Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then.
Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive.
This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc.
I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high.
I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition?
I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ?
73 de N3RDX George Washington University
Hi Samudra,
See: http://home.wavecable.com/~ko6th Near the top of the page, on the left, are links to the design document and code source for what I created. It's not a kit, but rather a discusson of the various pieces needed to make such a controller, which you can adapt as needed to whatever hardware you can get your hands on. The Alliance U-110 makes for a great Elevation rotor, and there are many Az rotors that can be had for very low cost. Alternatively, as long as you can supply a contact closure every 6-10 degrees of rotation, this system can be adapted to a variety of mechanical contraptions. Let the students and faculty get creative!
Good luck,
Greg KO6TH
Samudra Haque wrote:
Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then.
Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive.
This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc.
I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high.
I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition?
I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ?
73 de N3RDX George Washington University _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Thank you Greg and Art for your suggestions. I'm interested to pursue the standard mechanism (AZ-EL rotors) but also want to inquire about any recent robotics work in this area ? A 2-link robot with a rotary joint manipulator that would point an antenna , could be a candidate solution - with no problems for normal/flip mode. I have some minor experience to use in this area - any collaboration possibilities ?
On Sat, Feb 23, 2013 at 7:58 PM, Greg D ko6th.greg@gmail.com wrote:
Hi Samudra,
See: http://home.wavecable.com/~**ko6th http://home.wavecable.com/~ko6thNear the top of the page, on the left, are links to the design document and code source for what I created. It's not a kit, but rather a discusson of the various pieces needed to make such a controller, which you can adapt as needed to whatever hardware you can get your hands on. The Alliance U-110 makes for a great Elevation rotor, and there are many Az rotors that can be had for very low cost. Alternatively, as long as you can supply a contact closure every 6-10 degrees of rotation, this system can be adapted to a variety of mechanical contraptions. Let the students and faculty get creative!
Good luck,
Greg KO6TH
Samudra Haque wrote:
Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then.
Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive.
This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc.
I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high.
I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition?
I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ?
73 de N3RDX George Washington University ______________________________**_________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/**listinfo/amsat-bbhttp://amsat.org/mailman/listinfo/amsat-bb
Samudra and the gang, The bee's knees would be an Arduino Mega 2560 talking over one of it's serial ports to the pc. Using the output of the Orbitron (or insert your fave rave software here) DDE server to drive the microcontroller. There are enough digital/analog pins to drive/slave anything from there. Simple serial port setup. Repeatable. Extensible. The chip has several other HARDWARE (i.e has it's own hardware buffers for i/o) serial ports for more and more fun stuff. Have a look on youtube or google for code to drive steppers / selsyns.. Norm n3ykf
I think AMSAT-UK even has software available.
And with the addition of a bit of EEPROM, you could even pre-load the controller with ephemeris data for several satellites for several days in advance. Emergency / field-day / portable operation without needing a computer.
Add a bluetooth module and an Android app, and you could have an all singing, all dancing, full-featured satellite station in a briefcase.
I'D buy one...
On 02/23/2013 10:01 PM, Lizeth Norman wrote:
Samudra and the gang, The bee's knees would be an Arduino Mega 2560 talking over one of it's serial ports to the pc. Using the output of the Orbitron (or insert your fave rave software here) DDE server to drive the microcontroller. There are enough digital/analog pins to drive/slave anything from there. Simple serial port setup. Repeatable. Extensible. The chip has several other HARDWARE (i.e has it's own hardware buffers for i/o) serial ports for more and more fun stuff. Have a look on youtube or google for code to drive steppers / selsyns.. Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Gus, These days is the hardware can all be made to chat with other bits of hardware. Doesn't matter which IDE/mfgr that gets chosen for the product we're talking about. Most these days can be made to do the same thing with some code.
You bring about a good point. A contraption (az el rotator) can be driven with a smart phone. Not sure the radios could be driven that way. Not much of a hindrance, though.
The key is that the modules are off the shelf, cheep, supported and can be for the most part purchased at Radio Shack/downloaded from the internet. (shameless plug: they have microcontrollers in stock along with a pretty good line electronics goodies.)
Norm n3ykf
On Sat, Feb 23, 2013 at 9:35 PM, Gus 8p6sm@anjo.com wrote:
I think AMSAT-UK even has software available.
And with the addition of a bit of EEPROM, you could even pre-load the controller with ephemeris data for several satellites for several days in advance. Emergency / field-day / portable operation without needing a computer.
Add a bluetooth module and an Android app, and you could have an all singing, all dancing, full-featured satellite station in a briefcase.
I'D buy one...
On 02/23/2013 10:01 PM, Lizeth Norman wrote:
Samudra and the gang, The bee's knees would be an Arduino Mega 2560 talking over one of it's serial ports to the pc. Using the output of the Orbitron (or insert your fave rave software here) DDE server to drive the microcontroller. There are enough digital/analog pins to drive/slave anything from there. Simple serial port setup. Repeatable. Extensible. The chip has several other HARDWARE (i.e has it's own hardware buffers for i/o) serial ports for more and more fun stuff. Have a look on youtube or google for code to drive steppers / selsyns.. Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
-- 73, de Gus 8P6SM Barbados, the easternmost isle.
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Gus,
Check this out.
http://www.tomdoyle.org/simplesattracker/SimpleSatTracker.html
73 W9KE tom...
On Sat, Feb 23, 2013 at 8:35 PM, Gus 8p6sm@anjo.com wrote:
I think AMSAT-UK even has software available.
And with the addition of a bit of EEPROM, you could even pre-load the controller with ephemeris data for several satellites for several days in advance. Emergency / field-day / portable operation without needing a computer.
Add a bluetooth module and an Android app, and you could have an all singing, all dancing, full-featured satellite station in a briefcase.
I'D buy one...
On 02/23/2013 10:01 PM, Lizeth Norman wrote:
Samudra and the gang, The bee's knees would be an Arduino Mega 2560 talking over one of it's serial ports to the pc. Using the output of the Orbitron (or insert your fave rave software here) DDE server to drive the microcontroller. There are enough digital/analog pins to drive/slave anything from there. Simple serial port setup. Repeatable. Extensible. The chip has several other HARDWARE (i.e has it's own hardware buffers for i/o) serial ports for more and more fun stuff. Have a look on youtube or google for code to drive steppers / selsyns.. Norm n3ykf ______________________________**_________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/**listinfo/amsat-bbhttp://amsat.org/mailman/listinfo/amsat-bb
-- 73, de Gus 8P6SM Barbados, the easternmost isle.
______________________________**_________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/**listinfo/amsat-bbhttp://amsat.org/mailman/listinfo/amsat-bb
Thanks, Tom!
On 02/24/2013 10:22 AM, Thomas Doyle wrote:
Gus, Check this out. http://www.tomdoyle.org/simplesattracker/SimpleSatTracker.html 73 W9KE tom...
On Sat, Feb 23, 2013 at 8:35 PM, Gus <8p6sm@anjo.com mailto:8p6sm@anjo.com> wrote:
I think AMSAT-UK even has software available. And with the addition of a bit of EEPROM, you could even pre-load the controller with ephemeris data for several satellites for several days in advance. Emergency / field-day / portable operation without needing a computer. Add a bluetooth module and an Android app, and you could have an all singing, all dancing, full-featured satellite station in a briefcase. I'D buy one... On 02/23/2013 10:01 PM, Lizeth Norman wrote: Samudra and the gang, The bee's knees would be an Arduino Mega 2560 talking over one of it's serial ports to the pc. Using the output of the Orbitron (or insert your fave rave software here) DDE server to drive the microcontroller. There are enough digital/analog pins to drive/slave anything from there. Simple serial port setup. Repeatable. Extensible. The chip has several other HARDWARE (i.e has it's own hardware buffers for i/o) serial ports for more and more fun stuff. Have a look on youtube or google for code to drive steppers / selsyns.. Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb -- 73, de Gus 8P6SM Barbados, the easternmost isle. _______________________________________________ Sent via AMSAT-BB@amsat.org <mailto:AMSAT-BB@amsat.org>. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb--
Sent from my computer.
tom ...
Given the shortage of LEO birds, exactly how much antenna do we need to rotate?
Hams operate satellite successfully with hand-held antennas, which have low wind-loading and are light in weight.
With R/C servos available producing 6½ ft. lb of torque for less than 150 bucks, I'm surprised a light weight, portable, DC-operated satellite system complete with antennas and AZ/EL rotors hasn't materialized before now.
On 02/23/2013 07:59 PM, Samudra Haque wrote:
Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then.
Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive.
This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc.
I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high.
I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition?
I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ?
73 de N3RDX George Washington University _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf
I hope it is evident, I am not focusing on the controller/microcontroller/computer interface/az-el controller/etc. The real issue is how cheaply can an antenna be mounted on a kingpost somewhere on a surface, with a view towards the sky, and how conveniently can that mount be motorized, with a sensor to give feedback to the ground station. electronics, seem to be, (apologises to EE friends) a dime a dozen, cheaper if made in hundreds, but the key drawback of any design is the mechanical and electromechanical (can we use, mechatronics) system that serves as the actuators. I am not referring to a hand held antenna assembly, but rather something that we can all use in cold/hot weather and that can be put together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu based cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman normanlizeth@gmail.comwrote:
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Samudra, This is a good question for a first year engineering student like myself: How does one bring home the best bang for the buck out of an engineering dollar?
Feel free to ask around. A few on the list have driven unusual devices to get antennas moved.
How does a project get into the hands of people who will actually do it? A one off I can do for you in my basement. Probably with parts from radio shack, a grinder and a few hand tools.. A reproducible project 10 years from now? Hardly likely.
I submit to you that irrespective of the metalwork this is a simple project as you propose, however it must be reproducible. With a student copy of SolidWorks, a circular saw, drill and the Arduino IDE it could be prototyped by two people in a weekend. Refining it so that a relatively new ham with a smidgin of technical ability could do it might take a little longer. These days with the internet and cad, the real issue is the tooling. How do you design/layout such that it can be done with snips/file/saw/fill in the blunt instrument here.. 73 es have fun..
Norm n3ykf
On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque samudra.haque@gmail.com wrote:
I hope it is evident, I am not focusing on the controller/microcontroller/computer interface/az-el controller/etc. The real issue is how cheaply can an antenna be mounted on a kingpost somewhere on a surface, with a view towards the sky, and how conveniently can that mount be motorized, with a sensor to give feedback to the ground station. electronics, seem to be, (apologises to EE friends) a dime a dozen, cheaper if made in hundreds, but the key drawback of any design is the mechanical and electromechanical (can we use, mechatronics) system that serves as the actuators. I am not referring to a hand held antenna assembly, but rather something that we can all use in cold/hot weather and that can be put together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu based cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman normanlizeth@gmail.com wrote:
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
hi, thanks for addressing this question. And I invite others to participate, or get in touch with me for a phone conversation, and discuss simple steps that can be taken IMHO within 50-100 USD. I suggest we adopt AMSAT friendly tips:
http://www.amsat.org/amsat-new/tools/downloads/iROTOR.pdf (will need additional interface to PC, any kind)
(cool idea, but only as concept) http://www.amsat.org/amsat-new/echo/Az_El_Pos.pdf
http://dgg.gotdns.com/doc/XOX_rotor.pdf (Semi professional..)
http://ka6puw.tripod.com/azimuth1.html <--- what do you think of this style? Looks simple enough.
But I have only done a simple google search here. Any other projects worth investigating? Focus on the "mount" only now.
-samudra
On Sat, Feb 23, 2013 at 10:41 PM, Lizeth Norman normanlizeth@gmail.comwrote:
Samudra, This is a good question for a first year engineering student like myself: How does one bring home the best bang for the buck out of an engineering dollar?
Feel free to ask around. A few on the list have driven unusual devices to get antennas moved.
How does a project get into the hands of people who will actually do it? A one off I can do for you in my basement. Probably with parts from radio shack, a grinder and a few hand tools.. A reproducible project 10 years from now? Hardly likely.
I submit to you that irrespective of the metalwork this is a simple project as you propose, however it must be reproducible. With a student copy of SolidWorks, a circular saw, drill and the Arduino IDE it could be prototyped by two people in a weekend. Refining it so that a relatively new ham with a smidgin of technical ability could do it might take a little longer. These days with the internet and cad, the real issue is the tooling. How do you design/layout such that it can be done with snips/file/saw/fill in the blunt instrument here.. 73 es have fun..
Norm n3ykf
On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque samudra.haque@gmail.com wrote:
I hope it is evident, I am not focusing on the controller/microcontroller/computer interface/az-el controller/etc. The
real
issue is how cheaply can an antenna be mounted on a kingpost somewhere
on a
surface, with a view towards the sky, and how conveniently can that
mount be
motorized, with a sensor to give feedback to the ground station. electronics, seem to be, (apologises to EE friends) a dime a dozen,
cheaper
if made in hundreds, but the key drawback of any design is the mechanical and electromechanical (can we use, mechatronics) system that serves as
the
actuators. I am not referring to a hand held antenna assembly, but rather something that we can all use in cold/hot weather and that can be put together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu
based
cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman normanlizeth@gmail.com wrote:
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the
author.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Samudra, It's an interesting question as to how much antenna that can be hung on those gearhead motors. At 20 bux plus shipping, that's reasonable for a hobbist budget. need two, the cable and metal (cool how the worst of the metal work is done for you with KA6PUW's design.) Need to do a BOM but should work out less than 100$ Probably kit it for less, particularly the metal bits. Cheaper to buy by the 100's of feet, of course.
The reference to SolidWorks is that the math needs to be worked out regarding the shaft torque. Haven't been that far yet.
A thought is to have three build scales. One portable. One for home/regular sized arrays, and a monster, no expenses spared version. This is pretty easily doable with the electronics package you suggest, just a different ,motor drive block, assuming DC motors and some sort of feedback loop.
Curious to know, but the budding ECE in me wants to know what development environment / microcontroller product families are in consideration. The processors keep getting smaller and smaller. What about a rasberry pi with a display in HD??? Amazing..
Norm n3ykf
On Sat, Feb 23, 2013 at 11:03 PM, Samudra Haque samudra.haque@gmail.com wrote:
hi, thanks for addressing this question. And I invite others to participate, or get in touch with me for a phone conversation, and discuss simple steps that can be taken IMHO within 50-100 USD. I suggest we adopt AMSAT friendly tips:
http://www.amsat.org/amsat-new/tools/downloads/iROTOR.pdf (will need additional interface to PC, any kind)
(cool idea, but only as concept) http://www.amsat.org/amsat-new/echo/Az_El_Pos.pdf
http://dgg.gotdns.com/doc/XOX_rotor.pdf (Semi professional..)
http://ka6puw.tripod.com/azimuth1.html <--- what do you think of this style? Looks simple enough.
But I have only done a simple google search here. Any other projects worth investigating? Focus on the "mount" only now.
-samudra
On Sat, Feb 23, 2013 at 10:41 PM, Lizeth Norman normanlizeth@gmail.com wrote:
Samudra, This is a good question for a first year engineering student like myself: How does one bring home the best bang for the buck out of an engineering dollar?
Feel free to ask around. A few on the list have driven unusual devices to get antennas moved.
How does a project get into the hands of people who will actually do it? A one off I can do for you in my basement. Probably with parts from radio shack, a grinder and a few hand tools.. A reproducible project 10 years from now? Hardly likely.
I submit to you that irrespective of the metalwork this is a simple project as you propose, however it must be reproducible. With a student copy of SolidWorks, a circular saw, drill and the Arduino IDE it could be prototyped by two people in a weekend. Refining it so that a relatively new ham with a smidgin of technical ability could do it might take a little longer. These days with the internet and cad, the real issue is the tooling. How do you design/layout such that it can be done with snips/file/saw/fill in the blunt instrument here.. 73 es have fun..
Norm n3ykf
On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque samudra.haque@gmail.com wrote:
I hope it is evident, I am not focusing on the controller/microcontroller/computer interface/az-el controller/etc. The real issue is how cheaply can an antenna be mounted on a kingpost somewhere on a surface, with a view towards the sky, and how conveniently can that mount be motorized, with a sensor to give feedback to the ground station. electronics, seem to be, (apologises to EE friends) a dime a dozen, cheaper if made in hundreds, but the key drawback of any design is the mechanical and electromechanical (can we use, mechatronics) system that serves as the actuators. I am not referring to a hand held antenna assembly, but rather something that we can all use in cold/hot weather and that can be put together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu based cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman normanlizeth@gmail.com wrote:
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I think these old articles are really informative. I had collected them earlier, and re-read them just now. BTW Does anyone have any pointers to phase array design tools for satellite antennas as a potential substitute for multi-element yagi ?
73 de X
On Sat, Feb 23, 2013 at 11:03 PM, Samudra Haque samudra.haque@gmail.comwrote:
hi, thanks for addressing this question. And I invite others to participate, or get in touch with me for a phone conversation, and discuss simple steps that can be taken IMHO within 50-100 USD. I suggest we adopt AMSAT friendly tips:
http://www.amsat.org/amsat-new/tools/downloads/iROTOR.pdf (will need additional interface to PC, any kind)
(cool idea, but only as concept) http://www.amsat.org/amsat-new/echo/Az_El_Pos.pdf
http://dgg.gotdns.com/doc/XOX_rotor.pdf (Semi professional..)
http://ka6puw.tripod.com/azimuth1.html <--- what do you think of this style? Looks simple enough.
But I have only done a simple google search here. Any other projects worth investigating? Focus on the "mount" only now.
-samudra
On Sat, Feb 23, 2013 at 10:41 PM, Lizeth Norman normanlizeth@gmail.comwrote:
Samudra, This is a good question for a first year engineering student like myself: How does one bring home the best bang for the buck out of an engineering dollar?
Feel free to ask around. A few on the list have driven unusual devices to get antennas moved.
How does a project get into the hands of people who will actually do it? A one off I can do for you in my basement. Probably with parts from radio shack, a grinder and a few hand tools.. A reproducible project 10 years from now? Hardly likely.
I submit to you that irrespective of the metalwork this is a simple project as you propose, however it must be reproducible. With a student copy of SolidWorks, a circular saw, drill and the Arduino IDE it could be prototyped by two people in a weekend. Refining it so that a relatively new ham with a smidgin of technical ability could do it might take a little longer. These days with the internet and cad, the real issue is the tooling. How do you design/layout such that it can be done with snips/file/saw/fill in the blunt instrument here.. 73 es have fun..
Norm n3ykf
On Sat, Feb 23, 2013 at 10:19 PM, Samudra Haque samudra.haque@gmail.com wrote:
I hope it is evident, I am not focusing on the controller/microcontroller/computer interface/az-el controller/etc. The
real
issue is how cheaply can an antenna be mounted on a kingpost somewhere
on a
surface, with a view towards the sky, and how conveniently can that
mount be
motorized, with a sensor to give feedback to the ground station. electronics, seem to be, (apologises to EE friends) a dime a dozen,
cheaper
if made in hundreds, but the key drawback of any design is the
mechanical
and electromechanical (can we use, mechatronics) system that serves as
the
actuators. I am not referring to a hand held antenna assembly, but
rather
something that we can all use in cold/hot weather and that can be put together by one / two persons on an average post.
Comments welcome, I think the future holds bright for amsats and edu
based
cubesats.
-samudra
On Sat, Feb 23, 2013 at 9:50 PM, Lizeth Norman normanlizeth@gmail.com wrote:
Gus and the group: Lots of birds going up in the next year. Success rate not 100% as it's rocket science oftentimes on a budget. Hopefully we'll get a few out of it. The Arduino IDE install supports PPM. The nice thing about that platform is that configuration is doable for just about all forms of hardware that you might drive with it and scaling can be done in software for the various different bits of kit.
I am sure that with the appropriate development environment and having the hardware on hand IN a well equipped lab, it should be a weekend project to get running.
The hard bit in my opinion is how to mount the antennas to the az/el clockwork. Will require a little woodwork/metalwork to finish.
Everyone who does this will have a problem with some phase of it. Needs to be simple and repeatable.
Norm n3ykf _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the
author.
Not an AMSAT-NA member? Join now to support the amateur satellite
program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hi to all...
I'm involved on a task like these...
Building a super-cheap AL-EL rotator...
I'm in Cuba (FL11ai), No RadioShack or ANY other store for electronics hobbyist... even common pics or LCD screens are rare items here...
Talking with my local hams I have managed to get my hands on a 10 years old surveillance camera made in Japan...
The unit is full waterproof and with more than 10 years in service, it have some age marks on the outside but it's shinny new on the inside... this could be a good start up point...
It have full 360 in azimuth with end switches and only 0-140 degrees on the elevation plane, the local ham who give this item to me use one for move a 7 elements full aluminum Yagui for 2m... for more than 3 years now. (no position system, just visual aim)
I'm thinking in a kind of gray-encoder for position sensing on the rotor to a parallel port of my PC and the software will be my debut on python software (learn python is one of my personal goal this year, and this project is the perfect start...)
just my 5 cents...
73 de CO7WT. Pavel Milanes Costa. FL11ai
El 23/02/13 22:41, Lizeth Norman escribió:
Samudra, This is a good question for a first year engineering student like myself: How does one bring home the best bang for the buck out of an engineering dollar?
A few years back I built the SAEBRETrack system shown here https://sites.google.com/site/marklhammond/saebrtrack. It's based around a BASIC stamp. I built the version used to control the OR-360 rotators but those have become very scarce and worth their weight in gold if you can find them. My point is this though, if you open up an OR-360 you find a surprisingly small "540" DC motor driving the gear train and direction is controlled by voltage polarity. Positioning is by potentiometer feedback. There are probably better ways to do it than a BASIC stamp these days but the concept of driving DC motors to control lightweight arrays has crossed my mind a few times as well. Michael, W4HIJ
On 2/23/2013 9:25 PM, Gus wrote:
Given the shortage of LEO birds, exactly how much antenna do we need to rotate?
Hams operate satellite successfully with hand-held antennas, which have low wind-loading and are light in weight.
With R/C servos available producing 6½ ft. lb of torque for less than 150 bucks, I'm surprised a light weight, portable, DC-operated satellite system complete with antennas and AZ/EL rotors hasn't materialized before now.
On 02/23/2013 07:59 PM, Samudra Haque wrote:
Hi, about two years ago, I started a design for a robotics class project of a AZ-EL rotator controller system, and a hardware package for the mechanism for rotating an antenna in any direction subject to mechanical stops. The system would have been able to handle regular and flip modes. I didn't do anything more than calculations, and moved on to building a classroom instructional robot then.
Lately, as I am setting up (K3GWU, the George Washington University Amateur Radio Club and Research Station) I find that the price of az-el systems such as G5500 + Yaesu AZ-EL rotors are expensive, and are not typically available on an affordable basis on Ebay or eham.net etc. Well, of course, expensive is a relative term, for a student hobby organization, it's a lot, and I guess for small ham operators it is also moderately expensive.
This may be a frequently asked topic: does any one have experienced with (tested) kit designs for AZ-EL rotors that can be made with parts from current suppliers ? I know there are a number of controller designs, but I am interested to know if there are any options for suppliers of the required gears/motors etc.
I have located several large AC motors / DC motors at my university mechanical engineering workshop, but they are not all guaranteed the same specs. I now realize if I do embark on a actual design process with my model/simulation/hardware, it would be nice to build several of these all at once to share the development cost over the production run, and ensure those who want a cheap AZ-EL system can get one. Otherwise the production cost of one heavy duty system is going to be quite high.
I hope some of you may have suggestions for me, both (+) and (-) or perhaps (~) in nature. I thought amsat / amateur radio folks have a common need to encourage homebrew activity to keep their brain cells in working condition?
I'm opening this question up to the national US audience, and welcome any discussion on the challenges of making the ever-so-important azimuth-elevation rotor. I've studied some of the alternatives: Alliance U100 and Yaesu G-5500. I think we can do better in 2013. But ideally, to allow the wide adoption of AMSAT ground stations, what price point would the system have to be to make it worth building ?
73 de N3RDX George Washington University
Hi fellow hams,
Some years ago I have made a complete rotating system based on old and due to battery fail her useless small screwdriver machines, there must be ton off loads from these small machines and with a simple mechanics it is quite easy to make uses off these small but very powerful machines
Vy 73,
PA4PCJ
Hi all! Back in Fl from my trip to the great white north. A bit of trivia. It'll be 30 here overnight. BRRRRR.
An idea that Phil proposed, I've researched and found a possible part. The 9dof imu idea really makes sense. Most of these are stand alone Arduinos in and of themselves. Good example from the near east on the fave rave auction site: 271015460402
The fact that it passes the data over a serial port makes it attractive, as the setup for the device can be done by novices. Note that the data wouldn't be sufficent to pilot an aircraft, but should be perfectly adequate for heading and attitude information to point an antenna.
Having a built in compass makes setup in the field a snap. Just think. Plop the tripod down, turn it on and it will tell where you're pointed. No more gps/compass for finding beam headings.
73 de keep warm Norm n3ykf
participants (8)
-
Greg D -
Gus -
Hans Lourens -
Ing. Pavel Milanes Costa -
Lizeth Norman -
Michael -
Samudra Haque -
Thomas Doyle