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Main => General Discussion Board. => Topic started by: Trevor Hale on February 17, 2018, 09:01:28 AM

Title: New Compass for King Air
Post by: Trevor Hale on February 17, 2018, 09:01:28 AM
Hi Guys.


Well Printer has just paid for itself once again. I have always wanted to have a Compass in the cockpit but the $400usd price tag was always just a bit crazy in my mind.


Well, I think this is just as good.


What do you think.



Title: Re: New Compass for King Air
Post by: Ed on February 17, 2018, 11:10:09 AM
Quote from: Trevor Hale on February 17, 2018, 09:01:28 AM
Hi Guys.


Well Printer has just paid for itself once again. I have always wanted to have a Compass in the cockpit but the $400usd price tag was always just a bit crazy in my mind.


Well, I think this is just as good.


What do you think.

I think it looks pretty darn great! Are the internals interfaced to the sim? I'm getting close to wanting one of these 3D printers.  arraghh
Title: Re: New Compass for King Air
Post by: Trevor Hale on February 17, 2018, 12:42:52 PM
Yes, its completely interfaced to my Arduino Card.  The thing is, and this is a concession I have personally made, is that generally you would install a stepper motor, so that it can do continious rotation.  I have made the concession of installing a servo, which can only go 180 degrees, so in my programming the unit when it gets all the way to 359 degrees, the servo quickly swings to the other end of the travel and continues...

But thats just a simple mater of programming...

But yeah, does what I need to do..  More eye candy than anything.
Title: Re: New Compass for King Air
Post by: Joe Lavery on February 17, 2018, 02:05:15 PM
Hey Trev, if it works, it works.... Looks good to me  8) 8)
Title: Re: New Compass for King Air
Post by: Sam Llorca on February 19, 2018, 02:09:48 AM
 :o  :'(

Awesome! No way, that's it!, I need a friend with a 3D printer!
Title: Re: New Compass for King Air
Post by: Ed on February 19, 2018, 02:22:24 AM
Yes, it's getting very very difficult to resist the urge to order up a 3D Printer.
Title: Re: New Compass for King Air
Post by: Trevor Hale on February 19, 2018, 05:03:35 AM
Quote from: Sam Llorca on February 19, 2018, 02:09:48 AM
:o :'(

Awesome! No way, that's it!, I need a friend with a 3D printer!


Hey!!!!  You have friends with printers bro lol.
Title: Re: New Compass for King Air
Post by: _alioth_ on February 19, 2018, 09:01:08 AM
Good work.
Why not use a.... Real one?!!
Time to time, it is posible to get a real one in ebay for 30-50€.
I have a real one. With a magnet under the compass, that spins with a  gearbox DC motor and absolute encoder in my case. A stepper motor can be used, of course. Working with arduino.
A little more work in programming that servo solution, but real 360 degree rotation.

It works perfect... and I can't be more real.

I can upload a vid, if you want.

Title: Re: New Compass for King Air
Post by: Trevor Hale on February 19, 2018, 01:05:13 PM
Thanks bud..  Yes I could have gone that route also...  May in the future...
Title: Re: New Compass for King Air
Post by: Ed on February 19, 2018, 01:11:55 PM
Quote from: _alioth_ on February 19, 2018, 09:01:08 AM
Good work.
Why not use a.... Real one?!!
Time to time, it is posible to get a real one in ebay for 30-50€.
I have a real one. With a magnet under the compass, that spins with a  gearbox DC motor and absolute encoder in my case. A stepper motor can be used, of course. Working with arduino.
A little more work in programming that servo solution, but real 360 degree rotation.

It works perfect... and I can't be more real.

I can upload a vid, if you want.

Hi Arturo,

I'd be very interested in how you set up the magnet system with your compass. Do you have plans for it?

Thanks,
Ed
Title: Re: New Compass for King Air
Post by: _alioth_ on February 19, 2018, 11:56:44 PM
Quote from: Ed on February 19, 2018, 01:11:55 PM
Quote from: _alioth_ on February 19, 2018, 09:01:08 AM
Good work.
Why not use a.... Real one?!!
Time to time, it is posible to get a real one in ebay for 30-50€.
I have a real one. With a magnet under the compass, that spins with a  gearbox DC motor and absolute encoder in my case. A stepper motor can be used, of course. Working with arduino.
A little more work in programming that servo solution, but real 360 degree rotation.

It works perfect... and I can't be more real.

I can upload a vid, if you want.

Hi Arturo,

I'd be very interested in how you set up the magnet system with your compass. Do you have plans for it?

Thanks,
Ed


Here is an old vid with the compass working towards the hsi and rmi:
https://www.youtube.com/watch?v=aYK5VmCKFMA&t=374s (https://www.youtube.com/watch?v=aYK5VmCKFMA&t=374s)


No plans, but dont need it.
This was from and old ast simulator. There is a dc motor with gear box under the compass, which rotates a magnet. To read the position the original gauge had a synchro resolver. As I dont know how to read a synhcro resolver and very special hardware (400hz AC power supply ) is needed, I change the resolver to a moderm absolute encoder, very easy to read with arduino.

Another way to make it work is using an stepper motor and homing sensor. Easier sure.

Software process with arduino:

-Read heading in simulator.
-Read absolute encoder position.
-Compare both positions to know if you have to move dc motor CW or CCW.
-Move the motor, through a motor driver like l298n or similar.
-I move the motor faster if the position is far, and very slow if it is very near, and stops if they are in the same position.

As the compass has its fluid inside, the movement is very realistic.

Arturo.