Question

Hi guys. Looking to start a project at work on something and would like to get some input on how best to tackle this.

The project is simple x,y control for a small platform. Object is a wafer of silicon and I would like to have a up down and a left right button. Pressing the left right will add or subtract from a counter for Row 1 position 4 will show 1-4 on a display. Row 2 position 5 will show 2-5. It will be under a microscope so microstepping is going to be nessary. Movements will be around 700 microns.

Hardware movements is not an issue. Just looking for some input on what ardrino would be best and what drivers would be best.

-x,y control. Around 700 micron movements. -counter to keep track of the x,y position

You just need any Arduino and some sort of stepper driver. For what you are describing it's the motors and the mechanics that are the hard part. Once you figure that out, then you can decide what sort of driver and arduino to use. You've got the cart before the horse here.

bignaz: Hi guys. Looking to start a project at work on something and would like to get some input on how best to tackle this.

The project is simple x,y control for a small platform. Object is a wafer of silicon and I would like to have a up down and a left right button. Pressing the left right will add or subtract from a counter for Row 1 position 4 will show 1-4 on a display. Row 2 position 5 will show 2-5. It will be under a microscope so microstepping is going to be nessary. Movements will be around 700 microns.

Hardware movements is not an issue. Just looking for some input on what ardrino would be best and what drivers would be best.

-x,y control. Around 700 micron movements. -counter to keep track of the x,y position

I have a customer that does just that for the x and y of a microscope stage. He uses a small stepper with a worm gear.

Paul

How many rows? How many columns? Is it 700 micrometer total or per step?

welcome. it is easy to tell you not read 'how to use this forum' as the subject line will be impossible to draw people who know about 'question' and even harder to reference in a search.

second, do some reading about microstepping. A stepper motor moves in whole, half of quarter steps. it does not micro-step. Micro stepping is a means to attempt to create a pulse that simulates a wave so that the motor moves smootly as it ramps to speed. As soon as power is lost, the motor will move to a whole step location. The magnets in the motor control that simple bit of physics.

You can prove that out very easily, take two magnets and hold one just a fraction off center of the other, then let go. Your hand acts as the stepper driver, but without power, physics takes over and the motor will move to a full step.

700 microns is pretty sloppy in the CNC universe. most people start at about 13 microns and then get higher resolution without trying. A simple 200 step motor on a 10 TPI lead screw with full steps is 2,000 steps per inch. (13 microns), with half stepping, it becomes higher resolution. (6.5 microns) Using a finer pitch will offer much finer resolution. If you need to move under control, then you need to gear the device to be able to move in steps that result in an accuracy you need.

When you HOME or ZERO your movement it should be on a full step and always repeatable.

if you meant to say 1/700th of a micron, then you just need to full step with a worm gear.

Hi, Welcome to the forum.

Please read the first post in any forum entitled how to use this forum. http://forum.arduino.cc/index.php/topic,148850.0.html.

Can you please tell us your electronics, programming, Arduino, hardware experience?

Thanks.. Tom... :)

johnwasser: How many rows? How many columns? Is it 700 micrometer total or per step?

0.7mm is the step and repeat distance I think, so resolution should be much higher than this I would presume. Typical wafer sizes are 3", 4", 6", 8", 12", so many rows and columns.

Backlash is the first problem to worry about on the hardware side, microstepping is always used in precision systems to avoid vibration and noise and wear on the gears/leadscrews, as well as increasing resolution (but it has its limits, position error in a heavily loaded stepper can be a substantial fraction of a step irrespective of step size)

I would recommend precision anti-backlash leadscrews/nuts with a fairly small pitch for this kind of work, high speed rapids are not presumably useful?

To answer the OP's question, any Arduino that supports AccelStepper library, DRV8825 modules (unless the steppers are too small for its minimum current!) I guess something like NEMA11 or 14 might be an appropriate motor size. 12V supply is probably plenty.