need help on solar ground mount

[Kaizen]

I am doing ground mount solar panels on one side of my yard. I wanted to try to make an adjustable single mount 6 panel set up with steel I had on hand and now have a bending issue. I used 1.5" 1/8 wall tube with a center pivot on the post as shown in picture. I used factory made aluminum rails bolted to these to secure the panels. I ran a string line after loading the 6 panels and have too much deflection to be comfortable with. I have a front stabilizer bar running from the front to the center post to keep it all from moving as it is perfectly balanced and swings easily to change for the seasons.
I can jack it straight and weld something to the bottom or the side OR I can try and make an upside down truss of some sort. these end bars are 12' long and i'm wondering if any one with more structural experience can make a suggestion. How far out to go....what size....etc?
Or any other ideas would be great.

 

[GeoBruin]

If you're set on using the 1.5" tubing, you'll have to stiffen it somehow. A truss is a cool idea but probably not necessary. I was going to suggest skip welding a piece of flat bar to the bottom of the member, but I realize you've bolted through it. How about welding a piece a angle iron to the back of it so you can still bolt through it, but it adds some stiffness?

 

[kbeefy]

I like the idea of a truss under it. I have no practical experience with it but it sounds good.

 

[jeepxj]

OOo fun.

hang on a minute

 

[jeepxj]

6" height in the middle. taper down. critically move the pivot point to the bottom putting the top member into tension.

 

[Kaizen]

6" height in the middle. taper down. critically move the pivot point to the bottom putting the top member into tension.

Beautiful. The pivot point was what i was worried about. Too much weight to move safely at this point so i'd have to take it all apart. Not sure i could fab this up in the air. I appreaicate the help and viaualization.

 

[Kaizen]

If you're set on using the 1.5" tubing, you'll have to stiffen it somehow. A truss is a cool idea but probably not necessary. I was going to suggest skip welding a piece of flat bar to the bottom of the member, but I realize you've bolted through it. How about welding a piece a angle iron to the back of it so you can still bolt through it, but it adds some stiffness?

I was eying my scrap angle pile with this thought. I would need to go to the metal store and if i'm doing that maybe just get the 2.5" tube and do it right. arghhhh. Angle sure would give it 2x more stiffness. gotta ponder. ty

 

[jeepxj]

Beautiful. The pivot point was what i was worried about. Too much weight to move safely at this point so i'd have to take it all apart. Not sure i could fab this up in the air. I appreaicate the help and viaualization.

no you'll need to pull it down.

if you want to fab in the air i'd prefab the truss on the ground then use some bolted connections at the end to be able to bolt it up before welding while pre tensioning/pushing straight the main spar

 

[jeepxj]

I was eying my scrap angle pile with this thought. I would need to go to the metal store and if i'm doing that maybe just get the 2.5" tube and do it right. arghhhh. Angle sure would give it 2x more stiffness. gotta ponder. ty

You could just slap another 1.5" box tube you seem to have plenty of on the bottom after you straighten the top piece out. giving you a 1.5 x 3" effective tube.

 

[Kaizen]

You could just slap another 1.5" box tube you seem to have plenty of on the bottom after you straighten the top piece out. giving you a 1.5 x 3" effective tube.

Yea definitely would give it the needed strength. Should have just bought 2x4 tube and saved myself the trouble. Thanks for the guidance.

 

[jeepxj]

Yea definitely would give it the needed strength. Should have just bought 2x4 tube and saved myself the trouble. Thanks for the guidance.

if you listen to GJ you end up with:

 

[larry_g]

I am doing ground mount solar panels on one side of my yard. I wanted to try to make an adjustable single mount 6 panel set up with steel I had on hand and now have a bending issue. I used 1.5" 1/8 wall tube with a center pivot on the post as shown in picture. I used factory made aluminum rails bolted to these to secure the panels. I ran a string line after loading the 6 panels and have too much deflection to be comfortable with. I have a front stabilizer bar running from the front to the center post to keep it all from moving as it is perfectly balanced and swings easily to change for the seasons.
I can jack it straight and weld something to the bottom or the side OR I can try and make an upside down truss of some sort. these end bars are 12' long and i'm wondering if any one with more structural experience can make a suggestion. How far out to go....what size....etc?
Or any other ideas would be great.

in my minds eye you could fabricate something like this that would have a U channel on below the pivot to support the tube for a foot or so between the two mounting bolts for the panels. I'm assuming that most of the bending is happening where the tube is weakened by the drilled pivot hole.

 

[GeoBruin]

if you listen to GJ you end up with:

Seems like a very inefficient beam. I wonder what that was for.

 

[jeepxj]

Seems like a very inefficient beam. I wonder what that was for.

vertical load

 

[Kaizen]

in my minds eye you could fabricate something like this that would have a U channel on below the pivot to support the tube for a foot or so between the two mounting bolts for the panels. I'm assuming that most of the bending is happening where the tube is weakened by the drilled pivot hole.

That would be a nice seasonal adjustment bracket. At 12 feet long my guess i'd need support for at least the middle six feet. Think its just too much of a load. Of course the 3/4 hole didnt help the situation but its an even bend the whole way. I might add something like this regardless to strenthen that hole. in hindsight that was a dumb move.