Solar Trackign Mount

We have recently upgraded our big satellite dish for one of those small dishes and I was left looking at the mount of the big dish. Is there any information or plans available to convert one of these mounts into a solar tracker? I have checked out the Red Rock Energy site and like the electronic solar tracker hardware there and will probably use the LED solar tracking design for the actual tracking drive, but would like to build mounting hardware to attach four to eight solar panels to the existing octagonal (8-sided) 24" aluminum mounting plate that remains on the post. I do not know enough mechanical engineering to analyze the stresses involved to trust anything that I would try designing. Any help with this project would be greatly appreciated.
Steve Luhn Yet another voice from the middle of the Mojave Desert

"Steven Luhn" wrote in message

We have recently upgraded our big satellite dish for one of those small dishes and I was left looking at the mount of the big dish. Is there any information or plans available to convert one of these mounts into a solar tracker? I have checked out the Red Rock Energy site and like the electronic solar tracker hardware there and will probably use the LED solar tracking design for the actual tracking drive, but would like to build mounting hardware to attach four to eight solar panels to the existing octagonal (8-sided) 24" aluminum mounting plate that remains on the post. I do not know enough mechanical engineering to analyze the stresses involved to trust anything that I would try designing. Any help with this project would be greatly appreciated.
Steve Luhn Yet another voice from the middle of the Mojave Desert

I was scrounging at the dump, and picked up a pole mount for an old ~12' dish. The one I got seems quite rugged to me (all steel), but I mainly picked it up because it has a very nice, long throw linear positioner. My panels are roof mounted, in an almost perfect solar south position, so I probably will discard the mount itself and just use the linear positioner to allow seasonal adjustment of my panels with a simple hinge on the roof. The motor drive was missing, but I also found a drive motor from a rotor antennae that I believe will work with the positiner if I can find the right gear for it.
Now, before I mounted a few thousand dollars worth of panels on a pole I would want to make sure it would stand up to the occasional strong wind gust. I think I' might mount some plywood on there temporarily and wait to see if they were able to withstand a strong wind storm. Unfortunately, that test might take a couple of months to see a good gusty wind storm.
Another possible 'seat of the pants' test might be to try hanging off of one end of the mount, and rocking it back and forth. At 230lbs, if it were able to withstand my weight and some rocking, I'd be pretty confident it would stand up to even a major wind gust. That's not exactly engineering, but it would give me some level of confidence that my panels would not end up in pieces on the ground.
Anyway, that is the "hillbilly engineering" approach I'd take. Overbuild it, and then perform some crude tests to try and feel confident about it's ability to withstand wind and snow loads. Another approach is to have a good look at commercial trackers, copy their designs and overbuild a bit to add a margin of safety for DIY workmanship standards and a lack of mechanical engineering analysis.

On Tue, 06 Dec 2005 03:21:56 GMT, "Steven Luhn" wrote:

We have recently upgraded our big satellite dish for one of those small dishes and I was left looking at the mount of the big dish. Is there any information or plans available to convert one of these mounts into a solar tracker? I have checked out the Red Rock Energy site and like the electronic solar tracker hardware there and will probably use the LED solar tracking design for the actual tracking drive, but would like to build mounting hardware to attach four to eight solar panels to the existing octagonal (8-sided) 24" aluminum mounting plate that remains on the post. I do not know enough mechanical engineering to analyze the stresses involved to trust anything that I would try designing. Any help with this project would be greatly appreciated.
Steve Luhn Yet another voice from the middle of the Mojave Desert

I built one a few years ago from a standard linear-actuator style mount, but ended up abandoning the project. I'd welded up a frame for the modules on the same plane where the dish had been. With a heavy load of (8) 100W modules, I decided that the linear actuator was too iffy. The trouble was the over-center nature of the arrangement, and the crummy leverage from trying to move the array through a large arc with relatively short actuator travel. I didn't trust it, so I bolted a temporary brace in place of the actuator until I could rework the mount. My new plan was to modify a Birdview gear-driven mount so that the pivot point would be vertical. Got busy with other projects though, so I bought a two-axis Wattsun instead. My homemade tracker went to a neighbor who's making good use of it with about half the module weight. Here are some photos that might be useful.
http://www.citlink.net/~wmbjk/images/trackers/wattsunajack.jpg This is an old-style Wattsun. It should give you a good idea of how commercial trackers are constructed. Back then Wattsun used an Ajack gear-driven mechanism, except that it had a vertical pivot where the Ajack dish-mounts had an inclined pivot. There are probably lots of those Ajack dish-mounts around, and they might be the best choice for modification.
http://www.citlink.net/~wmbjk/images/trackers/new%20array.jpg Structure of my homemade tracker.
http://www.citlink.net/~wmbjk/images/trackers/homemadelinear.jpg Closer shot showing details.
Which style of mount would you be starting with, and what size modules do you have?
Wayne

wmbjk wrote in message

On Tue, 06 Dec 2005 03:21:56 GMT, "Steven Luhn" sjluhn@ridgecrest.ca.us> wrote:
We have recently upgraded our big satellite dish for one of those small dishes and I was left looking at the mount of the big dish. Is there any information or plans available to convert one of these mounts into a solar tracker? I have checked out the Red Rock Energy site and like the electronic solar tracker hardware there and will probably use the LED solar tracking design for the actual tracking drive, but would like to build mounting hardware to attach four to eight solar panels to the existing octagonal (8-sided) 24" aluminum mounting plate that remains on the post. I do not know enough mechanical engineering to analyze the stresses involved to trust anything that I would try designing. Any help with this project would be greatly appreciated.
Steve Luhn Yet another voice from the middle of the Mojave Desert
I built one a few years ago from a standard linear-actuator style mount, but ended up abandoning the project. I'd welded up a frame for the modules on the same plane where the dish had been. With a heavy load of (8) 100W modules, I decided that the linear actuator was too iffy. The trouble was the over-center nature of the arrangement, and the crummy leverage from trying to move the array through a large arc with relatively short actuator travel. I didn't trust it, so I bolted a temporary brace in place of the actuator until I could rework the mount. My new plan was to modify a Birdview gear-driven mount so that the pivot point would be vertical. Got busy with other projects though, so I bought a two-axis Wattsun instead. My homemade tracker went to a neighbor who's making good use of it with about half the module weight. Here are some photos that might be useful.
http://www.citlink.net/~wmbjk/images/trackers/wattsunajack.jpg This is an old-style Wattsun. It should give you a good idea of how commercial trackers are constructed. Back then Wattsun used an Ajack gear-driven mechanism, except that it had a vertical pivot where the Ajack dish-mounts had an inclined pivot. There are probably lots of those Ajack dish-mounts around, and they might be the best choice for modification.
http://www.citlink.net/~wmbjk/images/trackers/new%20array.jpg Structure of my homemade tracker.
http://www.citlink.net/~wmbjk/images/trackers/homemadelinear.jpg Closer shot showing details.
Which style of mount would you be starting with, and what size modules do you have?
Wayne

I would be mounting either 8 Arco M-55 panels for a total of 440 watts or a set of 4 Sanyo 165 watt panels for a total of 660 watts. The old dish mount appears to have a 15-20 inch throw arm that the actuator is attached to. I haven't had much of a chance to closely examine the pivot mount yet (dark when I leave for work and dark when I get home), maybe this weekend I can get a closer look. Is there a place I can send pictures if you are interested? Also, I liked the homemade mount. How hard was it to manufacturer?
Steve Luhn (Yet another voice from the middle of the Mojave Desert)

Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.

Steven Luhn wrote:

wmbjk wrote in message
On Tue, 06 Dec 2005 03:21:56 GMT, "Steven Luhn" sjluhn@ridgecrest.ca.us> wrote:
We have recently upgraded our big satellite dish for one of those small dishes and I was left looking at the mount of the big dish. Is there any information or plans available to convert one of these mounts into a
solar
tracker? I have checked out the Red Rock Energy site and like the electronic solar tracker hardware there and will probably use the LED
solar
tracking design for the actual tracking drive, but would like to build mounting hardware to attach four to eight solar panels to the existing octagonal (8-sided) 24" aluminum mounting plate that remains on the post.
I
do not know enough mechanical engineering to analyze the stresses
involved
to trust anything that I would try designing. Any help with this project would be greatly appreciated.
Steve Luhn Yet another voice from the middle of the Mojave Desert
I built one a few years ago from a standard linear-actuator style mount, but ended up abandoning the project. I'd welded up a frame for the modules on the same plane where the dish had been. With a heavy load of (8) 100W modules, I decided that the linear actuator was too iffy. The trouble was the over-center nature of the arrangement, and the crummy leverage from trying to move the array through a large arc with relatively short actuator travel. I didn't trust it, so I bolted a temporary brace in place of the actuator until I could rework the mount. My new plan was to modify a Birdview gear-driven mount so that the pivot point would be vertical. Got busy with other projects though, so I bought a two-axis Wattsun instead. My homemade tracker went to a neighbor who's making good use of it with about half the module weight. Here are some photos that might be useful.
http://www.citlink.net/~wmbjk/images/trackers/wattsunajack.jpg This is an old-style Wattsun. It should give you a good idea of how commercial trackers are constructed. Back then Wattsun used an Ajack gear-driven mechanism, except that it had a vertical pivot where the Ajack dish-mounts had an inclined pivot. There are probably lots of those Ajack dish-mounts around, and they might be the best choice for modification.
http://www.citlink.net/~wmbjk/images/trackers/new%20array.jpg Structure of my homemade tracker.
http://www.citlink.net/~wmbjk/images/trackers/homemadelinear.jpg Closer shot showing details.
Which style of mount would you be starting with, and what size modules do you have?
Wayne
I would be mounting either 8 Arco M-55 panels for a total of 440 watts or a set of 4 Sanyo 165 watt panels for a total of 660 watts. The old dish mount appears to have a 15-20 inch throw arm that the actuator is attached to. I haven't had much of a chance to closely examine the pivot mount yet (dark when I leave for work and dark when I get home), maybe this weekend I can get a closer look. Is there a place I can send pictures if you are interested? Also, I liked the homemade mount. How hard was it to manufacturer?
Steve Luhn (Yet another voice from the middle of the Mojave Desert)

George Ghio wrote:

Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.

Perhaps you could point us to the URL where you've posted your pictures on how you've done it right.

"George Ghio" wrote in message

Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.

Now, if you leave a gap between panels, it would seem that it would let some amount of wind pass through the array. But, wouldn't increase the total width and length of the array, thus increasing the leverage from wind striking the outside edges of the panel and increasing the torque on the center mount.
It is not obvious to me that leaving a gap would be a good idea.

On Fri, 09 Dec 2005 20:26:16 +1100, George Ghio wrote:

Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.

How about some numbers to show how you arrived at that recommendation Mr. "designer".

Bloody amateurs.

What would you call someone who recommended using "300k" wire for alternator field control? Or someone who can't make up his mind if a rheostat is 200A, 150A, or 150 Ohms? Or someone who can't decide if tracking is good for 30% http://tinyurl.com/8bs3j, or 10% http://tinyurl.com/9dx2d ? I'd call him someone who's been bluffing his way through life, and the only thing he's good at is getting caught.
Wayne

On Fri, 09 Dec 2005 03:32:09 GMT, "Steven Luhn" wrote:

I would be mounting either 8 Arco M-55 panels for a total of 440 watts or a set of 4 Sanyo 165 watt panels for a total of 660 watts. The old dish mount appears to have a 15-20 inch throw arm that the actuator is attached to. I haven't had much of a chance to closely examine the pivot mount yet (dark when I leave for work and dark when I get home), maybe this weekend I can get a closer look. Is there a place I can send pictures if you are interested?

Sure, just take the "REMOVE" out of this address wmbjkREMOVE@citlink.net

Also, I liked the homemade mount. How hard was it to manufacturer?

It took about a day to build. It probably would have taken another day to finish and add one of Duane's LED controllers.
Wayne

On Fri, 09 Dec 2005 12:39:21 GMT, "Bughunter" wrote:

"George Ghio" wrote in message Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.
Now, if you leave a gap between panels, it would seem that it would let some amount of wind pass through the array. But, wouldn't increase the total width and length of the array, thus increasing the leverage from wind striking the outside edges of the panel and increasing the torque on the center mount.
It is not obvious to me that leaving a gap would be a good idea.

Yup. And, the mount in question stood up to impressive winds for about a year before I got around to replacing it.
Wayne

On 9 Dec 2005 04:31:27 -0800, "Tony Wesley" wrote:

George Ghio wrote: Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.
Perhaps you could point us to the URL where you've posted your pictures on how you've done it right.

Don't hold your breath. It would be a bit difficult for a "professional" tracker builder who's "never seen a working tracker" to post photos of his successes. :-)
Wayne

Industry standard practice. Space between the panels reduces wind loading. Fact.
Tony Wesley wrote:

George Ghio wrote:
Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.
Perhaps you could point us to the URL where you've posted your pictures on how you've done it right.

Bughunter wrote:

"George Ghio" wrote in message
Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.


Now, if you leave a gap between panels, it would seem that it would let some amount of wind pass through the array. But, wouldn't increase the total width and length of the array, thus increasing the leverage from wind striking the outside edges of the panel and increasing the torque on the center mount.
It is not obvious to me that leaving a gap would be a good idea.
Obvious to you or not, it works. You can do it or not. It's up to the

user. I have seen many ways to handle the problem from leaving a single large hole in the center of the array to gaps between all the panels.
Yes you could view it as increasing the leverage. But it is not worth worrying about when you are also reducing the load at the outside edges.
All information from NGs is at your own risk. Now you can listen to Wayne and maximize the load on your tracker and if it blows over it's your problem.
OTOH
You can listen to me and reduce the load on your tracker and if it blows over the problem is still yours.
Make a choice, higher loading or reduced loading.
My advice is industry standard practice.

George Ghio wrote:

Industry standard practice. Space between the panels reduces wind loading. Fact.

I didn't ask that.
So you have no URL, nor examples of how you've done it.

George Ghio wrote:
Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.

Speaking of amateurs, how's that spreadsheet coming?

On Sat, 10 Dec 2005 09:32:50 +1100, George Ghio wrote:

Tony Wesley wrote: George Ghio wrote:
Note the excellent photos of how to maximise wind loading on a tracker.
Suggest that a minimum gap of 100mm be left between mounted panels.
Bloody amateurs.
Perhaps you could point us to the URL where you've posted your pictures on how you've done it right.
Industry standard practice. Space between the panels reduces wind loading. Fact.

Where is the proof of this supposed fact? All I see is another of your silly rules of thumb.
Here are some photos -
Wattsun single-axis tracker, factory drilled for Solarex modules. Approximately 11/16" inch spacing. Successfully in service at a high wind site for ten years http://www.citlink.net/~wmbjk/images/trackers/solarexspacing.jpg
Wattsun two-axis tracker, factory drilled for Photowatt modules. Approximately 1/2" spacing vertical, 1/4" horizontal http://www.citlink.net/~wmbjk/images/trackers/photowattspacing.jpg
Wayne