Examples/EasyDriverExamples.html

 

If you are dirt poor and have months to muck around, go with the Arduino idea. (rhymes with arduous)

I have used the Parker / Compumotor stuff in the past- good stuff:
These units have a wad of features that solve problems you didn't know you were going to have.

Saves heaps of time packaging and wiring up a bunch of boards and random bits too.

http://www.parkermotion.com/products/Stepper_Drive_Controllers__5337__30_32_80_567_29.html

 

If you are dirt poor and have months to muck around, go with the Arduino idea. (rhymes with arduous)

I don't think that's fair. Why would say it would take months? I've tackled several projects with arduino and it was easy peasy in my book. And all I did was copy/paste the widely available example code into my sketch with a few modifications.

My only reasons for staying away from arduino in this application would be :
1. If it is to be sold. I would not want to buy an arduino-controlled machine for the sake of serviceability, and I doubt anyone else would either.
2. If I expect anyone other than myself to be able to troubleshoot it ( I guess that's just a rewording of #1)