Strut channel for roof of RV

Zwy

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If the galvanized unistrut doesn't rust, why would you have rust stains on the RV? I definitely don't want that eithe

How is everybody attaching the solar panels to the unistrut? I like the idea of THESE with spring nuts.

I will be mounting most, if not all, of my panels on my RV parallel to the unistrut, and i think I will just laser cut 12ga stainless steel brackets that bolt to the unistrut and to the panel. But on the metal building next to me, I will be mounting all the panels perpendicular to the unistrut, and using those Clamps linked above would be perfect.
I used some of those in between panels https://www.amazon.com/gp/product/B07YGYMPLB/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 You will need to use the right screw head for those or use a stainless washer on top if you prefer hex head. I ordered some socket head bolts in 1/4" stainless, those ended up being slightly small on head size, ended up using some stainless 1/4" bolts bought at a big box lumber yard with phillips button head. I also used Eternabond double sided tape where each lag bolt hole went thru the roof followed by Dicor on the side of the Unistrut where the tape is to keep dirt from sticking to the Eternabond and covered Unistrut roof lag bolt heads with Dicor. I expect no leaks, Eternabond double sided is not fun to work with. If you have TPO roof, be sure to use the primer, I tape off the spot as I don't want the overspray outside the tape mounting area.

Several choices on the ends, I ended up just fabbing a bracket from aluminum angle but that required drilling thru the side of the panel frame. I didn't really have a choice, space constraints. These would work or something similar. https://www.amazon.com/UI-AI-Solar-...T2KPV8X6T4Y&psc=1&refRID=BPGWQTCWKT2KPV8X6T4Y

Now, if you want some tilting panels, well, that's a different story. I have one panel on each side of the roof air and as one would be most likely shaded during the day. I fabbed my own mechanism for the electric actuator that slides a pin automatically in the retracted position to lock the panels down for travel. Killed many hours doing it. Had to fab my own hinges and mounts too, good thing I have a TIG welder. If you want to buy something, Kevin Means either is making and installing these or sold the design to someone and they make them. https://www.rvforum.net/threads/tilting-solar-panels.96179/ And the product is Solar Vector. https://www.solarvector.net/ those are not cheap however and how they mount them on an RV is a joke using expanding nuts.

But the best design I've seen for tilting in both directions for max output was on FB by Gene Morris in the Solar Powered RV group. Has to be heavy though. Had 2400w of panels, " Total solar output went from 25% on a perfect day to 65% on a warmer, high haze, sunny day!"

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Boondock Saint

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If you want to buy something, Kevin Means either is making and installing these or sold the design to someone and they make them. https://www.rvforum.net/threads/tilting-solar-panels.96179/ And the product is Solar Vector. https://www.solarvector.net/ those are not cheap however and how they mount them on an RV is a joke using expanding nuts.
I'm real real familiar with his work. I spent some time last year working an an RV rooftop auto tracking system with sensors and actuators. I have a good design, but my roof doesn't have the space to implement it for each panel. I'll probably just just one way auto actuation instead and change the direction of my rig accordingly. Much easier and cheaper.
 

Lt.Dan

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I'm real real familiar with his work. I spent some time last year working an an RV rooftop auto tracking system with sensors and actuators. I have a good design, but my roof doesn't have the space to implement it for each panel. I'll probably just just one way auto actuation instead and change the direction of my rig accordingly. Much easier and cheaper.
More info/pics? I finished mine but I always like to think... 🤔
 

Zwy

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I'm real real familiar with his work. I spent some time last year working an an RV rooftop auto tracking system with sensors and actuators. I have a good design, but my roof doesn't have the space to implement it for each panel. I'll probably just just one way auto actuation instead and change the direction of my rig accordingly. Much easier and cheaper.
I never quite understood why he uses a V for the locking rods.

If I had a motorhome or large 5th wheel, I'd opt for the racking in the photo above. He had the results for increased charge amps from the change from all flat panels, quite amazing the increase, it was more than 35%. He most likely was dealing with some shading issues.
 

Lt.Dan

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I never quite understood why he uses a V for the locking rods.

If I had a motorhome or large 5th wheel, I'd opt for the racking in the photo above. He had the results for increased charge amps from the change from all flat panels, quite amazing the increase, it was more than 35%. He most likely was dealing with some shading issues.
That is awful nice on that Momentum too, I thought about doing that exact thing after you posted it, but I was worried and didn't want the extra work. I also figured I couldn't fit and more panels so I ended up just laying them flat with unistrut.

20210410_120900.jpg
 

Zwy

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More info/pics? I finished mine but I always like to think... 🤔
Saw this one a few months back. I'll just watch my meter for most amps, then check it now and then.

This is the best tracker video I ever saw though, simple in design.
 

Zwy

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That is awful nice on that Momentum too, I thought about doing that exact thing after you posted it, but I was worried and didn't want the extra work. I also figured I couldn't fit and more panels so I ended up just laying them flat with unistrut.

View attachment 47623
If you have the room, laying the panels flat is the way to go, just install more panels. It is when shading affects charging amps enough when the battery can't be fully charged thru the day that one should look at tilting. I knew mine would be shaded and affect output. I only have limited space on the truck camper.
 

Boondock Saint

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I have every auto tracking and prototype published, every video etc bookmarked. I had a design in my head, and then looked at what others did. Mine is a best of the best of them, but as I stated, I just don't have the room and wherewithal to implement it given the way I need to place my panels.

Tracking up and down as the sun rises and sets is fine with me, I can adjust the angle of my rig to accommodate for the sun moving across the sky during the day. A slight change in direction via the steering wheel is a hella lot easier than climbing the roof! I can live with a one way tilt.

Anyhoo - I like the idea of some uni-strut to give the most anchoring along the roof possible.
 
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K8MEJ

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Here's what I did. I have eight Rich Solar 200 watt, 24 volt panels. Next year I will replace the rooftop A/C with something more efficient. Once I do that, I can fit two more panels on the roof. I could do it w/o replacing the A/C, but that would make it difficult to walk on the roof.

I ended up using aluminum unistrut, stainless steel sping nuts, and EcoWorthy aluminum tilt mounts. I don't think I'll be tilting panels very often, but it's very nice being able to easily tilt them for maintenance, wiring, etc.

In full sun, I get about 1200 watts out of the 1600 watts.
IMG_5382.jpegIMG_5387.jpegIMG_5386.jpeg
 

GSXR1000

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I've decided to use low-profile (13/16") strut channel for the roof of my travel trailer upon which I will mount tilt brackets and 200 watt Rich solar panels. The tilt brackets might not be used often for tilting the panels toward the sun, but will allow me to raise the panels for maintenance or allow me to tilt them up and out of the way if I want to take the shrouds off the A/C units, fans, etc.

Aluminum strut channel would be nice for weight savings and corrosion resistance. However, it's not easy to find and will likely have to be ordered from an industrial or electrical supplier. And it's more expensive. An alternative is the gold tone galvanized steel strut. It's readily available and less expensive, but will weigh more. I don't live near the ocean, but I'm concerned about using the galvanized strut on the roof of a camper that is not stored inside. I could paint it for an extra level of protection, but I don't know about the longevity.

Should I pony up the cash and order aluminum strut channel or will the higher quality electro-galvanized stuff work well enough for this application?

Thanks!
I put 1x4 down first but I had a new roof sprayed on first
Screenshot_20210424-202323_Gallery.jpg
 
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Boondock Saint

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Here's what I did. I

I ended up using aluminum unistrut, stainless steel sping nuts, and EcoWorthy aluminum tilt mounts.
@ K8MEJ - I really want / need those parts numbers and where you bought / ordered from! Thanks in advance.
 

K8MEJ

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  • 13/16" x 10' aluminum Unistrut - Grainger (shop around local electrical supply shops and you can probably find it cheaper.
  • Stainless steel spring nuts - another person on this forum suggested them - eBay link
  • Aluminum tilt mounts from Eco-Worthy - link here - these are generic and sold by Rich Solar and others but Eco-Worthy was the cheapest I found
I used SS 1/4-20 x 3/4" long screws and lock washers to attach the brackets to the Unistrut spring nut.

I used SS 1/4-20 x 1.5" long SS lag screws and 1.5" fender washers per Lt. Dan's recommendation to fasten the Unistrut to the roof. Frankly, you don't need that long and make sure you match the length to your needs on your roof.

I put 3" long pieces of butyl tape under each slot in the Unistrut where I lag screwed it to the roof. I used Dicor self-leveling sealant over the screw heads and washers. That gave me a slight gap under the Unistrut for water to run down the crown of the roof under the Unistrut in a number of places.

I also bought some 1/6" SS airplane cable and clamps so I can make some safety tethers in the unlikely event a panel comes loose. This will scratch the hell out of the side of my camper but it should prevent a loose panel from sailing into someone's windshield. I do this at the recommendation of @Will Prowse .

I hope that helps.
 

Boondock Saint

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Yeah thanks so much for your exacting reply! I saw the SS suggestion before but it's great to have a compendium of parts in one thread, thanks again.
 

Tball

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  • 13/16" x 10' aluminum Unistrut - Grainger (shop around local electrical supply shops and you can probably find it cheaper.
  • Stainless steel spring nuts - another person on this forum suggested them - eBay link
  • Aluminum tilt mounts from Eco-Worthy - link here - these are generic and sold by Rich Solar and others but Eco-Worthy was the cheapest I found
I used SS 1/4-20 x 3/4" long screws and lock washers to attach the brackets to the Unistrut spring nut.

I used SS 1/4-20 x 1.5" long SS lag screws and 1.5" fender washers per Lt. Dan's recommendation to fasten the Unistrut to the roof. Frankly, you don't need that long and make sure you match the length to your needs on your roof.

I put 3" long pieces of butyl tape under each slot in the Unistrut where I lag screwed it to the roof. I used Dicor self-leveling sealant over the screw heads and washers. That gave me a slight gap under the Unistrut for water to run down the crown of the roof under the Unistrut in a number of places.

I also bought some 1/6" SS airplane cable and clamps so I can make some safety tethers in the unlikely event a panel comes loose. This will scratch the hell out of the side of my camper but it should prevent a loose panel from sailing into someone's windshield. I do this at the recommendation of @Will Prowse .

I hope that helps.
What are the spring nuts used for? I don't see them in any of your photos, thanks!
 

Zwy

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What are the spring nuts used for? I don't see them in any of your photos, thanks!
That is what the fastener screws into. The nut is spring loaded to hold it against the top of the channel. Lets say your unistrut is 10 feet long and you want a place to fasten a solar panel in the middle at 5 feet. You take the spring loaded nut and push it into the channel, turn it 90 degrees and the spring will hold the nut up so you can thread the fastener into it. A non spring nut would lay at the bottom of the channel and you would need a long fastener to reach it.
 

Tball

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That is what the fastener screws into. The nut is spring loaded to hold it against the top of the channel. Lets say your unistrut is 10 feet long and you want a place to fasten a solar panel in the middle at 5 feet. You take the spring loaded nut and push it into the channel, turn it 90 degrees and the spring will hold the nut up so you can thread the fastener into it. A non spring nut would lay at the bottom of the channel and you would need a long fastener to reach it.
Makes sense! I was scratching my head LOL thinking that the nutplate was in a groove that held it in the channel but this sounds pretty easy too. Thanks for explaining!
 
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eXodus

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RV manufacturers have to think about how to get all that obstructions of the roof.
Newer panels are better in capturing from various angles. Just need to make the whole roof usable.

Need to figure out how to remove the A/C, get the vents under to open under the panels. There are lots of unnecessary penetrations on the roof.
 

Lt.Dan

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RV manufacturers have to think about how to get all that obstructions of the roof.
Newer panels are better in capturing from various angles. Just need to make the whole roof usable.

Need to figure out how to remove the A/C, get the vents under to open under the panels. There are lots of unnecessary penetrations on the roof.
My God there's so much unnecessary i can't stand it
 
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