Line Array Carts

C

Chris Greco

Sophomore
Feb 15, 2012
158
3
18
Yonkers, NY
I am about to embark upon a project to which I hope some of you already have done and have some do's and dont's as to how to be successful at it. I find that transporting line arrays in a truck its beneficial to stack them vertically to maximize the height of the box. I know some manufacturers have wheel kits for their bumpers and thats a solution but what if the bumper isn't truck pack dimensions. I am thinking about an oversize dolly of sorts that would rigidly attach as if it was just another box and possibly have some shock absorption to lessen the shock factor to the cabinet hardware on those not so smooth roads.

Fire away!!!
 
Re: Line Array Carts

Chris,

The fly hardware used determines whether it is OK to use it in compression, (stacked) rather than in tension when flown.

At minimum, tell us your cabinet type and truck width and height, and the maximum weight you are comfortable with.
 
Re: Line Array Carts

Art Welter said:
Chris,

The fly hardware used determines whether it is OK to use it in compression, (stacked) rather than in tension when flown.




At minimum, tell us your cabinet type and truck width and height, and the maximum weight you are comfortable with.
Click to expand...


I thought that with the line arrays I've encountered, you have the option of ground stack or fly so shouldn't the ratings on the hardware work in either direction? In which direction does the dynamic loading become more of an issue? Under the stresses of over the road trucking or when being flown with chain hoists? So with that in mind, one has to examine the actual hardware to determine if its obvious to where the weak link lies.


Mccauley M-Line
75Lbs per
33" Wide including pins
21" Deep

Truck door height 6'
Truck box width 80"
Shop door width 33"

I have a lift gate so weight isn't that much of a concern but, from some quick calculations I think I can go 6 boxes high which leaves me approx 6" of cart height. The one advantage of vertical stacking is if I have a height issue I can just remove a box to reduce.

My initial thoughts were to make the cart 30 deep x 34.5 wide. This keeps the pins and boxes safe from cases, truck walls, etc.

If I was to limit these to 6 boxes max then the total speaker load would be 450 lbs
 
Re: Line Array Carts

Chris Greco said:
I thought that with the line arrays I've encountered, you have the option of ground stack or fly so shouldn't the ratings on the hardware work in either direction? In which direction does the dynamic loading become more of an issue? Under the stresses of over the road trucking or when being flown with chain hoists? So with that in mind, one has to examine the actual hardware to determine if its obvious to where the weak link lies.


Mccauley M-Line
75Lbs per
33" Wide including pins
21" Deep

Truck door height 6'
Truck box width 80"
Shop door width 33"

I have a lift gate so weight isn't that much of a concern but, from some quick calculations I think I can go 6 boxes high which leaves me approx 6" of cart height. The one advantage of vertical stacking is if I have a height issue I can just remove a box to reduce.

My initial thoughts were to make the cart 30 deep x 34.5 wide. This keeps the pins and boxes safe from cases, truck walls, etc.

If I was to limit these to 6 boxes max then the total speaker load would be 450 lbs
Click to expand...

My understanding is that, no. The ratings for the rigging hardware when hanging vs ground stacking can and often are different.... and not just because of the "oh shit, it's gonna tip over!" factor.

Not knowing how they transport now..... I, personally, would not design and implement a transport method that put any stress on the rigging hardware unless it was manufacturer approved (good luck with that!). If the rigging hardware, for whatever reason, failed I would think that any insurance lawyer worth their salt would immediately point to the unapproved method in which the rigging hardware was handled. I think by designing your own vertical transport cages you may be opening yourself up to some amount of liability in the event of an equipment failure.

I may be being too cautious, but the safety of the people whose heads the equipment is flying over is more important than my convenience.....

If I am way off base, please correct me!
 
Re: Line Array Carts

So then maybe come up with a method where they say stack drivers down as if they were on thier individual dollys where the rigging hardware is not used. Like a self supporting series of trays holding a pair of boxes. Each cart would hold 4 boxes.
 
Re: Line Array Carts

I am ever the contrarian. Let me make a couple of points:

1 - Any thing getting flown overhead needs every attachment point inspected for tolerance every time.

2 - If trucking stresses may de-range ("oval") attachment holes or score some pins, they are quite underdesigned and should not be rigged overhead anyway.

3 - Educate yourself on basic material science and mechanical engineering i.e. mild steel v. 6061 aluminum, "double shear", etc.

4 - Buy replacement hardware from reputable sources.

I have seen many LA carts come out of various USA soundhouses with years of rigging experience. Most are smartly executed and operate as the time & labor savers they were designed to be. I worry more about the fatigued old points in many buildings more than the fresh, low-cycle hardware being attached.


Build and enjoy your carts!
 
Re: Line Array Carts

I totally get the, when dealing with hanging objects overhead concept and doing it safely concept and by no means want to minimize the importance of doing so correctly. So yes indeed regular inspection of rigging attachment points is key. with that being said it seems we are faced with a couple of options here.

The First being transporting the cabinets 5 high in a compressed mode (bottom cabinet being the attachment point to the cart with the others anchored to each other by means of the rigging hardware @ 0 degrees.

The Second would be the same configuration as above except maximizing the angle of the box's and putting the stress on the box itself and not the hardware. To further clarify this concept and to minimize the confusion, front point attached rear point detached so the boxes are physically resting on themselves and spreading the load across non rated surfaces (the box itself). Obviously the cart would need to be designed so that the curve of the array would not create an unsafe balance condition resulting in a top heavy unit.

The third would be stacking in pairs or more (pairs only work for me because of my shop door width) not utilizing the cabinet hardware but placing the cabinets in self supporting trays that would cradle them safely and securely for transport in groups of 4. I'm thinking line array milk crates.

The first concept to me is the only scenario that would put stresses on the critical hardware. I'm leaning towards the second scenario as my go to at this point.
 
Re: Line Array Carts

Our J's just ride on simple aluminum carts. Very straight forward and light weight. They're 45" wide so you can go 2 wide in the truck. Throw a moving blanket on top and ride the bumpers, or lighting truss on top usually.
 

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Re: Line Array Carts

I had carts made by a local shop... Used existing fly ware points for attachment . (Caveat) I drive the truck (always) so I know how hard of ride anything gets, the rig is never sub rented, and I close inspect everything at the start of the year, and during the flying process (again always by me) Covers are made by undercover NY.
 

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Re: Line Array Carts

Evan Kirkendall said:
Our J's just ride on simple aluminum carts. Very straight forward and light weight. They're 45" wide so you can go 2 wide in the truck. Throw a moving blanket on top and ride the bumpers, or lighting truss on top usually.
Click to expand...

Thats what I was initially thinking especially since Harbor Freight was running a special on moving blankets, but Mikes post got me thinking and dropping the rear point seems to be a relatively easy solution all around. I have to assemble some boxes together this weekend and see dimensionally what we are talking about.
 
Re: Line Array Carts

No need to overthink it. This looks like sensible rig.

But! IIRC that EAW flyware is aluminum (6061-T6), which has great tension numbers, but tends to distort more readily than mild steel. I would keep an eye on the pin holes.

Or I could be wrong about EAW's use of aluminum in that app.
!
 
Re: Line Array Carts

Hi there

We have carts for our V series. Rather than the speakers sitting horizontal, all angled to 0 degrees, they have an angled piece in the bottom that matches the cabinet side wall angle. The rest of the cabs just sit directly on top of the first.......

v_imdolly2.jpg

4428159.jpg


It's the single column carts pictured second that we have, but the double cart pictured shows the bottom better and how the speakers sit.

When in the cart, we only engage the front corner pins to stop the speakers sliding about, but they rest one on top of the other and so there is no compression strain on the flyware or metalwork, the actual wood of the speakers just sits one on top of the other.

The top and poles lift off with quarter turn catches so all 4 speakers can be lifted directly from the cart, and the rear flying connection can 'slide' into place as the speakers lift so a pin can be set into place ahead of time to set the angle, then a second one slid in to lock it into place once it 'catches' as it lifts and is under tension at the correct angle.

We've found it a very quick and flexible system to use.
 
Re: Line Array Carts

Kevin McDonough said:
Hi there

We have carts for our V series. Rather than the speakers sitting horizontal, all angled to 0 degrees, they have an angled piece in the bottom that matches the cabinet side wall angle. The rest of the cabs just sit directly on top of the first.......

View attachment 13796

View attachment 13797


It's the single column carts pictured second that we have, but the double cart pictured shows the bottom better and how the speakers sit.

When in the cart, we only engage the front corner pins to stop the speakers sliding about, but they rest one on top of the other and so there is no compression strain on the flyware or metalwork, the actual wood of the speakers just sits one on top of the other.

The top and poles lift off with quarter turn catches so all 4 speakers can be lifted directly from the cart, and the rear flying connection can 'slide' into place as the speakers lift so a pin can be set into place ahead of time to set the angle, then a second one slid in to lock it into place once it 'catches' as it lifts and is under tension at the correct angle.

We've found it a very quick and flexible system to use.
Click to expand...

This is, to the best of my knowledge, d&b's factory made cart system for their new speakers. It is actually quite clever in a lot of ways. Although the pole uprights can be a bit weird to attach and detach.

i do like that the cabinets rest on themselves during transport with no strain on the rigging hardware. This idea could probably be applied to all line array box system. provided that hardware allows the front point to remain attached and the boxes to come into full contact with one another without binding.
 
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