Large solar array support beams

[s/v Jedi]

Originally Posted by Grith

Lots of fancy stuff being done here. Congratulations.
Personally I just added 540w of thin frame hard panels over my existing Bimini by adding an additional rear stainless tube and using thumbscrew clamp style mounts to securely attach the three panels rear edge and the same clamps over the canvas covered front Bimini tube to attached the front.
I then replaced the front tensioning straps for the Bimini with matching stainless tubes providing a more solid front support.
Combined with my pre-existing 180w identical tilting panel attached to my rear targa bar I now have 720w of unshaded and easily removable thin frame hard panels on my 28 foot trailerable yacht.
This is in addition to my tiltable cabin roof top panel attached with the same clamps allowing port starboard tilt adjustment at anchor and my dodger top flexible panel which moves up to on top of my bagged main.
Total is just under 1kw on a 28 foot trailerable yacht set up for extended coastal and inland waters expeditions.
To date the whole setup has survived a several hour crossing with winds over 35knots with an exceptionally short steep swell on Lake Alexandrina here in South Australia.
The Bimini mounted solar array power two lithium EcoFlow Delta portable power banks allowing me the equivalent of being connected to shore power whilst out remote cruising. These are in addition the yachts usual AGM house starter bank running all the regular systems charged by the other two panels.
We cook via induction, our hot water is an 800w 240v element electric storage system (outboard so no heat exchanger) , fridge and separate freezer are electric compressor type (again no inboard for eutectic) and we also charge our torqeedo light winds auxiliary batteries which also doubles as our dingy outboard and a variety of other occasional 240v appliances.
The EcoFlow units have been connected to our shore power system in our fuse box with an electrician fitted change over switch.
The main other unusual expense was the Ferris plastic thumbscrew clamp style panel mounts. They do however mean that all the panels can be easily removed and stowed below if really bad weather threatens.
The old iPhone shown below (degraded battery so permanently on charger cord) is providing a dedicated remote charging/discharging and state of charge monitoring and output remote switching for the EcoFlow units which are located in plastic boxes attached to access hatches under the dinette seats on both sides of the yacht. The green lit switch is the hot water service on and heating. Input and output and state of charge can be read on the photo.

Yes, solar power is a game changer and, in my view, soon a requirement for modern life.

We started in 2003 with 6 Siemens panels of 110W each. Two were mounted on this same arch, so that’s 220W and the previous array mounted there was 1,125W and this new one a whopping 1,760W.

Where the other 4x 110W panels were, we now have 2x 375W so that went from 440W to 750W. In the future I am planning to replace those with two panel cassettes like we’re now building for the arch, going from 750W to 1,760W and a grand total of 3,520W… still less than what nfbr has on his arch on a catamaran but good enough for us to do away with the last non electric item which is our propane grill in the cockpit.

We run a large 150 liters/hour watermaker and even our A/C from solar and lithium batteries, as well as a full electric galley where we bake bread twice a week, make our own granola, yogurt etc. so a lot of energy used.
I hope one day to add some electric propulsion

[s/v Jedi]

I just found the picture that had me start on the solar panel cassette design
I don’t think I posted this yet…

[Grith]

I cannot reach that high on our truck camper tow tug but it looks a neat solution. We have another 600w up on top of the camper and one of theEcoflow Delta max 2000 units moves from the yacht to the camper when we are using that. It’s the primary advantage of using an all in one portable lithium power pack that includes computer controlled fast charging, mppt solar controller, 2400w sine wave inverter with over boast and startup capabilities and remote monitoring, parameter changing and output switching via phone app.
Again to date I have left the campers 280ah AGM battery system in place and just added the EcoFlow to the grid connect circuit with professionally installed change over switch.
The truck is 24v and when running easily also charges the EcoFlow at 380w and the yacht has a 12v to 24v vitron converter also allowing charging at about the same when the outboard is running though this barely copes.
The EcoFlow units also do duty as both solar charged house rain water and gardening river water pumps power source and as an uninterrupted power supply back up at home when we are not camping or cruising.
Our remote riverfront home/travelling base also has 9.2kw of roof solar but no dedicated battery yet as these are still uneconomic.
Soon I hope with further price falls.
When home batteries are fitted we will be able to go off grid there as well as on our yacht and camper.

[Lee Jerry]

Originally Posted by s/v Jedi

Jedi is on the hard in Port Canaveral. Luckily we have a little hideout place in Titusville and one of the first things I did there was convert two garages to air conditioned workshops

One is normally a car garage and here I have a large workbench, table saw, bandsaw, drill press etc. so it’s where I make a lot of dust and the other is normally a storage/ utility room with a golf cart garage where I made a 4 x 8 assembly/ paint station with dry racks etc. so this is the clean room. Both had A/C installed right after we bought it

I always used West System as this was easy to get in the Caribbean but now in Florida I have been buying more TotalBoat epoxy because it comes in plastic containers that stay nice. I recently even tried TotalBoat 3:1 epoxy resin with West System fast hardener because I was in a hurry and took the risk and like people told me it worked great.
For most work now I use TotalBoat 3:1 epoxy with their slow hardener and have a couple gallons at hand most of the time (buy when they have a special ). This gives me a full cure overnight in the A/C so that’s good for this project as well.



That is great news! I had good hopes that the extra layer of unidirectional would achieve this



I plan to buy G10 3” wide by 1.5” thick bar stock and cut/mill supporting pieces like mounting pads and the strut attachment from it. For the strut attachment I also hope to extend the support from the strut further up the beam.

I do not know the angle that the strut comes up with yet but imagine it to be similar to our hydraulic boom vangs. From the G10 bar stock I want to cut triangles that have the longest side up against the beam, the shortest side facing the strut and here a 90 degree corner towards the third side that spreads the load further along the beam. The shape of a boom vang attachment.

At the back end, at the sharp corner, i will cut a piece off to get a flat surface perpendicular to the beam, so that I can glue a stop block to the arch to keep the triangle in place. Between the beam and the G10 block I plan to put “carpet tape” as a cushion to deal with any irregularities between the two surfaces and keep it a little in place, with one or two Dyneema lashings around the beam as the main fastener. Maybe I will glue a couple small side rails to the underside of the beam for the block to sit in between.

Between the triangle and the stop block I can put shims for tuning. Also, where the strut mounts to the arch tube, I plan to have a stainless steel M10 threaded rod for length adjustment.

As I am sketching this, I found that none of the lashings interfere with anything so I can skip the holes through the center of the beams and simply lash all around them. This will double the length of the lashings but I don’t expect any trouble there and can simply re-tension when needed.
I will need to drill at least one hole through the triangle block for the lashing.

I am amazed about the strength of the tubing from DragonPlate. Here is the end connector that I want to thread for M10: https://dragonplate.com/1-end-connector-blank
The other end, at the G10 block: https://dragonplate.com/1-male-clevis-connector
will engage with clevis jaws that I will machine in the G10 so I can put a 1/4” clevis pin through.
Here is the tubing: https://dragonplate.com/axially-opti...tube-1-id-x-96

FYI, I'm leaving for two weeks and not taking the laptop, so no more analyses for a while. I should have intermittent internet access, I'll be checking in on CF from time to time, but not sure when or how regularly.

[Lee Jerry]

So no update? Has construction started?

[s/v Jedi]

Originally Posted by Lee Jerry

So no update? Has construction started?

No, we’re still stuck in the old world for a while, then make our way back over the ocean. I’ve built them in my head a couple times already

Pretty sure I am going to vacuum bag these. What is sure is that the beams will cost more in materials than everything that will be mounted on them haha

[RaymondR]

Hi Jedi,

Decades ago I needed a very light FG slider to fit into and slide inside square hollow tubing. I made a mould from timber in sections which clamped together. The lay up was done with chopped strand mat and it came out looking beautiful with very smooth surfaces both inside and outside. Might be something to ponder on.

[s/v Jedi]

After a glorious Atlantic crossing aboard the Queen Mary II, we arrived back in Florida yesterday and this project is on

Unless someone talks me out of this, I have made two changes:

1. I am switching from Coosa board to plywood. I have found decent quality marine and birch plywood at our Lowe’s or I need to drive 4 hours each way to get Okoume BS1088 plywood.

I plan to laminate the core from three layers of 3/4” plywood with a 6 ounce layer of E-glass in between the layers.

My reasoning: the weight difference is less than 30% savings with Coosa, while it’s stiffness and strength is less. Since I have eliminated all drilling into the beam, I will not have any trouble with moisture, which was the last advantage that Coosa had, but it is highly countered by the price difference as the Coosa board will probably be drop-shipped at very high cost.

2. The loading on the inside beams is only half that of the outside beams. The reason is that the weight of two panels is shared by two beams when the lower panel is retracted, but when you slide that lower panel out, the two panels balance on just the outside beam while the inner beam has no load.

For this reason I looked if I could eliminate one beam and use just a single beam in the center. This means the center beam gets full load with the panels retracted, with the outer beams at half load and when the panels are deployed, the outer beams get full load and the center beam nothing.

This is possible when I can shim beams to get the tops of all three aligned and when I can use one continuous angle profile across the beams to mount the panels in. As the “double cassette” is only two panels wide and the widest panels I see are less than 45”, this angle can be made from 8’ long material that is readily available.
For aligning, I had already decided to use G10 fiberglass pads between the beam and the arch tubing so I can tune those pads thicknesses to align the beams.

I plan to make these angle profiles from a composite of 1/2” thick plywood core, glued into a 90 degree angle with a box joint and epoxy and fiberglass skin. This being fiberglass creates electrical isolation between the metals used with the panels and the carbon fiber used for the beams.
I have a project that has been on my list for 6 years which is the box joint jig from William Ng for his table-saw sled thatI made years ago.

I ordered 44” long sliders so these angle profiles will be 88” long or a little more depending on actual slider length.

While setting up the shop here, I am sourcing materials and filling in details like how to mount all that while in our marina slip etc. I plan to first mount the beams with the permanent Dyneema lashings, then use temporary velcro bands or zip ties to position the angle profiles across the beams, then use the mizzen halyard to hoist first the lower panels in place, followed by the upper panels. When those are secured, the permanent lashings can be made to replace the velcro.

Coming back to the first steps: I want to make the cores for the three beams then take those to the boat for measuring shims for alignment as well as details for the struts. As it will probably rain, I will seal these cores with the penetrating epoxy that I used with much success in earlier projects.
Then I must design the rotary jig to mount the cores in so that they can be rotated while laminating the carbon fiber. I think I will use a plastic shrink wrap foil instead of vacuum bagging which would work very well. The plan is to use a foam roller and brush to apply epoxy, then an aluminum thin roller to get the air and excess epoxy out. After the final layer, first peel ply then the bleeder cloth for the excess epoxy, then the plastic shrink wrap for clamping.

Of course the solar panels that I want are sold out everywhere. Renogy is doing pre-sales on 450W bifacial panels that would work… or larger Q-Cells panels. Many of these panels have low frames, 30mm or less high, while I’m trying to get 35mm or even 40mm frames.

[nfbr]

The strength of a beam is in the top and the bottom (compression and tension)
Why use foam core as per conventional fibreglass or carbon construction. The weight saving will be significant.
My 3.6kw array frame weighs 55kg including 6ft legs.

[s/v Jedi]

Originally Posted by nfbr

The strength of a beam is in the top and the bottom (compression and tension)
Why use foam core as per conventional fibreglass or carbon construction. The weight saving will be significant.
My 3.6kw array frame weighs 55kg including 6ft legs.

When you read back in the thread, you can see how we came to the materials for core and carbon laminate schedule. Regular foam isn’t strong enough (not enough shear strength) while Coosa board, which is a foam core material with fiberglass reinforcement, is strong enough for the 26lb variant. Birch plywood is stronger and the Coosa board only weighs 30% less, but Okoume BS1088 plywood has the same strength with much less weight, challenging the Coosa board for my application.

Traditionally Coosa board is used in carbon fiber beams, as well as hard wood species either solid or marine plywood.

[s/v Jedi]

I took a gamble and pre-ordered the new Renogy 450W bifacial panels.

They are said to be the same as their 450W monofacial panels and the article number only has an additional “T” in it so we’ll see.

All the other bifacial panels are hard to get at the moment and we simply must have the power

So 1,800W installed with a maximum 30% bifacial boost for 2,340W.

They are just over 44” wide so stick out of the slider a bit. I may make the bottom of the cassette angle profiles a bit longer to hide that from view.

The advantage is that they are not as long. Instead of an expected 210cm these will probably be 190cm which is much shorter. This raises the big question of may be making the beams shorter….

But what when in the future get other panels that are longer. We would need cassettes with a wide bottom to reach back to where the beams end. I will probably keep the beams at 210cm.

[s/v Jedi]

Today I received the 44” long full extension sliders and I ordered the carbon fiber.

The sliders are exactly what I wanted and for the carbon I took advantage of a sale for regular weave carbon that has been going on with multiple suppliers but others were already sold out. I could not get the 12 ounce unidirectional so I went for 9 ounce and do three layers instead of two.

As if the project list isn’t big enough, I also started working on a cockpit table, which we never had and I ordered a LagunUSA table leg/mount system.

I already have the Jatoba lumber but still need to choose the hinges for the folding wings, as well as work out dimensions.

Attached a picture of the sliders as well as the carbon fiber order.

[team karst]

Sorry; can't believe plywood is in the discussion. I bought a sportfish one time that had freshly made plywood cored fiberglass flooring for the marlin tower. Within a year of exposure, I knew that someday I had to rebuild them. Yep, barely 2 years from layout, they exploded with rot. I replaced with 1" what I though was WesCore (?) and one layer biax top and bottom. This flooring was supported by Al angle shapes in a 3 x 6' rectangle, and two of those side by side. I also made a deck walkway about 5' long and 12" wide, supported ONLY on its long side/ends. Same technique, only I used Divinycell H60 (the green one) for coring. It supported even a 300# crew member. The panel weighed 5 to 10 lbs. edit: I did have a 4" vertical thin blade on bottom side to reduce deflection..
Not certain if I used 2x or 1x on the biax. Seemed like new a decade later, always exposed to SF weather. NO plywood in the rain. Hard to imagine how to keep out water....

[Senojev]

Originally Posted by s/v Jedi

I would love to have been the one to come up with this but I think it has been the overland community who put these cassettes on the roof of their vehicles.

It is very easy to get the sliders. Here are the 44” sliders on my parts list: https://www.amazon.com/VADANIA-Drawe.../dp/B08147TPN2

I have used similar ones for our fridge and freezer boxes before and they come up to 500lbs capacity or even more.

Did you notice that the sliders you linked to were just galvanized steel? In a saltwater environment, they will not hold up beyond a few months. If you search, you can find full 316 SS full extension sliders. Not cheap but will last.

[s/v Jedi]

After actually ordering materials, this is the revised plan;

The beams will be 210cm long which is just under 7’. It will have a composite plywood (need one sheet $113.-) with fiberglass core and carbon fiber skin.

Core: I have selected a 3/4” thick marine grade Douglas Fir plywood and 1708 fiberglass. There are three layers of plywood with two layers of 1708 in between. I plan to use some locating dowels so that things don’t shift during clamping it all down with epoxy resin.
I will first wet out the fiberglass (on plastic) and plywood surfaces, then add a little microfiber filler to add some glue to the plywood surfaces so any imperfections are filled. Then put it all together, insert locating dowels and clamp down.

The four long side corners get a 1/2” radius roundover to help the carbon fiber conform to the shape. I will keep the core long so I can cut it to exact size, getting rid of the carbon edges etc.

This core will have at least 3 times the shear strength of a Coosa Board core. The Douglas Fir alone is 2.5 times as strong as the Coosa Board.

After all the cutting, milling and sanding, I plan to seal the core with the penetrating epoxy, then sand any pooling epoxy off after cure.

With these three cores I will do a first fitting aboard so see where the struts end up, which angle these make with the beam etc. This allows me to make the fiberglass blocks that help mount the beams.

Carbon fiber skin: the supplier I used didn’t have the 12 ounce unidirectional I wanted, but did have nice 9 ounce, 12” wide unidirectional. This means I need ine additional layer, resulting in the following schedule:

1. 203gsm plain weave (one cloth piece per layer)
2. 203gsm plain weave (one piece per layer)
3. 193gsm biaxial 45/45 (single piece for two layers)
4. 305gsm unidirectional top and bottom only
5. 193gsm biaxial 45/45 (same piece as layer 3)
6. 305gsm unidirectional top and bottom only
7. 203gsm plain weave (single piece for two layers)
8. 305gsm unidirectional top and bottom only
9. 203gsm plain weave (same piece as layer 7)

Total 1,198gsm sides and 2,113gsm top and bottom.

I will make a jig to turn the core like a rotisserie, which I can use both for carbon fiber layup as well as the paint job.