Hardware for 24V 2.5A Stepper Motors

I'm thoroughly confused and could use some guidance. I have a hardware setup that I'm going to repurpose. It is very nice and I don't want to swap out motors. There are 3 stepper motors for XYZ motion that are 24V and 2.5A. I have not built the stepper/extruder yet, but there will probably be only one. Can someone please help me spec out a control board that will give me the most options, control, expansion, ease of configuration.

Bonus requirements: heated chamber control (24V, I think), DC motor/encoder control (I have a very nice motor/encoder extruder setup that would be nice to repurpose). Custom LCD display (existing basic lcd screen on front of machine).

If you guys can throw some ideas or reference material to help me out, that would be great. I would rather customize software/firmware rather than customizing hardware. I'm confused with what challenges are going to be in front of me if I go with something like a DUE with RAMPS-FD and some DVR8825 drivers.

Thanks for any help you can throw my way.

Cheers.

... have you according drivers for your steppers?

I'm driving steppers with an Arduino, powered with 12V (internal 5V) while the drivers+steppers are powered with 325V from their own net-plug PSU ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Quote
VDX
... have you according drivers for your steppers?

I'm driving steppers with an Arduino, powered with 12V (internal 5V) while the drivers+steppers are powered with 325V from their own net-plug PSU ...

I'm sorry, but I don't understand what you mean by according drivers.

I don't know what at net plug PSU is. I'm thinking the arduino is consoling the driver almost like a solenoid and the higher voltage is separate from the 12v arduino power. If so can you please point me to some references to that setup.

Edit: I'm thinking you meant acquired steppers. No I have no drivers

Edited 1 time(s). Last edit at 11/22/2014 04:27PM by TFinleyosu.

I think 'megatronics' can support 24v electronics. But there must be more of that available. I haven't ever worked with megatronics, so I advise to look around a bit

Here:
[reprap.org]

Quote

Specifications

Microcontroller: Atmega2560-16AU
Operating Voltage Electronics:5V
Operating Voltage High:12-24V (15A heated bed, 7A electronics)
DC Current per I/O Pin:40mA
Clock Speed:16Mhz

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http://www.marinusdebeer.nl/

... you can find 'high- voltage' drivers for the steppers, which are powered from a different PSU - the controllers in my CNC-mills and RepStraps are most powered with 5V@1A, while the steppers are powered with 48V@10A or 70V@6A or 325V@2A, depending on the motor-driver-combo ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

What firmware do you use to control the external drivers? It is hard to configure?

There is

Controller --> stepper driver --> stepper motor

24v stepper motor voltage drives stepper motors via driver

Some boards have stepper drivers onboard (plugin pololu drives) RAMPS 1.4 5 drivers
driver could be separate off the board

I don't know of a control board that does DC Motor / encoder and stepper on same board?

Do a little studing?

See RAMPS wiki
[reprap.org]
[reprap.org]
[reprap.org]

I guess I'm confused because of the setup of the "shields" that transfer the source voltage to the drivers through the arduino.

I've read the different wikis but there always seem to be a limitation on one of the boards/shields. So I guess I don't know if it better to find a shield that can handle 24V or use a RAMPS shield with the standard 12V for most things and then route the 24V through the motor shields that are separate from the shield.

Can someone please recommend some hardware?

I think you need a basic stepper motor control tutorial
and a kit to build before you build from scratch!

Please tell us the hardware you have to use?

What existing X, Y, Z hardware and electronics used to control it
NEMA 17 or NEMA 23 motors?
Existing external stepper drivers -- I see -there are NO drivers

RAMPS 1.4 shield gets plugged atop an arduino mega 2560.
The arduino has USB connection to PC, and USB 5V powers the arduino.
The RAMPS shield has two power busses, to power motors
via the stepper drivers (5 driver modules (carriers) on RAMPS -- X, Y , Z axes and 2 extruder motors)
and heaters (extruder/bed) via switching transitors

The driver sends voltage to correct coils in motor to rotate them
as controlled by firmware (Marlin or Repetier) running on the arduino micro controller
as commanded via a stream of g-code from PC software.

RAMPS can use
Pololu DRV8825 Stepper Motor Driver Carrier, High Current

[www.pololu.com]

It operates from 8.2 V to 45 V and can deliver up to approximately 1.5 A
per phase without a heat sink or forced air flow (rated for up to 2.2 A
per coil with sufficient additional cooling).

So with the right power supply you can run motors on up to 45V

But I think you have to understand basic simple system before developing custom system



Edited 1 time(s). Last edit at 11/23/2014 12:59AM by cozmicray.

24v is not and issue on standard RAMPS It you know what your doing...

The caps C3, C4, C6, C7, C9, C10 - 100uF capacitor on the board need to be 35v not the cheaper 16v

The mega is powered from the 12v via D1, for 24v D1 must be removed and the mega powered vi another way (its own power plug for eg)

and the 11amp poly fuse need replaced its only rated for 16v

BUT

The standard pololus will work on 24v no issue, but these will not reach the full 2.5amps, 1.5 the realistic max. you can get DRV 8825 which will do 2amps.
For full 2.5 amps... you will need something else..

Also most steppers you run at much higher voltage than listed... the standard reprap one are rated 1-4v are run on 12 and 24v. So your going to need more than 24volt...

You need 'real' stepper drivers

Edited 1 time(s). Last edit at 11/23/2014 12:36AM by Dust.

keep in mind voltage can spike about 4 to 6 volts above rail voltage. make sure noise on rails is suppressed. also take into account that running a chip at max voltage any load spike can damage driver chip. the best way to avoid over voltage is a diode clamp setup, but this means overshoot is at least 0.6-0.7v. and diode response needs to be fast!

Edited 1 time(s). Last edit at 11/23/2014 03:48AM by jamesdanielv.

Nobody has any idea about Megatronics?

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http://www.marinusdebeer.nl/

Thank you everyone for the suggestions and explanations.

I have 2 Applied Motion stepper motors (MN23-700-002) and a Lin Enginering stepper motor (5718M-24P-03RO). I am waiting to get the specs from Applied Motion but the Lin Engineering motor is 24V and 2.43A.

I think I need to identify the right stepper drivers if the DVR8825 is not an option.

24 volts at 2.43 amps looks wrong.
See this link [www.linengineering.com]
5718M 4 wire motors are 173 oz-in
5718M-05P is 2.8 amps at 0.9 ohm = 2.5 volts (i*v) or 7 watts (i*i*r)
5718M-02S is 2.1 amps at 1.8 ohm = 3.8 volts or 8 watts
24V * 2.43amps = 9.8 ohm or 58 watts
Measure the resistance of the coils

George

The resistance shows 1.5 ohm

... so the stated voltage won't fit - this seems to be common steppers, which should be happy with the normal 12V/1.5A-drivers too

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Could I just go with 3 of these controlled by my arduino to be safe?

TB6560: [www.amazon.com]

Quote
VDX
... so the stated voltage won't fit - this seems to be common steppers, which should be happy with the normal 12V/1.5A-drivers too

Somethings going on, but the previous system used a 24V power supply ... so that's weird

I just put a request into Lin Engineering for a data sheet for the motor

Those would be safe, but possibly not necessary.
Note that you do not need to run your steppers up to the full current rating. I have similar Nema23 steppers and am running them using 8825 drivers.

I am using a Rumba, but really I would recommend a Smoothie. It's a 32 bit controller and will do everything that the Ramps etc will do much easier, since it will not be running into 16mhz 8-bit overhead. It has outputs that can be used to run external drivers. It can run a full graphic display without slowing down like the Arduino based controllers. I'm planning on upgrading to a Smoothie.

For a servo motor (I assume is for the extruder) you will need to run an external driver like a Gekko. It might be easier to use a stepper instead.

Edit:
Note that the increased voltage will allow higher speeds, increased current gives added torque. Steppers are always run over their current rating, since the drivers use a chopper circuit that controls the current.

Edited 1 time(s). Last edit at 11/23/2014 05:42PM by Paul Wanamaker.

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My printer: Raptosaur - Large Format Delta - [www.paulwanamaker.wordpress.com]
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The voltage listed on the steppers is normaly just the current * resitance

you have said the current is 2.43 and the resitance is 1.5

ie V = 2.43 * 1.5
= 3.645 volts

This makes more sense. as you can drive that from a 24v supply no issues.
So driving this form a drv8825 stepper driver should be fine (even if a little curent limited)

Thank you for you help guys.. What board would you guys recommend for a 24V supply and 8825 drivers? It doesn't look like the smoothie uses 8825 drivers and I'm not sure how extensive the 24V mod is for the RAMPS board.

Edited 1 time(s). Last edit at 11/23/2014 10:09PM by TFinleyosu.

Steppers work on magnetic force from coils of wire. If you feed 3.6 volts at 2.4 amps to the motor it would have full holding power.
To step the motor you reverse the direction of current in the coils. At 3.6 volts this would take a long time so motor would be very slow.
By using a higher voltage the current can be changed quicker and the motor can run much faster. The higher the voltage the faster the maximum speed is. The job of the driver circuit is to stop the current as soon as it hits the maximum allowed , 2.43 amps in your case.
The coil will release its stored current over time and the controler will refresh it to keep the average at the maximum. There used to be a rule of thumb of 20 times stepper voltage for the power supply maximum.

Quote
george4657
Steppers work on magnetic force from coils of wire. If you feed 3.6 volts at 2.4 amps to the motor it would have full holding power.
To step the motor you reverse the direction of current in the coils. At 3.6 volts this would take a long time so motor would be very slow.
By using a higher voltage the current can be changed quicker and the motor can run much faster. The higher the voltage the faster the maximum speed is. The job of the driver circuit is to stop the current as soon as it hits the maximum allowed , 2.43 amps in your case.
The coil will release its stored current over time and the controler will refresh it to keep the average at the maximum. There used to be a rule of thumb of 20 times stepper voltage for the power supply maximum.

That helps a lot with regard to the confusion of the motor specs.

Do you think I'll run into any issues using the 8825 above the rated max of 2.2A?

Actually, could I clarify one thing. The motor will try to pull 2.4 amps but the driver is only rated at 2.2 max. Will it actually only allow 2.2, or will it pull 2.4 and cause it to overheat (maybe miss steps???). Or will it only let 2.2 amps through and just cause the motor to have less holding power and maybe a little speed compromise.

The driver will put out up to it's rated max only, and only then if it is extremely well heatsinked with strong fan. Even then it will not quite do the max.
When it's near its max it will overheat, and it's thermal protection will cut the voltage until it cools off. In my experience for about a second. This is a possible source of lost steps.
If you run drivers rated at 2A with 2.5A motors, you are just not going to go over 2A, and will not get the max torque from the motors, but the motors will be just fine.

Edit:
It will have less holding power, but it's the voltage that determines the max speed.

Edit:
FYI: The Azteeg X5 is based on Smoothie, and has 8825 drivers.
According to this wiring diagram it can take up to 30v.

Edited 2 time(s). Last edit at 11/24/2014 12:47AM by Paul Wanamaker.

What type of application requires using these High Current motors.
Are you CNC milling titanium with 1" depth cuts?

Not much current required
to push/pull an extruder around?
or
Squirt ABS out of extruder?

He's rebuilding a Stratasys printer.

Please note : while Smoothieboard's drivers are rated up to 2A, and TI-based drivers are rated up to 2.5A, it is important to note that Smoothie has more cooling surface area, allowing it to reach those full 2A, while TI-based drivers used on smaller boards or very small breakouts might not even be able to reach 2A ( while being rated for a full 2.5A ) due to difficulties in evacuating heat efficiently.