slipstream Posted November 18, 2007 Share Posted November 18, 2007 We own a similar system - Chinese I am afraid to say and only considered the DMX version for about 3 sec - there is a lot of heat from them and while the timing would be nice from a desk, it's not worth the risk. Sam Link to comment Share on other sites More sharing options...
Ike Posted November 18, 2007 Share Posted November 18, 2007 I can't help but wonder how many of the people suggesting DMX should never be used would be up in arms if I suggested ladders shouldn't be used to focus lanterns as that too can be unsafe in certain circumstances. If the area surrounding the device is clear whenever it's powered up or armed (as the manufacturers instructions clearly state) it doesn't matter if you desk goes screwy and all your flame throwers get stuck on high, it's still safe. It's all very well people sitting back and saying it should be done manually but have any of you actually tried synchronizing half a dozen similar effects to different beats in a drum roll or a very precisely timed lighting effect? For a start too much of the firers concentration is usually taken up by getting the timing right so you need someone else on a dead mans handle which means you need at least one extra competent person to start with. The you have to get the firer, controller and cabling into an appropriate place to accept a visual cue which can take up valuable space and get in the way. All in all it can be a bit of a ball ache. I'm not going to get into another rant about Chinese being used a a synonym for crap as I think I've done that one to death but if you're at all unsure of the quality of potentially dangerous equipment why on earth are you using it? Link to comment Share on other sites More sharing options...
smf Posted November 18, 2007 Share Posted November 18, 2007 Being primarily a firework display company but also providing stage pyro I am also very worried about DMX controlled pyro effects. The most important rule with any effect is unless the operator can see the effect and ensure the area is clear it shouldn't be fired at all. Therefore putting that in the hands of a computer program with the unknown factor of performers on the stage it is a complete nightmare and shouldn't be allowed.Do this and someone WILL GET SERIOUSLY HURT. Mick Link to comment Share on other sites More sharing options...
dbuckley Posted November 18, 2007 Share Posted November 18, 2007 Computers can - and do - fire pyro, flames and other unsafe sh*t, and move scenery and structures all the time, and often using dodgy protocols like DMX512, but, and it's a massive but, you have to have the right safety control systems in place to enable this stuff to be used safely irrespective of any failure in the control system. It's the latter bit that causes trouble and expense, as it has to be done right, and requires people. It's no different to machine tools; computers (in the form of PLCs) make decisions all the time, and do dangerous things, but the emergency stop system has to operate independently of the control system, for exactly the same reason - all control systems fail. Link to comment Share on other sites More sharing options...
MFX1 Posted December 5, 2007 Share Posted December 5, 2007 Despite the fact that DMX is not a suitable protocol for controling hazardous applications have you noted the safety distances, 3Mtr sideways which is effectively a 6Mtr Dia. circle and 6 - 8 Mtr height, you're going to need a seriously big venue to use ONE safely. That's some serious ass covering they're doing. I was recently involved in designing and providing the flames for the Bacchae in Edinburgh http://www.flickr.com/photos/23129101@N00/...57601334088461/ The total flame height was around 12 feet and the performers were about 2M away but we had labrats (i.e. me) and thermocouples all over the set and in the grid and it was safe closer than that. Oh and no it didn't use DMX because at some points in the show performers were actually standing and sitting on the flame bars there's no way I would have trusted that to a busy lighting OP, the effect had a dedicated operator and dedicated control system. Link to comment Share on other sites More sharing options...
peternewman Posted December 6, 2007 Share Posted December 6, 2007 I'm going to have to side with Ike here. Assuming you are using a dead mans handle, how is getting the DMX to press the buttons and using the DMH as the equivalent of a keyswitch on a normal pyro unit any different. Yes the DMX may accidentally fire the units at the wrong time, but equally you could press the fire button early. Admittedly you would probably need a DMH per effect or group, but as with Ike I fail to see how it can be more dangerous than complete manual firing. Link to comment Share on other sites More sharing options...
MFX1 Posted December 6, 2007 Share Posted December 6, 2007 Question is though does the unit come with, or even have a facility for a dead mans handle? I suppose you could simply break the DMX connection but that would mean the unit being on it's own universe (and as long as they haven't implemented the feature where a unit holds at it's last state if DMX is lost, that would be a bad thing!) BTW anyone know why it needs 3 DMX channels? Link to comment Share on other sites More sharing options...
dave_m Posted December 6, 2007 Share Posted December 6, 2007 Question is though does the unit come with, or even have a facility for a dead mans handle?Even if it didn't, what about putting it/them on a separate circuit and installing a push to break switch? Link to comment Share on other sites More sharing options...
david.elsbury Posted December 6, 2007 Share Posted December 6, 2007 Simply breaking the DMX line is no way to guarantee that no data will be transmitted. For example, when unplugging the data, it could send a spurious pulse to the flamejets, and they turn on... and then hold that data until told what to do next, which won't happen until the data is plugged in again! Link to comment Share on other sites More sharing options...
peternewman Posted December 6, 2007 Share Posted December 6, 2007 Yes admittedly my post is on the assumption it has a dead mans handle. If it doesn't then I'd probably be wary of it, whether fired via DMX, another protocol or traditionally. Link to comment Share on other sites More sharing options...
MFX1 Posted December 6, 2007 Share Posted December 6, 2007 BTW anyone know why it needs 3 DMX channels?Ah found this :scharfZündungflammen zeitWhich roughly translates as :-Sharply (fireball ?)Ignition flare So you need one channel to start the ignition and then Flares and Fireballs are on 2 seperate channels I guess. I suspect it's simple on/off, a unit with DMX controlled flame height I suspect would cost a fair bit more.Simply breaking the DMX line is no way to guarantee that no data will be transmitted. For example, when unplugging the data, it could send a spurious pulse to the flamejets, and they turn on... and then hold that data until told what to do next, which won't happen until the data is plugged in again!Hence my comment "and as long as they haven't implemented the feature where a unit holds at it's last state if DMX is lost, that would be a bad thing!" Now I'm no expert on lighting but AIUI many lights do this, of course it's easy to design so that the unit fails safe when DMX is lost or even if spurious random data is recieved and I'm sure they would have done this (hopefully !) Howver is there a possibility a DMX repeater of some sort could latch up and keep the flames going even if they've been told to shut down by the desk? Link to comment Share on other sites More sharing options...
mikienorth Posted December 7, 2007 Share Posted December 7, 2007 Erm...Been there, done that (Flames via DMX) System was adapted by the makers to have an artistic licence DMX relay replace the control circuits for the flame jets. Ignition still had to be carried out by an operator, lighting the pilot light around 2 minutes prior to the effect. The control supplied was fitted with a dead man's switch which interrupted the main feed gas flow to the heads. This was replaced by a series circuit of three dead man's switches (momentary push to make) so if one person was concerned the effect stopped.The effect was fired from one sub, not the main go button, and only loaded to that sub at the start of the number. Deadmans were, in control (held by the playback operator), on stage at the closest point the SM could get and remain concealed with a clear view, and in line with the effect in an elevated position. No problems experienced, I'd happily do it again with similar controls. All involved were trained in the system, and the MS/RA was satisfactory due to the controls above. I've seen this sort of stuff fired via timecode from an HDD playback, again with deadmans controls, is this not worse than DMX? Outdoor displays (Kilos of NEQ) are fired via timecode, and once these things are lit you can't stop them. with the gas system I used, the bottles were remote, and could be shut down by pulling a plug, disconnecting the main solenoids to both pilot and main lines at the cylinders. Can't do that with a toppled shell rack... I don't like the thomann box mind, self contained aerosol? can't get to it to put it out. Remote propane is better. Link to comment Share on other sites More sharing options...
adamharman Posted January 2, 2008 Share Posted January 2, 2008 but equally you could press the fire button early Or switch on the wrong output on a LeMaitre Pyroflash controller Link to comment Share on other sites More sharing options...
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