Feedback on initial solar arch design?

[sona1111]

Hello All,

I've been toying with the idea of building a solar arch from consumer parts from mcmaster-carr. (bolt together, no welding), for example, the 1" bars from: https://www.mcmaster.com/structural-...-and-fittings/

I'm looking for any tips to improve the structure, or warnings about the choice of material or approach. (It's the first time I'm trying anything like this)

-The blue bars are the new constructions
-The silver bars already exist on the boat
-The green panels are size 44" x 20", which seems to be a standard rigid size
-The side mount with the red cylinder is a potential placement for a vertical axis wind turbine (lift type), but I'm still doing research on this, and might remove this section of structure. (It would be the same on both sides if I kept it)
-The Grid / two levels at the top would be used for storing fenders or other lightweight objects.
-The attachment points to the deck / transom would use either the "offset" or "round-adjustable-angle" versions of these parts: https://www.mcmaster.com/structural-...nent~rail-end/





(openscad code to make this: https://pastebin.com/JYUQTFL9)

Thanks for looking!

[coopec43]

Are you not at all concerned about adding weight high up on your yacht?

Stability Calculations For Solar Arch
https://www.cruisersforum.com/forums...ch-109615.html

[tkeithlu]

+1 on coopec43's concern for weight.

It's a rather complicated cage made of rather light (1" diameter) aluminum. Most such arches more closely resemble the one cooppec43 posted. It is well-braced, although I'm surprised that you didn't gain strength from the existing railings.

The structural joints depend on set screws in aluminum. That's not much of a joint when the wind gets under it.

[sona1111]

Hello coopec43 and tkeithlu.

Summarizing the suggestions so far, it seems like:

-there are recommendations against the second set of horizontal bars, creating the boxes?
-I should also bridge some of the small horizontal sections from the existing railing using either additional hardware or clamps.
-I should use a tube diameter greater than 1"

As I mentioned, I am fairly new at this, so I'm unsure how to calculate the safe weight of a structure. I would, of course, prefer to reinforce more than necessary in all cases. Mcmaster offers other tube sizes of 1-1/4, 1-5/8, and 1-7/8 . Any thoughts here? Is bigger always better? Do you know which tube size is used in the example posted above?

I'm also not at all experienced with pipe-bending to make shapes similar to those shown above. I was planning only on doing bends for the two sets of tube that would attach to the transom.

Thanks again for the feedback, I'm glad have a few warnings to look into!

[Bellinghamster]

A couple comments:
You don't need the "box" frame on top - it doesn't add any strength in the directions you need it. incorporate some gussets (diagonals) in the corners to stiffen it side to side.

You're going to wipe that vertical axis generator off there the first time you scrub a piling, tall dock, seawall or vessel - I woudn't have anything hang outside the toerail on the sides

Square is UGLY (sorry, but it is). For the amount you're going to spend on all the fittings and materials, you can probably find a fabricator to do some nice bends and make a more traditional arch for not much more. I made mine out of (2) 1.5" aluminum pipes (1 fore and 1 aft arch tubes from the deck, up and over). Put a bit of an arc in the top horizontal section using a tubing roller and made the corner bends using a pipe bender, then had a couple front to back tubes welded at the top corners and some aluminum angle welded on the top to mount the panels to, and some 2" x 3" x 3/8" plate for feet. Most machine shops can do this type of work - it doesn't need to be "marine". If you measure and make some angle blocks to mock-up the deck angles at the mounting points for use at the fab shop it'll save $ and hassle. Cost for mine, including new aft stanchions, gate, rails, arch, solar mounts, wind generator and radar mount poles and sockets for the hard top lifeline, all welded together was $1400 (granted that was 15 years ago...)

[wingssail]

Aside from being totally unattractive the structure you have designed is a mistake for other reasons:

• You are adding weight and windage aft and high up, this hurts performance
• You plan on storing other items also high up and aft, which is more windage and more weight, and more performance loss
• The joints and corners with fittings and set screws will not be strong
• You have a small but attractive boat, you will ruin the value of this vessel

Accept your boat for what it is, keep it simple, keep it's performance for what it is, and enjoy it until you are ready to upgrade.

[coopec43]

I agree with Bellinghampster's comment.

In particular the use of aluminum and getting the tubing professionally bent. If you get someone who specializes in making up dodgers, biminis etc for boats it won't cost you an arm and a leg and they will probably help you with the design.

If you are thinking of taking your yacht out of sheltered waters I think what you are proposing is a bad move. Have a look at this:

Heavy Weather Dynamics: Upwind Sailing, Windage and Resistance

[sailingabe41ds]

I'll be brief...yuk.

Abe

[Sailmonkey]

Feedback?

It’s hideous and likely not strong.

The VAWT, while generating little power won’t last the first docking.

The windage is through the roof! A bayfield 29 is already challenged on the wind, this makes it worse.

And finally, I’ll bet you can’t buy all of those fittings for less than you can buy the small Pre made arch from here

https://www.atlantictowers.com/products_sail_arch.php

[sona1111]

Hi All,

I won't try to hide that I'm a bit taken aback by the volume of comments specifically focused (I believe) on using square shaped joints in place of rounded off joints. (Mainly because the arguments seem to be focused on cosmetics, rather than structural durability (??))

Anyway, I am still interested in attempting some cost saving by DIYing this project. I have some time to spend on it, and I currently can't mentally justify dropping 2.5K on two pieces of bent tubing and a few fittings from atlantictowers.

Perhaps my attempt/general design is simply not serviceable. I had a little trouble searching for DIY mount projects on this forum (by topic titles). Does anyone remember seeing someone else try to complete a similar project? Perhaps I can derive some ideas from their design?

I also see Bellinghamster mentioned getting two 1.5" tubes bent at a fabricator -- does anyone have a recommendation for the wall thickness of these tubes? If I just started with the two bent tubes, would it be acceptable to use the set-screw attachments for crossbars / deck fittings afterwards? I really don't trust getting welding done ahead of time and doing that kind of work afloat is highly impractical.

For reference, here is the same general design with slight modifications from comments (disregarding cosmetics for now):





I enjoy the satisfaction of DIY projects, and being confidant to do the process again if needed, which is another reason I tend to stay away from relying on others to do all of the work for me. I hope this is at least partially understandable.

[coopec43]

"I currently can't mentally justify dropping 2.5K on two pieces of bent tubing and a few fittings from atlantictowers."

What is that meant to mean?

Why don't you google (Image) something like "DIY Solar Arch yacht" to get ideas?

[Sailmonkey]

Originally Posted by sona1111

Hi All,



I won't try to hide that I'm a bit taken aback by the volume of comments specifically focused (I believe) on using square shaped joints in place of rounded off joints. (Mainly because the arguments seem to be focused on cosmetics, rather than structural durability (??))



Anyway, I am still interested in attempting some cost saving by DIYing this project. I have some time to spend on it, and I currently can't mentally justify dropping 2.5K on two pieces of bent tubing and a few fittings from atlantictowers.



Perhaps my attempt/general design is simply not serviceable. I had a little trouble searching for DIY mount projects on this forum (by topic titles). Does anyone remember seeing someone else try to complete a similar project? Perhaps I can derive some ideas from their design?



I also see Bellinghamster mentioned getting two 1.5" tubes bent at a fabricator -- does anyone have a recommendation for the wall thickness of these tubes? If I just started with the two bent tubes, would it be acceptable to use the set-screw attachments for crossbars / deck fittings afterwards? I really don't trust getting welding done ahead of time and doing that kind of work afloat is highly impractical.



For reference, here is the same general design with slight modifications from comments (disregarding cosmetics for now):











I enjoy the satisfaction of DIY projects, and being confidant to do the process again if needed, which is another reason I tend to stay away from relying on others to do all of the work for me. I hope this is at least partially understandable.

This design is significantly better than the first.

Now price your BOM and see if it still makes sense.

[sona1111]

Sailmonkey:

Thanks. This is literally just the first design, without the windgen (which I was very skeptical about anyway, from my first post), and without the second row. Otherwise it is exactly the same.

For all fittings and pipe for the original design from mcmaster I was looking at about 1.5k. I've not tallied up this one yet, but I would imagine it would now look more like 1.1 or 1.2k, does that sound reasonable? (I'm pretty frugal so I would likely start to look elsewhere for better/bulk prices, but this was just an easy website to navigate so I started with it as a backup)

Thank you for taking the time to reply.

[Bycrick]

I added a solar panel arch in 2004 to my Norseman 45’. It’s made of 1” SS tubing welded to the pre-existing aft rails of the same material. The now 800+ watts of solar panels are held on to ONE of the bows so that they can be tilted fore-aft, with 2 clamps on each panel set. They’ve survived 12000+ sailing miles and one hurricane. IMO, the frame/supports don’t need to be any stronger than the panels themselves.

[Cheechako]

I think you could go a bit higher and wider. You could rent a room up there that way when in port.