Litec QD/QX30 & Global Truss

[ferretwrangler]

I was wondering if anyone had attempted to mate these two flavours of truss together. Some initial investigations suggest they should.

 

Im needing to create a structure for a cosmetic effect (rather than weight bearing) using a Global truss circle and litec dado cornets and straights. Its entirely a matter of will they fasten together acceptably and safely?

 

Can anybody assist?

[dunk_1984]

Global Truss is a copy of has similarities with Prolyte rather than Litec. It will mate with Prolyte, Global even use that in their marketing material. Prolyte will remind you that there's a reason it's cheaper and that you can't mix truss types and manufacturers.

 

Based on the above, Prolyte and Litec pins are a different size/shape, presumably as are Global pins.

 

You say this is for cosmetic effect, presumably if you need to mate the trusses this is going to be flown and not on the ground? The truss itself is a load and the consequences of component failure could be huge. I'd think very carefully/take advice as to whether this is a good way forward.

[ferretwrangler]

Thanks for that. Im aware of the risks involved in flying, I can deal with the elements separately and support as such, however I would have liked to physically connect the two. If this isn't do-able Ill fly the circle on its own and have the litec leg butt up to it. Would have been preferable to connect.

 

The structure is not supporting anything, it is merely eye candy.

[top-cat]

Global Truss is a copy of has similarities with Prolyte rather than Litec. It will mate with Prolyte, Global even use that in their marketing material. Prolyte will remind you that there's a reason it's cheaper and that you can't mix truss types and manufacturers.

 

Global is not a copy of Prolyte. Global uses the CCS system, which is also used by such brands as Total Fabs (XO Truss), Eurotruss, Milos, Litec... it goes on.

 

Who do you consider to be the copy cat of who?

 

I always find it interesting how companies like Milos / Litec / Global get accused of ripping off the majors, whilst it seems that Total started using the CCS after Prolyte, and started using Gusset Plates after James Thomas... but are still never considered a copy cat company? I'm not saying they are, I'm just wondering what qualifies a company as copying another's design and what is simply using an existing connection system?

 

If this isn't do-able Ill fly the circle on its own and have the litec leg butt up to it. Would have been preferable to connect.

 

 

You can still do this structurally without joining the 2 directly. You can get half-eggs for Litec which have M12 thread drilled in the flat end. You can then use an M12 bolt to attach a half coupler to the half egg, and attach one end of the truss to the perpendicular-running chords of the truss.

 

http://www.luxibel.com/images/products/4/ccs6-649.jpg

 

[ferretwrangler]

Of course! Thats a very logical solution! and I think we have some coupler eggs floating about!

 

Thanks!

[Paul Turner]

Mixing Truss from different is very bad, unless you are a qualified structural engineer and understand these things. Should anything fail, both manufactures will walk away and you could be in court explaining that you took advice from an internet forum, against the wishes of the manufactures themselves.

 

To quote Prolytes website,

"Can I combine other truss brands that suggest or say they have “Prolyte compatible” truss with Prolyte truss?

 

Some connection types, like the conical coupler or the gusset plates, have been copied by a lot of manufacturers. The various truss brands with similar connection types seem to fit onto each other. Or with a little help they are made to fit to each other.

 

Let’s have an example first:

When anyone would suggest to put the brake pads (definitely a safety involved item) of a General Motors car onto a Ford vehicle, or the other way around, the most heard reaction would be: “What kind of idiot are you?

Even though both manufacturers will not bypass their engineering departments, and the parts involved will be very much up to all quality and safety standards, mixing up both – possibly only slightly - different parts and thus manufacturing a “new” brake, could proof to be fatal in the short or long run.

Who is liable in such case?

 

Now we come back to truss. Connecting to different brands of truss is no different from the above example. Let’s say you know both manufacturers and they can provide you with all the technical information you have required. And still you would prefer to connect one brand to the other for artistic or other reasons. If failure does happen, you are liable.

 

A connection of two brands, even though it looks to be fitting quite nice is still a newly manufactured product by legal standards, and thus the ‘manufacturer’ (the guy connecting these two trusses) must do all calculations and checks needed when a new product is made.

So any inward (toe-in) or outward (toe-out) friction between the two resulting in additional bending and/or shear stresses must be checked. As well as the alloys used and the allowable stresses and the wall thickness of the connection elements, the surface area’s bearing stresses, the end-brace bending or buckling capacity, etc.

 

And now in the case that you only know the technical details of only one, and ‘somebody’ tells you that it is OK to join this to another brand. Are you able to analyze this into the very details that are legally needed? If not, you can predict the reaction of this particular person after failure has occurred: he will deny ever having said so. Make sure you get it in writing, and in such a way that all liability goes his way as well.

 

That Prolyte specifically warns for inter-connecting different types of truss in general term is not for our safety, but for yours. Our industry benefits by improving its safety, not by ignoring warnings, even though they might look commercially motivated at first impression."

 

For the small cost of cross renting the correct bits, its just not worth the risk these days.

[dunk_1984]

Global is not a copy of Prolyte. Global uses the CCS system, which is also used by such brands as Total Fabs (XO Truss), Eurotruss, Milos, Litec... it goes on.

 

I am not referring to the CCS, but the design. I realise that the information may be bias given that it came from Prolyte, however their view is that people have copied their truss design and are claiming that it is Prolyte compatible. Hence Paul's quote from Prolyte disagreeing with this point.

[top-cat]

I don't disagree at all with Paul that mixing truss brands is bad. Truss is a reasonably special material in that the connections have to be sufficiently strong so that the loading data for truss remains constant regardless of how many physical pieces it's made of. As soon as a stick of truss, comprising more than one brand, is present - any data that existed for one or the other is completely invalid.

 

That said I'm not against companies advertising as kit being "Prolyte Compatible". Plenty of manufacturers of plenty of products openly suggest compatibility with other manufacturers systems. It depends what you're mixing - 10m stick of truss which is half Prolyte and half Global... yes that is not something to use when you're lifting. HOWEVER, Making a 2m truss tower for a couple of par cans, using a global stick and a Prolyte base plate? I don't see a problem myself. Accessories is one area where it can be reasonable to mix - providing you're sensible about it.

 

I am interested as to how you determine that Global's design copies Prolyte, but Total's 'XO' design or Milos' QuickTruss doesn't - they are extremely similar. Or how the 20.5" GP trusses offered by Total or Tomcat which seem to have a striking resemblance to the A-Type truss produced by James Thomas. Or would we just never associate such brands with plagiarism because they are reputable companies with plenty of clearly original products; and don't sell almost exclusively on Thomann like Global do...?

 

I'm not aiming this personally at you or anything, but it's a general point I make. Plenty of people slate Milos as being a hobbyist truss for mickey mouse AV companies and cheap stage companies. Yet their engineering team are perfectly credible professionals, their welding is TUV certified, and they've been commercially successful enough to take on brands like Litec and Tomcat who have a strong and reputable standing in this industry.

 

It is inevitable that there will be more truss manufacturers than ways to join trusses together. But that doesn't mean they are 'copying'. Equally I chatted to some Clay Paky people at PLASA, and how there is clearly a difference between other brands producing a sharp, clean beam fixture using a Platinum 5R lamp that has it's own thought-out way of working and feature set; and the brands who copy the Sharpy down to it's dimensions and menu layout. And the former they don't really consider a bother... it's not as if they were the first company to offer 700W moving head spots... but they developed one with it's own feature set and gave it a name and made it a very popular model. Doesn't make it a copy. But there will always be companies who try to bad-press other manufacturers to attempt to boost their own sales. Unfortunately these attempts can often be short sighted, since the kind of people who are driven to buy a cheaper product are often set on it because of the price more than it's reputability anyway...!

[dunk_1984]

I have never had a bad word to say about any of the listed manufacturers and have worked with them all.

I may have started out a little over defensive, this is down to information supplied by Prolyte, as I said, potentially bias. Also from constantly having to tell a previous employer that it was not acceptable to mix and match truss.

 

I'm not aiming this personally at you or anything, but it's a general point I make.

 

I appreciate that.

[top-cat]

Also from constantly having to tell a previous employer that it was not acceptable to mix and match truss.

 

 

Sure, and I agree - my point was simply that I am sure most manufacturers of systems which have been used by other companies will say they have been 'copied', and that copies are 'inferior'.

 

But then Prolyte make folding truss. Their design? No. Would they like it if somebody else called them copy cats? I doubt it!