rstech Posted August 22, 2012 Share Posted August 22, 2012 Hi everyone, So I've used booms for generics, but never for movers. I was wondering if it were possible with small movers, like Mac 250s. I've done a quick drawing to show you what I mean.. Thanks in advance (: http://oi45.tinypic.com/k51qwp.jpg Link to comment Share on other sites More sharing options...
Young Johnstone Posted August 22, 2012 Share Posted August 22, 2012 I've done this with 250's loads of times, however I've always used truss as my tower, not scaff! And had a well weighted tank trap / base. Link to comment Share on other sites More sharing options...
niclights Posted August 22, 2012 Share Posted August 22, 2012 There's no reason why not, assuming it can take the weight/won't fall over etc. etc. Link to comment Share on other sites More sharing options...
paulears Posted August 23, 2012 Share Posted August 23, 2012 Not so much taking the weight, but handling the shift in CoG when they both swing at the same time. If they both did a reset and the boom was only supported on the tank trap, then the sideways force could be considerable. If the boom is fixed, then I'd probably no bother with the horizontal component at all, and just mount them to the vertical pole - which would give a wider range of movement too. Link to comment Share on other sites More sharing options...
Pat Posted August 23, 2012 Share Posted August 23, 2012 Base plate should have a good weight and size.We have 80kg base plates 1m dia. With two MH's it is in my opinion not stable therefor we put only one MH on that truss. Link to comment Share on other sites More sharing options...
Ynot Posted August 23, 2012 Share Posted August 23, 2012 I'd say the answer is "It depends". On the size of the base and weight you're able to sit on it.On the type and weight of movers (this time maybe Mac 250, but next time...?)On how high you plan hang the heads - the higher you go the poorer the centre of gravity will be and the movement will have increasingly more of an effect on the upright, meaning you'd need far more weight on the base to counter that potential. Also the higher you go the more chance you have of the upright literally swaying regardless of the weight on the base... Personally I'm not a fan of using tank traps like this, though I have seen it done successfully within limits. The last time I saw it however the traps were bolted to the deck. (And no, I wouldn't suggest screws to do that as with too much movement there's a high risk of screws coming adrift) Link to comment Share on other sites More sharing options...
jonathanhill Posted August 23, 2012 Share Posted August 23, 2012 If I had to do this, I would tie a line from the grid to the boom, get the guys in the grid to lift the boom about two stage weights off the grid and tie off. Then I would stand on the tank trap and coach bolt it to the floor with something like an M10x70mm coach screw. Probably with an impact wrench. The way you have arranged the movers, i.e. one upstage and one downstage is the best way of distributing weight. If the movers were anything other than 250's or were going higher than around 3m, I would want to use tower truss and a suitable baseplate, screwed to the floor, with a safety line from the grid. Link to comment Share on other sites More sharing options...
gyro_gearloose Posted August 23, 2012 Share Posted August 23, 2012 If I had to do this, I would tie a line from the grid to the boom, get the guys in the grid to lift the boom about two stage weights off the grid and tie off. Then I would stand on the tank trap and coach bolt it to the floor with something like an M10x70mm coach screw. Probably with an impact wrench. The way you have arranged the movers, i.e. one upstage and one downstage is the best way of distributing weight.Bear in mind that if you do this on some wooden stages, you will lift the stage up! There are much better ways of putting movers on booms - truss with proper floor plates, for one. Link to comment Share on other sites More sharing options...
paulears Posted August 23, 2012 Share Posted August 23, 2012 I've seen this the standard boom support technique in many big venues, where the flyrail is in just the right position. Always seems a bit odd, but it does seem to work ok- but I like the bit about the floor - it's not good to see the floor surface lift up! Link to comment Share on other sites More sharing options...
ScottishCol Posted August 24, 2012 Share Posted August 24, 2012 Hi everyone, So I've used booms for generics, but never for movers. I was wondering if it were possible with small movers, like Mac 250s. I've done a quick drawing to show you what I mean.. Thanks in advance (: http://oi45.tinypic.com/k51qwp.jpg What's so different from using a standard T-bar on windupstand (assuming OP's base is wide enough)? Link to comment Share on other sites More sharing options...
Nicktaylor Posted August 24, 2012 Share Posted August 24, 2012 Not so much the base size? But the weight rating would be pushing it for anything but the most expensive stands. Source Manfroto listing. As an aside I did wonder if you can rig a mac on a large TV spigot and use it "right way up" on top of a stand. At least the forces due to the head moving would be right over the vertical, especially the non moving very heavy base unit Link to comment Share on other sites More sharing options...
ScottishCol Posted August 24, 2012 Share Posted August 24, 2012 Not so much the base size? But the weight rating would be pushing it for anything but the most expensive stands. Source Manfroto listing. As an aside I did wonder if you can rig a mac on a large TV spigot and use it "right way up" on top of a stand. At least the forces due to the head moving would be right over the vertical, especially the non moving very heavy base unit Is there a definitive answer or rule of thumb as to how much to add for a moving head as oposed to generics? Link to comment Share on other sites More sharing options...
Ynot Posted August 24, 2012 Share Posted August 24, 2012 The centre of gravity on a decent braced stand is going to be higher, and the footprint of that stand (by necessity) would be larger, and hence if used properly then the stability of a stand will be much greater. Link to comment Share on other sites More sharing options...
jonathanhill Posted August 24, 2012 Share Posted August 24, 2012 I would go with a boom, as securing a top point on a stand could be problematic. Not to mention the increased floor area required by a stand. Not always welcome, or indeed, possible in a more compact venue. Link to comment Share on other sites More sharing options...
Dirk Posted August 24, 2012 Share Posted August 24, 2012 Just a few thoughts having read the above. 1) Keep your horizontal elements as drawn, or with a T bar. Automated luminares work better when the base is horizontal, are easier to program, less bearing wear, and often quieter 2) Forces from resetting etc are minimal, compared with the far bigger problem of people bumping into it, wheeling things into it, leaning on it, hanging coats on it, etc etc. So... Keep the number of luminaures sensible, a good base size, well loaded. And a safety from the top of the thing to the sky, just in case is always a wise move. If it wobbles and looks unstable, it probably is! Just my thoughtsD Link to comment Share on other sites More sharing options...
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