Flying DR arrays

[N.Webber]

Hi,

I have been asked by some readers regarding the flying hardware arrangement of my DR290s.
Ruther then answering each privately I am offering here the detailed design.
I've organized the drawings so that they are 'readable' to others beside my self…
I hope the drawings are clear to those who can understand them...

A few words though:
This flying system is actually part of my L.A.M.Post system
(learn more and see some pictures here: http://srforums.prosoundweb.com/index.p ... 198/0/0/0/

The main hang point/pin also functions as a safety anchor pin once engaged with the arrest hooks of the top beam.
This is also part of the mechanism for securing the array from rotating and swaying sideways.
Whatever system one uses to lift or hang the arrays by, these aspects must be addressed.

The placement of the main lift point (of the lift frame) was determined according to the COG point of my 290s.
Mine are loaded with the recommended drivers and horns, have front grills, and the hardware and reinforcement additions as shown.
Other/different builds and configurations may result in a different COG point and will require shifting this main lift point accordingly.

Here goes:







And this is how it all goes together:






Edited: Added pictures...

[marlon66]

hey do you have any plans of the LAMP post yet Still Interested!

[gdougherty]

IIRC, it's all available over at ProSoundWeb.com

[WB]

N.Webber, I like the quality of your work and ideas, top notch!

[Ron K]

You rock dude! Exceptional work my man, exceptional!

One question however! In your LAMPOST design do you use Grade-5 (8.8 metric) or higher fasteners?

Also on any weldments what type rod (60/70/80 series) or wire if Mig do you generally use?

[N.Webber]

Thank you all for the compliments…

Marlon, there is no organized set of plans for the LAMPost.
It's all in a crude file as different sketches, views and sections I made as I was designing and building the units.
I never got around to properly laying them out as usable and publishable reference drawings
(except for the ones shown above which I specially made for this thread).

Unfortunately, this will not happen in the near future as I am now busy advancing my BT-12 project:



(More info here: http://srforums.prosoundweb.com/index.p ... /0/0/6698/)

As Gdougherty noted, there is more info in the linked PSW thread. No actual plans or drawings like those I offered here
but there are some good pictures of the different parts and the build process.

Ron, all bolts are 8.8 grade. All the steel weldings are MIG, 1mm wire, 70 Ksi (IIRC…)

[LelandCrooks]

Wow Nimrod, that's come a ways from the original. Very slick with the handle adjuster.

[N.Webber]

Wow Nimrod, that's come a ways from the original. Very slick with the handle adjuster.

Yep, and there's no turning back...
This addition is setting the progress back a little but it's for the best as I am confident the result is a better product.

[N.Webber]

Hi there,

Wanted to update this thread with an improvement I recently did to the flying system.

In the original design, I didn't really think out the option of various J'ing of the array.
As the (old) lift frame had only one hang point, whenever I needed to J the cabs, I would hang them with the
proper splay between the cabs, and then simply pull back the whole hang with a wire tied to the bottom cab.

This wasn't acceptable in my book and I kept meaning to fix this issue. I finally found the time to re design
and build a new lift frame that includes previsions for some useful J configurations.
I also fabricated 'variable' adaptors that link the front feet (and corresponding recesses of the lower cab)
so that the front edges of the cabs are locked inline at any splay angle.

It so happened I got to try this upgrade at the same venue in which I used the DR290 and the L.A.M.Post for the first time, exactly 3 years ago.



Close up:



You got to love the sound that is coming from up high
There is something 'Godly' about it...

[Zack Brock]

Where did you get the hardware hanging points? Penn Elcom?

[LelandCrooks]

[N.Webber]

Where did you get the hardware hanging points? Penn Elcom?

There are many alternatives to Penn, like these:http://www.cargoequipmentcorp.com/catalog/?category=95
Google "L track"...

The hardware I used was from different sources.
The L track is from a German manufacturer that was available locally (don't recall the name right now)
I got a 'raw' 2m bar, and cut it to the pieces I needed.
The double stud fixtures I got the from a Penn Elcon distributor.
All the steel cable work was custom done at a local crane/lifting shop.

[DJPhatman]

Nim, I have a question about placement of the "L track" at the front sides of the cab. Why not more centered, even with the carry handle lift bar? Is it a balance issue? Thanks in advance, and as always, wonderful design and engineering.

Forum members, please take note that Nimrod Webber, the OP of this topic, is an engineer. Please, for safety's sake, be very very cautious when flying anything overhead. Even a 1/2 pound object becomes deadly when falling from above. 35+ pound speakers are outright scary!

[N.Webber]

Nim, I have a question about placement of the "L track" at the front sides of the cab. Why not more centered, even with the carry handle lift bar? Is it a balance issue?

Basically this could work. As long as this 'further back' position is still in front of the COG of the cab
(and a back hang is also used), I see no problems balance-wise.

Only issues I can see may be if/when there will be a need to J the array.

First, since these front points will not be at (or close) to the front edge, as a result of applying splay
between cabs, a space will be created between their front edges (and more so as wider splay is applied).
That may spoil the acoustic integrity and coupling of the cabs in the array.

Secondly, when (down) tilt is applied to a cab (or a complete array) and the rotation is about the front
top edge of the cab/array, the COG is shifted backwards.
If that front top edge of the cab/array isn't locked in the horizontal plane it will attempt to move (back) forward
to compensate for the COG backwards shift.
The end position will be somewhere in the middle as all forces (COG and those of the cables) reach a balance.

In order to achieve a smooth, continuous and true J shape of the array, we must provide a method of limiting this
relative horizontal movement between the cabs, or in other words, lock the front edges of each adjacent cabs together.

The closer the hang/attachment points are to the front edge of the cabs, these two aspects become less prominent
and are easier resolved.

Also, as every J configuration (cab count and splay) results in a different system COG location,
a range of corresponding lift point options needs to be incorporated into the main lift frame.
This range should provide a correct lift point that is in line with the complete system's COG at any of the designed array configurations.

[Turntablist]

Only issues I can see may be if/when there will be a need to J the array.

I've thought a lot about this and what I came up with is in this thread: http://billfitzmaurice.info/forum/viewt ... 14&t=10328

Basically what I've concluded is a solution very similar to your but instead of having wires at the front two hang points you have metal brackets with two mounting points in the upper cab and one point in the lower cab. To compensate for the shifting CoG one would have to have a solution with the mount for the top cab being movable back and forth (along a piece of truss or similar).

I'd be happy if you shared your thoughts. Words from an engineer in the knowhow weighs a lot.