Economical way for under-rack solar panel slide-out?

[jeegro]

I have a front runner rack and my eyes are on a Renogy 150w panel (40x40"). I think the best way is for it to mount under rack, and slide out the back. I also have a barn door & rear table, so this will double as an awning!

40" drawer slides are usually rated for 500+lbs and cost $200+. Does anyone have clever ways to accomplish the slide out? I thought about using aluminum u-channel, but then there would be nothing to support the panel when extended.

 

[ludeykrus]

In for ideas. I've been looking at ways to do something similar with two Renogy 100W panels to slide out the sides of a bed rack. Best bet I've seen so far is stainless-steel heavy duty cabinet sliders (I think from Home Depot) mounted on the bottom of the rack.

EDIT - This is the thread I saved from elsewhere going over the idea:
https://forum.ih8mud.com/threads/solar-panel-mount.811312/

 

[rayra]

panel doesn't need much of any support. They don't weigh much and are semi-rigid already. You could nest C-channel, piece on the panel, piece under the rack. Or simple mount the panel to a thin backer panel, wood, plastic or metal.
sure as hell doesn't need heavy duty / expensive sliders.
I'd suggest jus tmounting the panel to a slightly wider and much longer piece of plywood, so the panel would be slid out far enough to not be shaded by the vehicle. Otherwise it probably won't function properly anyway. Would be a bit like a diving board. And could be used to attach a shade awning, lean-to, bug netting, hanging lamp etc etc


I posted some sketches about a similar idea some time ago, but had to give it up for my Suburban as there wasn't room on the sides between the rack footings. Winding up going with a folding / portable panel that I can both mount on the roof deck and set on the ground with a long lead.

http://forum.expeditionportal.com/threads/144932-Looking-for-vehicle-solar-panel-roof-mount-ideas

Some real nice roof mount ideas got posted in that topic.

 

[jeegro]

That's a cool setup. I used to live in vancouver for 6 years.

So you went with drawer slides... that makes sense for only 1 panel because there are plenty of cheap slides in 24" length. I actually just bought 2x 100 renogy panels, and plan to put them in sideways so they roll out the back. That means I need about 40" of sliding power.

rayra, thanks for the link. I will comb through it. So if I put the panels on perhaps a 50" length of aluminum, is that enough? Remember I have 2 panels, 30 pounds total. I think I need to frame it, which means aluminum square tube instead of u-channel in order to put a support beam in the forward section to stabilize the 10" of empty space.

I also want to have a pin locking mechanism, at half length (1 panel) and full length (2 panels) mounted to the end of the rack. Ideally locking (with key). I went through mcmaster catalog and can't find anything that fits. Ideas?

 

[JCDriller]

That's a cool setup. I used to live in vancouver for 6 years.

So you went with drawer slides... that makes sense for only 1 panel because there are plenty of cheap slides in 24" length. I actually just bought 2x 100 renogy panels, and plan to put them in sideways so they roll out the back. That means I need about 40" of sliding power.

rayra, thanks for the link. I will comb through it. So if I put the panels on perhaps a 50" length of aluminum, is that enough? Remember I have 2 panels, 30 pounds total. I think I need to frame it, which means aluminum square tube instead of u-channel in order to put a support beam in the forward section to stabilize the 10" of empty space.

I also want to have a pin locking mechanism, at half length (1 panel) and full length (2 panels) mounted to the end of the rack. Ideally locking (with key). I went through mcmaster catalog and can't find anything that fits. Ideas?

I've been thinking about this same idea, but planned on it coming out over the hood so when parked in populated areas people would be less likely to screw with it. I do like your idea of using it for an awning, but that wouldn't work for the 4runner.

 

[jeegro]

This might work for the hold open or closed mechanism. No lock though.

https://www.mcmaster.com/#1436a2/=188w76y

 

[jeegro]

I think the way to go is something called t-slot framing aka 80/20 track using linear motion bearings. However the only design I can come up with so far requires 2x height, i.e. top fixed t-slot bar, and the panels framed to another t-slot bar that slides along the bottom of the fixed bar. Cost wise it would be probably as much as HD drawer slides...

 

[rayra]

Depends how fancy you want to get. Some sort of spring-loaded pin would work. So would a simple series of holes and a cotter pin or split ring or a link pin. You could even use a small padlock and get both location fixing and theft-proofing in the same go.

If you have vertical room, you could hinge the two panels to each other on the long side, mount the sandwich on the sliding tray, slide it out and unfold the panels.

Problem with a fixed mounting system is it might not align right with your parking position or location. Then you don't get much if any power out of the panels. I'd consider your sliding mount more of a storage solution and rig the panels so they can be erected at a proper angle atop the vehicle rack or on the ground, somewhere in full sun.

The other deal is having your roof mounted panel positioned and exposed such that even in the stored position it is passively feeding power to your battery. Elsewise why have it.


You might do better to get this topic moved to the 12v forum, lot more solar panel experience in there.

 

[jeegro]

You're right rayra... moved to solar section.

I spent an hour talking with the guys from 8020.net. This stuff looks very promising, simple, and cheap.

Basically these two components

Rails: https://8020.net/shop/1515-uls-black.html
Glide track: https://8020.net/shop/2051.html
plus applicable fasteners and brackets (TBD)

There will be two fixed ~48" rails (8" longer than the panels) mounted lengthwise underneath the rack. The frontrunner rack actually uses very similar, if not identical style tracks to 80/20.
The two panels will be framed in 80/20 rails above. The front of the solar panel (deepest part, forward of car) will have two fixed mounted glide tracks on the rail (on either side)
The rails fixed to the rack will have 2 glide rails at the very back.

The only downside is that the front and back glide rails will act as a stop against each other, preventing the panels from being detached and put elsewhere whereever the sun is. On the bonus side, it stops the panels from flying out the back

I do expect some trickle amps to come in when stowed away. Honestly, I don't want to do much more work than just sliding it out. Tracking the sun, moving them around... not for me. I could say I'll do it, but I'll never end up actually doing it. I did fabricate an Anderson power pole switch plate inside the car that I can easily plug up to 3 other panels in.. so maybe a suitcase panel plus this fixed panel would be a good combo.

 

[JCDriller]

The only downside is that the front and back glide rails will act as a stop against each other, preventing the panels from being detached and put elsewhere whereever the sun is. On the bonus side, it stops the panels from flying out the back

Could you put a retractable latch on the front of the rack so they could be slide out the front when you want to move them around?

Great idea by the way, looking forward to seeing what kind of amps or milliamps you pull with when the panels are stowed and 75% shaded.

 

[jeegro]

View attachment 407149
Fwiw, you could attach those 'glides direct to your solarmodule, perhaps a thinner aluminum profile what your module is then attached to.
Could save about 2" overall width between slider rails. And save a few bucks worth T-slot.

Yes, I might need to. The last measurement I took allows for 44" width. 40.8" for the panel, and 4x1.5" for the t-slot. Uh oh. It looks like they also make .75" wide t-slot, but I'm still short 1.3"... Hmm.

However, with 2x 40x20" panels, I need to frame them together somehow, with the rails being 4-8" longer than the panels so that it can travel out far enough and have support

 

[jeegro]

View attachment 407149
Fwiw, you could attach those 'glides direct to your solarmodule, perhaps a thinner aluminum profile what your module is then attached to.
Could save about 2" overall width between slider rails. And save a few bucks worth T-slot.

The solar panels actually have to be framed in the t-slot, because the glides that attach to the roof rack mounted track have to be fixed mounted to the roof rack track, otherwise the solar panel frame would just slide out of the track. Which means the solar panels have to also have t-slot track. Here's a mockup I made:

The overall width of the proposed mount is 47.19". My rack is that wide, however the 4 rear feet that attach the rack to the truck only allow for 45" of width. The feet bracket are about 1/4" tall. The idea I have is to machine u-shaped slots/notches out of the track so that the t-slot can mount flush to the bottom of the rack, over the feet.

 

[Scoutn79]

Personally I am a fan of couple "C" channel or "L" angle mounted under the rack where the panel is just sild in place. A few well placed rubber wedges to keep it from rattling and a latch system of your choice. I don't like a permanent mount set-up because I like to park the truck in the shade if I can and run wires from the panel. Cheap easy and adaptable to different situations/conditions.

Darrell

 

[jeegro]

Personally I am a fan of couple "C" channel or "L" angle mounted under the rack where the panel is just sild in place. A few well placed rubber wedges to keep it from rattling and a latch system of your choice. I don't like a permanent mount set-up because I like to park the truck in the shade if I can and run wires from the panel. Cheap easy and adaptable to different situations/conditions.

Darrell

Yeah, it's a good point. It would be nice to have that flexibility... leave it on the rack extended, or pull it out and set it up elsewhere. I could instead frame the two panels in aluminum angle or square tube (leaning towards the tube because it's easier to build a frame), and then affix a 48" cut to length glide track:


That way the whole thing could slide out, AND I could make it fit in between the 45" I have. And no rattling. I think it would need some sort of prop though when fully extended to support the weight.

 

[Hillbilly Heaven]

I like the UHMW slides but am concerned if used in a way that allows you to completely remove the panel, that it might prove difficult or awkward to slide them back in by just one person.

If you are going to want to make them removal I would think C Channel lined with UHMW strips would provide easy to slide, prevent rattle and make it easier for one person to insert the panels. Make sure you don't use structural type of channel as it has tapered legs.

Either of these two types of channel would be good choices.
http://www.onlinemetals.com/merchant.cfm?id=1008&step=2&top_cat=60

http://www.onlinemetals.com/merchant.cfm?id=297&step=2&top_cat=60

HDPE Boat Board would make excellent liner but I haven't found anything less than 1/2 inch thick. 1/8 to 1/4 inch thick HDPE would be perfect depending on how you plan on attaching it to the aluminum channel. I would use counter sunk screw with tapped holes in the aluminum.
https://www.onlinemetals.com/merchant.cfm?id=181&step=2&top_cat=181