beware Posted June 21, 2006 Share Posted June 21, 2006 http://www.thomann.de/thoiw2_stairville_tr...e_prodinfo.html This seems to imply I can safely use 2 stands an 6m of bi-lite trussing. The max load on the stands is 50Kg. Does that give me 100Kg over the goalpost, or a little less? Any other opinions on this system? Cheers Link to comment Share on other sites More sharing options...
stuartglen Posted June 21, 2006 Share Posted June 21, 2006 yes but you must include the weigh of the bar/truss and the weight must be evenly distributed, if it is not then one stand will have more weight than the swl load of the stand, not a good idea. Link to comment Share on other sites More sharing options...
beware Posted June 21, 2006 Author Share Posted June 21, 2006 Thanks. Also, this truss is 32mm (correct?). So would standard 48mm hook clamps fit on it, or not? Link to comment Share on other sites More sharing options...
Simon Lewis Posted June 21, 2006 Share Posted June 21, 2006 Beware, I'm not sure of the truss diameter, but something is telling me that 100kg on a 6m span of bilite isn't too good an idea?Can you obtain proper load charts for this truss, together with proof that the stands can take the sideways load presented? Simon Link to comment Share on other sites More sharing options...
Nick S Posted June 21, 2006 Share Posted June 21, 2006 A quick :huh: gets you your loading info here (see the linked PDF). Looks OK. I can find no detailed specs on the stands they have anywhere. Thanks. Also, this truss is 32mm (correct?). So would standard 48mm hook clamps fit on it, or not? If it is 32mm, you'll need to get the appropriate hook clamp (28-32mm). The 48mm won't work well, and could potentially damage the truss. Link to comment Share on other sites More sharing options...
beware Posted June 21, 2006 Author Share Posted June 21, 2006 Thanks guys. Nick, your spec link says it's 50mm diameter anyway, so standard hook clamps should be fine. Simon, It will be holding 10 PAR64s and 6 profiles, so will be way under 100Kg anyway. Cheers again Ben Link to comment Share on other sites More sharing options...
Jivemaster Posted June 21, 2006 Share Posted June 21, 2006 Time to get the bathroom scales out! weigh everything, include a reasonable length of cable. If the load is uniformly distributed then the calcs are easy! If not then add each item of beam load and calculate the load on each stand each time. Remember that hanging cable is supported from somewhere -the truss- Set the whole rig up at ground level and check the load at each stand point with the bathroom scales! Not only must you load the stands within limits but also you must consider the truss SWL at the span you chose! Link to comment Share on other sites More sharing options...
paulears Posted June 21, 2006 Share Posted June 21, 2006 6m is a long way to go with 3 lengths of 2m. Not so much for weight loading, but for the slack in the joints. It looks like it couples with pin spigots, but not that easy to see. If it does, then you are going to have to space things out properly - but you are going to have to put the stands in about 1.5m, giving a centre span of about 3m assuming no excessive out of balance loading.http://www.thomann.de/prodbilder/stairville_traverse_4051_f32_pimx_156358.jpgNot easy to see how the ends couple - is it? Link to comment Share on other sites More sharing options...
beware Posted June 21, 2006 Author Share Posted June 21, 2006 Ah. So I couldn't put the stands at either end then... Looks like I'll be getting that install done then... Link to comment Share on other sites More sharing options...
Guest lightnix Posted June 22, 2006 Share Posted June 22, 2006 I'm not sure of the truss diameter, but something is telling me that 100kg on a 6m span of bilite isn't too good an idea?I'm no expert, but that's not a thought that inspires huge confidence in me, either; unless maybe the bulk of the weight was towards the ends of the spans, rather than all in the middle. As it is, I'm not a fan of stands when it comes to using them to support lighting (certainly any more than 3-4 lights per stand or 6-8 between two) and I never feel comfy spanning any more than 4m as it is (preferably no more than 3m) :huh: By themselves the stands maybe very stable; the problem is that punters aren't always, especially after a few drinks and all it takes is one of them to bring an already very top-heavy structure crashing down. These days, I'm starting to ask for 3-6 additional stage weights per stand, to cable-tie onto the base and lower the centre of gravity a bit (or is that a wrong thing to do? :() Link to comment Share on other sites More sharing options...
timperrett Posted June 22, 2006 Share Posted June 22, 2006 I started out with a system similar to the nature you are describing...here are some musings! Stands: I take it that the stands are safe to be used under the manufacturer's guidelines for having truss spanned between them. Not all tripods (inc our familiar friends the 3.5m wind-up Manfrottos) are suitable to have truss in between them, although obviously people still do it! I have found the Mobil-Tech SP2 tripods to be very sturdy and designed for the job. Clamps: If you were temped, it is possible (not necessarily correct) for you to only attach the bi-lite to the tripod on with a single 'Big Ben clamp'. I can recommend the Doughty two way clamp, it ensures the truss does not 'flop'! This is a must if you are over-rigging on the top cord or the lanterns are tightened up with the centre of gravity wrong on them as it causes the truss to twist. Banana: A bit of additional length on the outsides of the tripods is preferable, this then can allow you to get a really wide angle if you need it - it also is very helpful for providing a counter-weight to help reduce the banana-ring of the centre of the truss. Bolts: This mainly applies to Litestructures stock, but remember that you need to put a bolt in the cross section at the intersection of two piece on the side nearest to the bottom cord. As the top cord is under compression, the bottom is trying to split away as you add weight, thus a bolt helps to reduce tension on spigots and the aforementioned bananaring! Here endeth my musings! Link to comment Share on other sites More sharing options...
tokm Posted July 22, 2006 Share Posted July 22, 2006 Hi, been considering getting some of this truss myself (not the set, just the bi-lite) Checked with the guys at thomman, its actually 29cm! http://www.thomann.de/stairville_traverse_...nfo.html?iwid=2 :) dam, thought id found sum nice 50mm truss cheap. Tom Link to comment Share on other sites More sharing options...
mal421 Posted July 22, 2006 Share Posted July 22, 2006 To add my tuppence worth . One problem I have found using 'bylite' trussing on stands was this :- when the sapn was not loaded there were no problems but as soon as I loaded the span in didn't sag very much but it did bow quite alarmingly to the point that it became unstable . I suspect that the load at or near the centre of the span put a downward force that tried to pull the tops of the stands together . The trussing being more rigid in one plane than the other bowed rather than bent . This bowing moved the weight of centre causing the whole to become unstable . I solved the problem by building a rectangular 'trylite' gantry instead . Link to comment Share on other sites More sharing options...
Wilf dLampy Posted July 24, 2006 Share Posted July 24, 2006 Yes, the bowing of truss pulling the stands together is a common problem when using stands with truss, some manufacturers go as far as to say you shouldn't use their truss on stands- especially third party stands with fourth party adapters in the top, use the approved ground support system instead. Link to comment Share on other sites More sharing options...
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