Where to find small steppingmotors for DIY instruments?

[Steve Andrew]

Hi

These steppers should be small enough and most are 1.8 deg/step: www.pololu.com/catalog/category/87

A very good range of small plastic gears can be found at www.gizmoszone.com/shopping/agora.cgi?

Hope this helps..

Best regards... Steve

[jaspar]

Twisted8
thats a smooth running wet compass.
im looking to start learning to build some instruments myself and learn how to interface and program for them.

looking to start simple with a compass ASI and N2 tach meter all based on stepper motors.

do you have any tutorials or drawings for your compass that you are willing to share with us.( i already have mike powels book for insperation )

[twisted8]

Thank you! I'll put more info together but here is basics.
Parts needed:
- 1 Opencockpits stepper motor USB card
- 1 Small Stepper Motor
- 1 Optical Sensor (HOA2001-001)
- 1 set of gears (i used these)
- Plexiglass, spacers, a rod and bolts

I used the opencockpits stepper motor cards so that takes care of all the electronics. As far as the mechanical part I used 3 layers of plexi glass being held together with spacers. I have a small gear attached to stepper motor and a bigger gear with a rod attached going all the way down to the wet compass (or to your gauge needle). The picture should explan it better. On the base part I made a simple needle out of thin plastic to trigger the optic sensor (not visible on the picture), this is required with the opencockpit cards. When the rod spins, it spins the needle that trigges the sensor.
The only hard part is aligning the gears so they move smoothly, but it just basic meassurements and drilling the right holes.




This is the system for the flaps gauge, same thing but flipped around. Here you can see how the optical sensor works



Hope this helps!

[jaspar]

thanks twisted8
just looked up the opencockpits board and it looks like you just pointed me to the place to solve my biggest headache. was not looking forward to having to prototype PCB's for mike powell's circuits. so it looks like i'll gow with the mechanical assy from mikes book but use OC stepper and servo cards for the interfacing.

jaspar

[twisted8]

Not a problem, I agree that's the way to go!