Making a Linear Stage

Hi All,

I'm looking to make a linear stage to be used inside an experiment box (acrylic sides and wooden frame).

All of our parts that are inside the experiment box have to be non-metallic.
This is the design. [imgur.com]

The motion in y direction is achieved by running both stepper motors in the same direction, whereas only z-direction stepper motor is turned on to get vertical (z) motion.
Approximate dimension of the system:
55 cm in legth
15 cm in width
25 cm in height

I'd like your opinion/suggestion/remarks on the parts and design.

1) Stepper Motor: [68 Oz.in 400 steps/rev] [www.sparkfun.com]
2) Drivers: [Big Easy Driver] [www.sparkfun.com]
// Controlled by arduino

3) Timing Pulley (x2): [www.robotdigg.com]
4) Timing Belt: [www.robotdigg.com]

4) Plastic timing pulley: This pulley goes inside the box, so it is plastic.
[i.imgur.com]

// I could find this kind of gear [i.imgur.com], so I was thinking I could make a larger hold into spur gear and fit it on the pinion.
5) Bevel Gears: [i.imgur.com]
6) Spur Gear (GT2) - [i.imgur.com]

7) Threaded Rod (Z-direction) = 3/8 - 16 Nylon Threaded Rod
[www.usplastic.com]

8) Acrylic Rods = 9.5 mm Diameter.
9) Acrylic Sheet- 2 mm Thickness.
Support Ends for guide (acrylic rods) will be made out of acrylic sheet as well as the platform.


I'd very much appreciate your comments and suggestion about the design and the parts (if they're right and compatible).

Sincerely,
Kev

If you're already order from robotdigg, they have stepper drivers, motors, arduino and ramps.

RAMPS isn't necessary if he's just hooking up two steppers. It may make any other use of the Arduino harder with the unused RAMPS functionalty taking up pins.

As to the design, just remember you'll need to compensate on the z-axis when the x-axis moves. Otherwise when X moves, Z will spin up or down. If you are writing custom firmware to just control the movement and moving only one axis at a time isn't a problem, then it's easily solved. If you need to be able to move x and z simultaniously it gets more complicated. A long splined shaft that has beveled bearings that run along it might be a work around, but that may not work with your budget, or materials requirement.

Out of curiosity, what is the experiment box for? Does it have to be sealed or can there be open ports that things are ran through just nothing metal on the inside of the box? If it's the latter, you could afix the motor to the top/bottom/side/whatever for the z-axis.

Quote
ejbantz
If you're already order from robotdigg, they have stepper drivers, motors, arduino and ramps.

It looks like Robotdigg is located in China.
Do you know the shipping time and cost to Canada?
Can't find that information.

Edited 2 time(s). Last edit at 06/03/2014 04:58PM by bluehawk91.

Quote
cdru
RAMPS isn't necessary if he's just hooking up two steppers. It may make any other use of the Arduino harder with the unused RAMPS functionalty taking up pins.

As to the design, just remember you'll need to compensate on the z-axis when the x-axis moves. Otherwise when X moves, Z will spin up or down. If you are writing custom firmware to just control the movement and moving only one axis at a time isn't a problem, then it's easily solved. If you need to be able to move x and z simultaniously it gets more complicated. A long splined shaft that has beveled bearings that run along it might be a work around, but that may not work with your budget, or materials requirement.

Out of curiosity, what is the experiment box for? Does it have to be sealed or can there be open ports that things are ran through just nothing metal on the inside of the box? If it's the latter, you could afix the motor to the top/bottom/side/whatever for the z-axis.

The glass slides will be put inside the holder and there would be electrodes behind the glass slide and we're capturing fibers from other end (using voltage difference).
We cannot open the top part. That was the initial thought, but it'd not be possible. Therefore, we've placed motors behind and outside of the box.

We don't need to move x and z simultaneously.
Regarding this,
As to the design, just remember you'll need to compensate on the z-axis when the x-axis moves. Otherwise when X moves, Z will spin up or down.
To correct this, we can turn on both motors (at same speed) when we need to move platform in x axis, otherwise as you said, we get both motions.
We can use this kind of gears with belt touching only top part, so the spur gear will not rotate when both motors are on.
[i.imgur.com]

What do you think of this solution?

Edited 1 time(s). Last edit at 06/03/2014 04:56PM by bluehawk91.

I've ordered from them many times. It usually takes a couple days to get the order placed and payment finalized, but if you stay up late at night you can get the emails back and forth all in one shot. They usually ship by FedEx and it arrives in a few days. Shipping of course depends on the weight, but is like 30USD to the states for a small package of goodies. Not sure about Canada. They will give you quote pretty quick in your night time hours.

Quote
bluehawk91

Quote
ejbantz
If you're already order from robotdigg, they have stepper drivers, motors, arduino and ramps.

It looks like Robotdigg is in located in China.
Do you know the shipping time and cost?
Can't find that information.

Edited 1 time(s). Last edit at 06/03/2014 05:03PM by ejbantz.

Does anyone one know where I can find timing pulley in Toronto, Canada?
Or is SDP-SI the best option?? The shaft on NEMA 17 motor is 5 mm in Diameter. It seems only sdp-si and robot digg has this.