Advice help on a chandelier

[Gergely]

Last time when I talked with the clients they asked me if I could make a frame for a very big chandelier like this:

They want it to be around 3m / 9' dia. But unlike the one in the picture, it can be only 45 cm / 1,5' tall. They have somebody to install all the non-steel elements and do the wiring - I'm not capable nor willing to do that.

I said I have to think and plan ahead a bit before I can say anything. I searched for any structural schemes for this kind of chandelier but couldn't find anything. I was thinking that two, maybe three cold bent pipe rings would be enough for the main support, and welded tendrils could act as additional support elements. Something like this:

This image shows two things very badly: the rings are heavily connected together by welded bridges. And the whole thing has to be made of two separate parts that are connected by bolts. 

The chandelier will be attached to the ceiling at 4 points. At the very first calculations it will weigh around 200kg / 440lbs so at least 4 point securing is a must, I think. 

If anyone has any suggestion on this, please comment. I shoot pretty much blindfolded on this. Have been thinking about it, but that's all. The clients said there are no one around here who would accept this challange (or does this kind of work at all). 

Thank you for your valuable help!

Bests:

Gergely

 

[Glenn]

I started a new thread on your chandelier as it is a new request for assistance.

Make a ring say 9 feet diameter and 6 inches verticle deep and fill the ring with scrolls, flowers, etc. 

440 pounds is a lot of metal. Instead of pipe, could you design with thin walled pipe such as conduit, flat bar bent the hard way, or even angle iron bent the hard way? 

[Gergely]

Thank you, Glenn! - It's much clearer as a new thread.

The clients have very exact image about the looks of the thing. They want to follow the pictured one which is the chandelier of the Beverly Hills Hotel. They order all the glass and plastic elements, the flexible conduits for the electrical cables etc. These parts (ie. there will be at least 250 glass roses) will weigh the most of the 200kg.

So I have to find out a sturdy but lightweight construction for holding together this whole mess. Also it needs to be two half round piece bolted together, otherwise it cannot be carried inside the hall it will then hang in.

I thought of using pipe because it is the stock that locally can be bent into ring shape most easily. You are totally right about using as thin walled version as it is possible. It is also important that the pipe has to be thick enough to bear the welds as well.

My calculations go with 1" ID 1/8" thick pipe (32mm OD, 3mm wall thickness), It weighs 4,4 lbs/2kg per meter. The biggest ring is 7m long stock, so it weighs 14kg / 31 lbs. The middle ring is 4,4 m long, so it weighs 9 kg / 21 lbs. The inner ring 1,9m and weighs 4kg/ 9lbs. This sums up to 27 kg / 62 lbs for the rings. I thought some T-steel would suffice to fix them together. With 1,8 kg / 4lbs per meter the four pieces of T-steel weighs 5,8 kg / 13 lbs. 

This makes the whole main frame weigh ~35kg / 77lbs. (The additional tendrils are being made of 5mm dia round, a 6m long rod weighs around 1kg.)

The only question is: is this sturdy enough?

Another drawing to show better picture what I was talking about.

Again, any suggestions are welcome! Thank you very much!

Gergely

[RobbieG]

You are going to need a large safety factor built into this since it is attached to the ceiling - what is the construction of the roof and can it safely handle this sort of load?

Rather than rings connecting at angles might it be better to have a central structure on the main ring that the smaller rings are attached to vertically? It will add a little weight but would change joint loading from torsion to tension, and would still be hidden by the decorations - it also appears to be the typical design employed on tiered chandeliers. I would definitely recommend talking to someone with structural design experience if that is not your background, just for the reassurance that the design is safe.

[Gergely]

Thank you, RobbieG! Good suggestions - I'm making a new drawing based on what I understood from your words. 

The roof question was the first I asked the clients about. They said there is thick timber roofing. I definitely need to see it myself.

Bests:

Gergely

[SLAG]

Have dry rot in mind when examining the wooden beams. Some of these fungi need only surprisingly little moisture to get growing. I am alluding to both red and white rot.

The destruction is not always apparent.

But it can be considerable, even structurally threatening.

A visual inspection is not enough. Many home inspectors use a long awl to probe the wood.

Also, it just came to mind now, there may be termite damage. Perhaps you do not suffer from those little darlings in Eastern Europe,. But they can trash wood thoroughly. In worse case scenarios, all that is left of the wooden beam is a thin skin, a hollow shell that looks solid.

Hope that helps.

SLAG.

[rockstar.esq]

You might want to lace aircraft cable through the fixtures and up into the structure as a backup/ seismic support measure.  Weird stuff happens.  My first boss at an electrical contractor told me about a fancy restaurant that had a huge crystal chandelier in the main dining area.  The bus boy was cleaning it by standing on a ladder and spinning the fixture towards his position to reach all of the crystals.  Every time he cleaned it, he rotated it in the same direction.  That fixture was held up with a threaded pipe connection.  Some time in his first month, he was in the main dining room cleaning and there was a huge crash.

Everyone ran into the room to see if he was OK but he'd disappeared.  The chandelier was ruined and the bus boy was never seen again.

 

[Gergely]

15 hours ago, SLAG said:

Have dry rot in mind when examining the wooden beams. Some of these fungi need only surprisingly little moisture to get growing. I am alluding to both red and white rot.

The destruction is not always apparent.

But it can be considerable, even structurally threatening.

A visual inspection is not enough. Many home inspectors use a long awl to probe the wood.

Also, it just came to mind now, there may be termite damage. Perhaps you do not suffer from those little darlings in Eastern Europe,. But they can trash wood thoroughly. In worse case scenarios, all that is left of the wooden beam is a thin skin, a hollow shell that looks solid.

Hope that helps.

SLAG.

Thanks Slag. I'll get the needed info. Luckily one of the clients is a "woodsmith" so he knows the structure and wellbeing of this house. 

No termites here, thank God! Or at least I've never heard about any termite damaged thing.

 

13 hours ago, rockstar.esq said:

You might want to lace aircraft cable through the fixtures and up into the structure as a backup/ seismic support measure.  Weird stuff happens.  My first boss at an electrical contractor told me about a fancy restaurant that had a huge crystal chandelier in the main dining area.  The bus boy was cleaning it by standing on a ladder and spinning the fixture towards his position to reach all of the crystals.  Every time he cleaned it, he rotated it in the same direction.  That fixture was held up with a threaded pipe connection.  Some time in his first month, he was in the main dining room cleaning and there was a huge crash.

Everyone ran into the room to see if he was OK but he'd disappeared.  The chandelier was ruined and the bus boy was never seen again.

 

Uhmm, nice story, we really don't want to happen anything like that, do we... I try to keep in mind when planning that above its own weight this structure has to be able to hold a grown drunk man. But you're right: idiot proof construct is the way to go.

The aircraft cable is an awesome idea: lightweight, sturdy, flexible.

Thank you for the suggestions!

Bests:

Gergely

[Gergely]

17 hours ago, RobbieG said:

Rather than rings connecting at angles might it be better to have a central structure on the main ring that the smaller rings are attached to vertically? It will add a little weight but would change joint loading from torsion to tension, and would still be hidden by the decorations - it also appears to be the typical design employed on tiered chandeliers. I would definitely recommend talking to someone with structural design experience if that is not your background, just for the reassurance that the design is safe.

Does this drawing show the concept you were talking about? Very sorry for the lousy technique, I still haven't learned how to use any CAD-like programs.

I tried to use colored lines to show the different vertical levels. The heigth is way out of the real proportions in this picture, but I had to make it visible.

Thank you:

Gergely

[Daswulf]

Shows more to me Gergely. I still wouldn't want to make all of those leaves and flowers . I can't wait to see what you come up with tho. 

[Gergely]

No, no, I'm not doing the detail work. Only build the structure. Although I'd like to make the leaves - not totally by hand though  . 

[RobbieG]

8 hours ago, Gergely said:

Does this drawing show the concept you were talking about?

Yes that's pretty much it, because the joining members are in tension you can also go for a lighter section than before - even hollow section. Don't worry about the sketch, the intent is clear - if everyone had to resort to CAD to get a concept across we would be in trouble!

[JHCC]

For the joints between sections, I worry about the strength of the bolted connections. What if you were to use thinner pieces that fit inside the tubing of the segments, like an old-fashioned tent pole or the pegs that connect sections of steel scaffolding?

Thus:

[Gergely]

3 hours ago, RobbieG said:

Yes that's pretty much it, because the joining members are in tension you can also go for a lighter section than before - even hollow section.

Brilliant thinking! Thank you!

48 minutes ago, JHCC said:

For the joints between sections, I worry about the strength of the bolted connections. What if you were to use thinner pieces that fit inside the tubing of the segments, like an old-fashioned tent pole or the pegs that connect sections of steel scaffolding?

That's a very valid point and a very good idea - I think it trough but I really like it. Thank you!

Trying to make a sketch for the clients as a starting point. They want to know if I am capable to do this, and I want to know a bit more details: how many leaves, what kind of leaves, the roof dimensions etc. There is a lot of things I should know before calculating any numbers...

Bests:

Gergely

[Gergely]

I just received an info from the clients: there's gonna be around 1000 pcs of leaves  and circa 300 pcs of the glass rose lamps.

Now I'm relieved I don't have to make the leaves...

G

[Judson Yaggy]

If you did you'd be REALLY good at leaves when you were done.  10 per hour for 10 hours and it would only take you 10 days.  

[Gergely]

3 hours ago, Judson Yaggy said:

If you did you'd be REALLY good at leaves when you were done.  10 per hour for 10 hours and it would only take you 10 days.  

That is true. Although I have my doubts.

I have planned the how to, laser cut and then pressed under fly press, finishing touches with hand hammer. But I can't compete the 0,32$/leaf price an Italian firm can offer. Those leaves doesn't even look bad. - So if I get this work I will get better at welding thin leaves to tendrils.  That's not that bad either

Now I'm waiting for the price offer from the pipe bender. Was thinking about the structure and now I think of using carabiner swivels and steel chain for the vertical hold. It looks like an easy and efficient way for the very short vertical distances.

Bests:

Gergely

[Marc1]

Would like to see a picture of the roof cavity. Ceilings are not made to carry extra 200k without any modifications. 

At the very least and providing the roof structure allows it you would need to suspend the center of the ceiling from the roof trusses with a cable or chain ... worst case scenario you need an additional beam across the room and over the ceiling rafters supported by the walls.   That sort of load may seem to be ok at first but with time it can bend the rafters down. A builder can give you an idea. Access for the beam if one is required can be as simple as lifting some tiles and slide the beam in the cavity from the outside.

As far as the chandelier itself, anything you design must take the existing or modified structure into account. No point making a chandelier with support points that have nowhere to anchor to. 

And yes, I too buy some pre made stuff from Venice when the going get's tough and I need hundreds of little thingies. Their prices are as low as can be even when they are mostly made with a hebo machine or similar.  

arteferro dot com also sells glass flowers and ornaments but they are not cheap. 

 

[Judson Yaggy]

"Structural engineering and installation not included."   Are you an engineer or a carpenter and insured as such?

[Gergely]

4 hours ago, Judson Yaggy said:

"Structural engineering and installation not included."   Are you an engineer or a carpenter and insured as such?

Not sure I understand what you mean. Who said that you quoted? Or is it something I should declare toward the clients? - I won't do the installation, that's for sure. And no I'm not an engineer or carpenter. The clients know that I'm neither of those. 

Please don't get me wrong, I'm grateful for any point of views that is brought into my sight. I just want to understand better what you meant.

Bests:

Gergely

 

[RobbieG]

7 hours ago, Gergely said:

Not sure I understand what you mean. Who said that you quoted? Or is it something I should declare toward the clients? - I won't do the installation, that's for sure. And no I'm not an engineer or carpenter. The clients know that I'm neither of those. 

Please don't get me wrong, I'm grateful for any point of views that is brought into my sight. I just want to understand better what you meant.

Bests:

Gergely

 

I'm guessing he's suggesting you stipulate that the Structural calculations and installation are carried out by others who are suitably qualified. You are providing the chandelier ex works only and take no responsibility for any site issues. 

[Judson Yaggy]

Yes, sorry I should have been more clear.  RG expressed my intent better than I did myself.  I would put words to that affect into the bid document/purchase agreement/informal email that includes price.  

[bigb]

A chandelier of that size and weight warrants a lift. Once the lift is properly secured to the structure the fixture can be installed, cleaned and serviced easily. Among the more well known makers are Aladdin and Peter Albrecht.

[Gergely]

17 hours ago, RobbieG said:

I'm guessing he's suggesting you stipulate that the Structural calculations and installation are carried out by others who are suitably qualified. You are providing the chandelier ex works only and take no responsibility for any site issues. 

 

3 hours ago, Judson Yaggy said:

Yes, sorry I should have been more clear.  RG expressed my intent better than I did myself.  I would put words to that affect into the bid document/purchase agreement/informal email that includes price.  

Thank you, guys. It's all clear now. It will be a good thing to remember.

 

2 hours ago, bigb said:

A chandelier of that size and weight warrants a lift. Once the lift is properly secured to the structure the fixture can be installed, cleaned and serviced easily. Among the more well known makers are Aladdin and Peter Albrecht.

Thank you, I checked the makers you mentioned. I let the clients know about this option.

 

Bests:

Gergely

[Emily]

There is really good information. It has been a long time since the subject opened, but I wanted to thank you.