electronics for my project

Hello!

I'm new of the world around the 3d printer

I made ​​a clear idea of what I need especially electronics.


I would like some advice on the driver of the stepper motors .

I have read around that there are some different type of this driver such as A4988 etc ... What's the difference between them?

In particular, what should I buy if I will use a RAMPS 1.4?

I've seen cards RAMPS coupled with these drivers A4988 . What do you think ?


I would like to start buying something. I decided that I want to start by the electronic buying an Arduino compatible board ( Mega version , not the ONE) .

What do you think ?

After the Arduino compatible board, i will buy a RAMPS 1.4 and next the drivers and the other things.

For motors i want to take its from some old inkject printers ( 1 HP , 1 Canon , Epson 1 ).

Is It possibile to do this?
Fans and circuitry varies I will recycle from stuff that I have in the garage ( power supply too). Yes, my garage is a repository of electronic stuff XD

Thank you in advance

Edited 2 time(s). Last edit at 10/22/2013 09:38AM by DeAndreon.

You may not find any steppers in older inkjet printers. If you do they might be underpowered for our purposes. It doesn't hurt to try though. Sounds like a perfectly reasonable plan. Pololu.com generally has a black friday sale, which would be a good time to get the drivers. They are the original designer/supplier of the A4988 driver boards we use for stepper drivers. That's why you will often hear them called "Pololu's"

Bryan

Hello! Thank for your answer

Yesterday i opened an older Canon and i found two stepper motors

But i don't know anything about them.

On internet i find this:

[www.datasheetarchive.com]

this is the datasheet of the chip that control them.


They are bipolar because they have 4 wires..

These are their name::

QH4-9007 T9625-01
17PU-HO12-P1ST

PATENT PENDING
MINEBEA CO. LTD.
I think they work with 24 v because on the back of the printer there is:

24v ----- 0.83A
- - - -

24v ------ 0.76A
- - - -
Thery are good for my project?

Thank you in advance

If they really are 24V steppers you might have a hard time driving them with standard reprap electronics. Generally with current limiting drivers like the pololu's you want the drive voltage to be larger than the stepper rated voltage. This allows the duty cycle to be less than 100% so the current limiting circuit can do its job. Check the resistance of the coils and you'll get an idea of the working voltage. Less than 4 or 5 ohm per coil is likely less than 12V as most steppers use from 0.5 to 2 amps max current. Are they nema 17 size or larger? If not you might not get enough torque.

Edited 1 time(s). Last edit at 10/23/2013 10:33AM by bryanandaimee.

Pololu drivers should work up to 30V, so the drivers are capable of running motors at 24V.

The main issue is whether the rest of the electronics are capable.

1. The electronics itself needs to handle 24V. Even some of the ones that handle 24V should be checked that all necessary components support 24V (cheap sellers replace the components with ones that are specced at a lower voltage, because they are cheaper).

2. If the electronics connects to other boards, and feeds them power (eg: An Arduino Mega) you either need to know that the electronics cuts the voltage down to a suitable value to suit the other boards, or that other boards are capable of dealing with that voltage.

3. See if the electronics has multiple inputs for voltage, and what each input drives. If they're all the same, you most likely need to use external components (hot end, heated bed, etc) that are 24V suitable (different heater cartridges or different value resistor blocks, suitable heated bed, cooling fans, etc). Some have multiple inputs, so you need to see what drives what and change your external components as necessary.

eg: RAMPS 1.3/1.4 has 2 inputs. 1 for heated bed, 1 for hot end/fan/motors/Arduino Mega. If you want to run the motors at 24V, you need to use suitable parts for the hot end, fan and Arduino Mega that can handle 24V. FWIW: RAMPS also has other problems with 24V that should be checked/addressed before you use it at 24V. That said, I have my RAMPS board running at 24V no problem (with only minor changes), for all external components (hot end, fan, motors, heated bed).


Note: Going to 24V isn't as simple as it should be, but some of the electronics out there are better suited for 24V than others, and the people designing electronics for Reprap are getting better at allowing for 24V systems in their designs.