24' Enclosed Trailer Build

[Lt.Dan]

Moving on to a new thread with my planning.

Solar Cargo Trailer Built - System Check Please

Currently planning a 7x14 or 7x16 Trailer - for towing behind my Class A RV to move to a new property. There we are going to built a small house. During construction this trailer should also server as base of operations to support the whole thing. Storing tools. Washing machine. Etc...

diysolarforum.com

Sorry for side railing yours Dan.

No worries, I'll come derail yours next ?

 

[eXodus]

Got some more progress done, check it out!

did you space the strut channels of the roof or did you seal them?

I'm planning something similar and wonder if I should leave a gap underneath for water to drain - or just seal it up and let the water run to the front or back.

BTW I got my new trailer standing in my driveway. 7x14. Should fit 4x480W panels perfectly on the roof.

 

[Lt.Dan]

did you space the strut channels of the roof or did you seal them?

I'm planning something similar and wonder if I should leave a gap underneath for water to drain - or just seal it up and let the water run to the front or back.

BTW I got my new trailer standing in my driveway. 7x14. Should fit 4x480W panels perfectly on the roof.

I learned the hard way on my Momentum 5th wheel that I should have spaced the unistrut up to allow water to run out. For the enclosed, I cut 1/4" Stainless Steel washers on the laser to give it some space, then used dycor in the hole to seal it up.

Cant wait to see it!

 

[OffGridForGood]

I wish I had a laser to cut washers...!

 

[Lt.Dan]

I wish I had a laser to cut washers...!

it definitely has its perks!

 

[eXodus]

For the enclosed, I cut 1/4" Stainless Steel washers on the laser to give it some space, then used dycor in the hole to seal it up.

I don't have a laser cutter, but I have a 3D-printer with all sorts of materials.

PETG is very strong under compression (70-100 MPa) and pretty UV resistant - under the panel it would not see much daylight anyhow - but still, when sealed up and covered by Dicor the print should last indefinite.

Before the 3D-print would collapse - the bolt would rip out the flimsy trailer steel

I learned the hard way on my Momentum 5th

what was the issue there?

 

[Lt.Dan]

what was the issue there?

The roof on the 5th wheel wasnt perfectly flat (length wise), so water would pool in some spots. It was almost just a little wavy. Even though the roof was curve so water would run off the side, the unistrut would hold it in. Then the unistrut would rust a tiny bit and stain the white PTO roof.

 

[eXodus]

The roof on the 5th wheel wasnt perfectly flat (length wise), so water would pool in some spots. It was almost just a little wavy. Even though the roof was curve so water would run off the side, the unistrut would hold it in. Then the unistrut would rust a tiny bit and stain the white PTO roof.

thanks, ok then it's decided, will space the struts to allow water to drain:

SuperMag 3/8 in. Square Strut Washer Silver Galvanized with Magnets (5-Pack) - Strut Fitting ZAB2413/8MEG - The Home Depot

The SuperMag 3/8 in. Square Washer is made of SilverGalv steel with magnets and can be used with Superstrut metal framing. This fitting adds convenience and safety to strut assembly by eliminating the

www.homedepot.com

Going to take a look at those 1/4 thick strut washers sometime this weekend and see if their coating looks trustworthy.

 

[eXodus]

Got some more progress done, check it out!

Hey i am currently mounting my panels and wanted to ask what torque values you used on the mid-clamp on the Unistrut?

And which mid clamps?

Mine start slightly bending when I use the 15NM the panel manufacturer recommends.

 

[Lt.Dan]

Hey i am currently mounting my panels and wanted to ask what torque values you used on the mid-clamp on the Unistrut?

And which mid clamps?

Mine start slightly bending when I use the 15NM the panel manufacturer recommends.

These are the ones I used: https://a.co/d/eE67UZZ

I also just sent it with a 3/8" impact, my guess would be somewhere around 40-60ft/lbs. Probably way tighter than they were supposed to be lol, but no bending.

 

[eXodus]

These are the ones I used: https://a.co/d/eE67UZZ

I also just sent it with a 3/8" impact, my guess would be somewhere around 40-60ft/lbs. Probably way tighter than they were supposed to be lol, but no bending.

I would assume M8 stainless steel screws? You remember the length? 50mm ?

I used those: https://a.co/d/dB6VXps and some of them are bending. Not all of them. Might be just cheap material. Not 100% trusting those.

 

[eXodus]

These are the ones I used: https://a.co/d/eE67UZZ

I like those much more. Solid hunk of metal and a skinnier.

 

[Lt.Dan]

I would assume M8 stainless steel screws? You remember the length? 50mm ?

I used those: https://a.co/d/dB6VXps and some of them are bending. Not all of them. Might be just cheap material. Not 100% trusting those.

I actually drilled them out and used 3/8" Grade 8 hardware. Only because I had a huge box of 3/8" Spring Nuts for the Unistrut.

 

[eXodus]

You are even more overkill with your construction then I am I found M8 stainless steel spring nuts for the struts.

But yeah, the bolt won't be the part which will fail in this construction. More likely the unistrut bends and opens up.

 

[Lt.Dan]

You are even more overkill with your construction then I am I found M8 stainless steel spring nuts for the struts.

But yeah, the bolt won't be the part which will fail in this construction. More likely the unistrut bends and opens up.

I plan for the roof to come off the trailer before the solar panels go anywhere lol

 

[eXodus]

I plan for the roof to come off the trailer before the solar panels go anywhere lol

Yeah the weak point is probably the trailer roof rails to the walls. But those are welded, and are many. I think we should see a broken weld before the whole thing comes of.
I bolted M8 through the roof trusses and put locking nuts underneath - so impossible to pull out. I think you drilled and put screws from above ?


Your panels are resting directly on the Unistrut? I saw some people adding a small spacer there in between?
I used those: https://a.co/d/7oJXDVN to space my strut from the trailer roof. So water can drain underneath.

 

[Lt.Dan]

Yeah the weak point is probably the trailer roof rails to the walls. But those are welded, and are many. I think we should see a broken weld before the whole thing comes of.
I bolted M8 through the roof trusses and put locking nuts underneath - so impossible to pull out. I think you drilled and put screws from above ?


Your panels are resting directly on the Unistrut? I saw some people adding a small spacer there in between?
I used those: https://a.co/d/7oJXDVN to space my strut from the trailer roof. So water can drain underneath.

Yes, they would have to break the welds from the uprights to the roof line on mine. I was able to get some pics of when they were building mine.


I wanted to run bolts all the way through and put nuts on the inside, but I also opted for the insulation package and full vinyl walls inside. I didn't want to ruin the vinyl ceiling, so I just opted for some very large 1/4" Self Tappers into each 1.5" Square Tube rail, which was quite a few. I then laser cut some 1/4" thick Stainless steel washers to space the unistrut off the roof and allow drainage etc. I also did lay the panel directly on Unistrut, and used the clamps to hold them down. Is there any reason for the insulated spacer?



You can see the trim piece down the center of the roof that overlaps the 2x sheets is already sagging. The screws they used literally pulled through the material so nothing is holding it up except the silicone. This picture is from a few months ago, and it is getting worse. I am thinking about using some 1/8" Aluminum instead of this crap 1/4" fiberboard they used.

 

[eXodus]

Is there any reason for the insulated spacer?

SLR200SA-KIT Unistrut Solar End Clamp For Strut Based Racking System (Includes High Wind Clamp)

Unistrut Solar End Clamp For Strut Based Racking System (Includes High Wind Clamp)

www.kellyhayes.com

https://cdn.shopify.com/s/files/1/0614/5546/6701/files/PVKit2-Brochure-05212018.pdf?v=1686620738

it's apparently either for high wind load (not sure if a flat mounted panel with no back pressure is considered - high wind) or bonding purposes.

 

[eXodus]

These are the ones I used: https://a.co/d/eE67UZZ

I also just sent it with a 3/8" impact, my guess would be somewhere around 40-60ft/lbs. Probably way tighter than they were supposed to be lol, but no bending.

I just replaced my clamps with the ones you suggested.

Much better solution. Half of the clamps I used where bending. So would probably come loose eventually.