adenbeckitt Posted September 1, 2015 Share Posted September 1, 2015 Hi, I have two Fantek T-106 Tower lifts. (https://www.thomann....lift_200_kg.htm)On this I attach 4x 2m square trussing (GLOBAL TRUSS F34200) I am using this to fly a LED video screen. I have worked out all the weights and everything adds up. However, when I start to elevate the lift, the tower sections are leaning forward (note, the tower is not coming off the floor, it is the individual telescopic sections that are leaning). This is obviously because I have all the weight on the front bar of the square trussing.Is this a problem? if so, how can it be solved? other than counterweighting the back pole of the trussing (as this would be too much weight for the lifts.)If counterweights are indeed the only way, then I'll have to get some stronger lifts. Thoughts? :) Link to comment Share on other sites More sharing options...
boatman Posted September 1, 2015 Share Posted September 1, 2015 Could you move the truss back so that the centre of mass is directly above the tower sections? Alternatively, if the truss has to be symmetrically located, change it to triangular truss and hang the load from the top pipe which should be in line with the centre of the tower sections.. Link to comment Share on other sites More sharing options...
sameness Posted September 1, 2015 Share Posted September 1, 2015 If you are hanging a screen, are you using existing hardware to clamp the the truss, or are you using spans/steels? Personally I would only use the tower lift to actually lift something into place and then secure it with something else. What screen are you using and what size is it? Link to comment Share on other sites More sharing options...
adenbeckitt Posted September 1, 2015 Author Share Posted September 1, 2015 Thanks for the replies so far. Didn't expect to hear from anyone so soon :)Could you move the truss back so that the centre of mass is directly above the tower sections? Alternatively, if the truss has to be symmetrically located, change it to triangular truss and hang the load from the top pipe which should be in line with the centre of the tower sections.. I had this idea myself but my truss adapters for the top don't move that far. I'm looking at some others now which might allow me to do this. Well, it won't be able to be directly centre but very close! If you are hanging a screen, are you using existing hardware to clamp the the truss, or are you using spans/steels? Personally I would only use the tower lift to actually lift something into place and then secure it with something else. What screen are you using and what size is it? I am using the clamps that came with the unit. Unfortunately, with the venues we are doing it is not viable to secure it with anything else. Well, the venues either have motorised fly bars that can take the weight, or they don't. When they don't we use the tower lifts. The screen is from Huasun (Rubik 6) and is about 5.5m wide/3m tall. http://I.imgur.com/ujEzzFKl.jpg We wanted to have it higher, but had to settle with it being just cm from the floor as we noticed the leaning and didn't want to risk it. Link to comment Share on other sites More sharing options...
empyfree Posted September 1, 2015 Share Posted September 1, 2015 You've really got to get that weight centred on the stand as others have said. I'm amazed that isn't mentioned in the user guidance for the stands, it should be! Link to comment Share on other sites More sharing options...
adenbeckitt Posted September 1, 2015 Author Share Posted September 1, 2015 You've really got to get that weight centred on the stand as others have said. I'm amazed that isn't mentioned in the user guidance for the stands, it should be! Nope, it isn't, but it's fairly obvious... well, it was once I saw it lean. Link to comment Share on other sites More sharing options...
the kid Posted September 1, 2015 Share Posted September 1, 2015 Assuming you are using these that small change is lots, we use them quite a bit for screens etc and never much of an issue, remember you can adjust the level a bit help stop the lean . Link to comment Share on other sites More sharing options...
johnhuson Posted September 1, 2015 Share Posted September 1, 2015 How are you attaching the screen to the truss? If you are clamping to one chord (bar) of the truss then you will find it difficult to centre the load. Link to comment Share on other sites More sharing options...
trussmonkey Posted September 2, 2015 Share Posted September 2, 2015 if you are having trouble centring the load with the exisiting hardware you have I would rent some round slings and rigging screws etc. That will get your load centred and the rigging screws will be able to adjust the screen to keep it nice and level. those items should be pretty cheap and easy to rent. Link to comment Share on other sites More sharing options...
adenbeckitt Posted September 2, 2015 Author Share Posted September 2, 2015 Could you move the truss back so that the centre of mass is directly above the tower sections? Is this what you are suggesting? Moving the clamps on the truss adaptor back as far a possible to centre the load bearing section of the truss in the centre of the lifts? (the red circle indicating where the screen is to be clamped)http://I.imgur.com/O0nz9Qdl.jpghttp://I.imgur.com/i8HsuyCm.jpg Would it cause any problems off setting the truss like this? How are you attaching the screen to the truss? If you are clamping to one chord (bar) of the truss then you will find it difficult to centre the load. Yes, I am clamping to one bar of the truss using these.http://I.imgur.com/QwQuRNAl.jpg Link to comment Share on other sites More sharing options...
boatman Posted September 2, 2015 Share Posted September 2, 2015 Could you move the truss back so that the centre of mass is directly above the tower sections? Is this what you are suggesting? Moving the clamps on the truss adaptor back as far a possible to centre the load bearing section of the truss in the centre of the lifts? (the red circle indicating where the screen is to be clamped)http://I.imgur.com/O0nz9Qdl.jpg.. Would it cause any problems off setting the truss like this? Yes. that's exactly what I meant. Even better would be to use triangular truss so that the top bar can be located directly over the tower. Edited: to remove unnecessary diagrams. Link to comment Share on other sites More sharing options...
MarkPAman Posted September 2, 2015 Share Posted September 2, 2015 Even better would be to use triangular truss so that the top bar can be located directly over the tower. Or hang it from short lengths of tube fixed at right angles to the truss - probably cheaper than replacing the whole thing. Link to comment Share on other sites More sharing options...
adenbeckitt Posted September 2, 2015 Author Share Posted September 2, 2015 Even better would be to use triangular truss so that the top bar can be located directly over the tower. The problem with that is that I couldn't then attach the bar that holds the screen to the top chord of the truss;http://I.imgur.com/QwQuRNAl.jpg I am now thinking of doing something like this;http://I.imgur.com/g1yX6CBl.jpg Does anyone know of something like this but flat? Link to comment Share on other sites More sharing options...
boatman Posted September 2, 2015 Share Posted September 2, 2015 http://I.imgur.com/QwQuRNAl.jpg Can you turn the clamps on that bar through 90 degrees? If so then MarkPAman's suggestion is the best compromise to get the centre of mass over the towers. Link to comment Share on other sites More sharing options...
adenbeckitt Posted September 2, 2015 Author Share Posted September 2, 2015 Can you turn the clamps on that bar through 90 degrees? If so then MarkPAman's suggestion is the best compromise to get the centre of mass over the towers. Yes, I can, but they need to be parallel to the trussing as the screen slides into it. I think doing something like I suggested in my previous post would be best? (http://I.imgur.com/g1yX6CBl.jpg) Link to comment Share on other sites More sharing options...
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