Project similar to delta 3d printer - driving stepper motor question

Hi everyone,

I am a programmer who is pretty new to electronics and arduino. I’m interested in jumping into the deep end on this. Also new to the forums - hi!

I wanted to ask some questions which I hope aren’t too generic, trying to get an overview of what I need to buy. I am relatively confident that once I own the parts I will be able to put them together - possibly with some help from the community :slight_smile: .

What I am trying to build is effectively a delta robot based on the common delta 3D printer designs - except this is not going to be a 3D printer, I only need the frame and the motors - none of the other electronics or printing bits.

I would like to be able to move the ‘hand’ in real time - for example by inputting an x, y and z coordinate via serial from an external device - or via a joystick, something to that affect.

I have seen a guide like THIS which shows how I can create a reasonably cheap prototype frame, but like most 3D printers this uses the RAMPS 1.4 shield designed for 3D printers.

So my question really is - what is the best way for me to drive 3 X low voltage, high torque stepper motors using an arduino to achieve what I have mentioned above?

Can I buy a RAMPS shield and just use it as a motor shield, ignoring the other electronics? Will RAMPS be easy for me to interface with - as I will not just be installing 3D printer software. Or is there another stepper motor shield I should be considering instead which would achieve what I am aiming for?

I saw the adafruit motor shield available, but it doesn’t look like it will be able to drive the low voltage motors used in the 3D printing guides I have seen.

Sorry if this has been asked before in another round about way. I hope I can get some answers.

Thanks

Can I buy a RAMPS shield and just use it as a motor shield, ignoring the other electronics?

Yes.

Will RAMPS be easy for me to interface with

Yes (for some definitions of easy). The board plugs onto a Mega board like any other shield. The pins are identified on the schematic.

Or is there another stepper motor shield I should be considering instead which would achieve what I am aiming for?

The "Grbl shield" that fits onto an Uno is a simpler (than Ramps) CNC shield that will accept 4 stepper drivers (for 3 axis).

kepha:
So my question really is - what is the best way for me to drive 3 X low voltage, high torque stepper motors using an arduino to achieve what I have mentioned above?

First you MUST identify the motors that are required. No RAMPS or GRBL shield will be any use unless the stepper motor drivers they take are capable of comfortably supplying the current required by your chosen motors.

Drivers for more powerful motors will be considerably more expensive but they are controlled by the Arduino in the same way - with step and direction signals.

...R
Stepper Motor Basics
Simple Stepper Code

Robin2:
First you MUST identify the motors that are required. No RAMPS or GRBL shield will be any use unless the stepper motor drivers they take are capable of comfortably supplying the current required by your chosen motors.

Thanks Robin, I guess I was planning on buying the same motors used in the guide I linked which are these: http://www.zappautomation.co.uk/sy42sth47-1684a-high-torque-hybrid-stepper-motors.html

I don't know a great deal about them in general so I will give your links a read - those motors should be sufficient enough for my use if they are sufficient for the author of that guides use. If this doesn't turn out to be the case then at least I have a benchmark to work from to further understand what the numbers mean in practical terms.

I suspect those 1.68 amp motors will be close to the limit for the DRV8825 - do you have heat sinks on your chips? A cooling fan may also be a good idea.

...R