Return-Path: X-Processed-By: Virex 7 on prxy.net X-Real-To: stagecraftlist [at] theatrical.net Received: by prxy.net (CommuniGate Pro PIPE 4.2.5) with PIPE id 4841964; Sat, 30 Oct 2004 03:00:52 -0700 X-ListServer: CommuniGate Pro LIST 4.2.5 List-Unsubscribe: List-ID: Message-ID: From: "Stagecraft" Sender: "Stagecraft" To: "Stagecraft" Precedence: list Subject: Stagecraft Digest #179 Date: Sat, 30 Oct 2004 03:00:42 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Disposition: inline X-Spam-Status: No, score=-4.7 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.0.1 X-Spam-Checker-Version: SpamAssassin 3.0.1 (2004-10-22) on prxy.net X-Spam-Level: X-TFF-CGPSA-Version: 1.4f2 X-prxy-Spam-Filter: Scanned For info, archives & UNSUBSCRIBE, see --------------------------------------------------- Stagecraft Digest, Issue #179 1. Re: Dave Vick by "Paul Guncheon" 2. Re: Dave Vick by "Randy Whitcomb" 3. RATS by usctd [at] columbia.sc 4. Re: RATS by "Tony Deeming" 5. New lamps available for trade by Mike Voytko 6. Verlock by "richard j. archer" 7. Re: Verlock by "Joe Golden" 8. Re: cold water ground by FrankWood95 [at] aol.com 9. Re: cold water ground by Jerry Durand 10. Re: Verlock by Greg Bierly 11. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by CB 12. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by CB 13. Re: Bizarre Multiple Catastrophic Truss Failure by CB 14. Re: Dave Vick by Stuart Wheaton 15. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by FrankWood95 [at] aol.com 16. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by FrankWood95 [at] aol.com 17. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by Stuart Wheaton 18. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by Jerry Durand 19. Re: Bizarre Multiple Catastrophic Truss Failure by Bill Sapsis 20. Re: Bizarre Multiple Catastrophic Truss Failure by Jerry Durand 21. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by Stuart Wheaton 22. Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look by "Cyr, Dale" 23. Re: Fresnel Replacement Recommendations by "Mike Marriott" 24. Re: Fresnel Replacement Recommendations by Greg Persinger 25. Re: Fresnel Replacement Recommendations by David Duffy 26. Re: cold water ground by StevevETTrn [at] aol.com 27. The Bright Blue Mailbox Suicide Note by Mat Goebel *** Please update the subject line of your reply to use the subject *** line of the message you are replying to! Please only reply to *** one message subject in each reply. ---------------------------------------------------------------------- Message-ID: <002801c4bdc2$405d2dd0$0202a8c0 [at] MyLastPC> From: "Paul Guncheon" References: Subject: Re: Dave Vick Date: Fri, 29 Oct 2004 04:19:06 -1000 The question was asked a few weeks ago but I didn't see an answer, so I'll ask again: Where's Dave Vick? Laters, Paul "Cobblers!" said Tom at last. ------------------------------ Message-ID: <001201c4bdc4$76f19500$0300a8c0 [at] c430576a> From: "Randy Whitcomb" References:

Subject: Re: Dave Vick Date: Fri, 29 Oct 2004 08:34:57 -0600 He's been posting on RATS recently. ------------------------------ Message-ID: <2165.129.252.241.105.1099065830.squirrel [at] webmail.columbia.sc> Date: Fri, 29 Oct 2004 12:03:50 -0400 (EDT) Subject: RATS From: usctd [at] columbia.sc Pardon the ignorance, but what is the RATS group? -- Eric Rouse TD-University of SC, Columbia Freelance Foyboy ------------------------------ Message-ID: <1b5701c4bdd0$e8646f80$0a01a8c0 [at] Tony> From: "Tony Deeming" References: Subject: Re: RATS Date: Fri, 29 Oct 2004 17:03:59 +0100 Usenet newsgroup. rec.arts.theatre.stagecraft. HTH TD ----- Original Message ----- From: To: "Stagecraft" Sent: Friday, October 29, 2004 5:03 PM Subject: RATS > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > Pardon the ignorance, but what is the RATS group? > -- > Eric Rouse > TD-University of SC, Columbia > Freelance Foyboy > > > ------------------------------ Message-Id: <057B12B6-29C8-11D9-A06D-003065864964 [at] nyu.edu> From: Mike Voytko Subject: New lamps available for trade Date: Fri, 29 Oct 2004 12:31:44 -0400 I have a stock of the following new lamps, and no fixtures to put them in. If anyone is interested in a trade, please contact me off-list. FEL 1000 watt EGJ 1000 watt, med. prefocus, for 14" scoop BVW 2000 watt, mog. prefocus, for 8" Fresnel / beam proj. Thanks, Mike V. -- Mike Voytko Lighting & Sound Supervisor TSOA Theatrical Production New York University ------------------------------ Message-Id: In-Reply-To: References: Date: Fri, 29 Oct 2004 12:56:15 -0400 From: "richard j. archer" Subject: Verlock List members; Anybody out there ever use Verlock from Ver Sales? http://www.versales.com a sort of"gripple" type device that's rated Thanks Dick Archer TD Cornell U ------------------------------ Subject: RE: Verlock Date: Fri, 29 Oct 2004 10:16:46 -0700 Message-ID: From: "Joe Golden" We use them all the time. Contact me off list for more details. Joe > Anybody out there ever use Verlock from Ver Sales? =20 http://www.versales.com a sort of"gripple" type device that's rated Thanks Dick Archer TD Cornell U ------------------------------ From: FrankWood95 [at] aol.com Message-ID: <1d5.2e1d2e22.2eb3d6f3 [at] aol.com> Date: Fri, 29 Oct 2004 13:25:07 EDT Subject: Re: cold water ground In a message dated 29/10/04 05:01:48 GMT Daylight Time, dale [at] cybercom.net writes: > The bottom line is that you want all the grounds in the audio > system to come from one single common electrical connection > to the earth, and with low enough resistance in all your ground > conductors that there is no momentary differences in the > ground reference in different points in your system. As Dale rightly says, it is a thick chapter in the book. Let me amplify a little. The very best way is to connect the earth connections of all the audio system directly to the earth spike. They should not share the conductor with any other earth connection at all. If you look at a circuit diagram of an earth distribution system, You will see that it closely resembles a 'star mixer'. The inpedances are two or three orders of magnitude lower than usual, but they are still there, and in proportion. This is a counsel of perfection. And, it depends on the nature of the mains wiring and of the audio system. If the latter is properly balanced, that is to say, never uses the earth connection as a part of the signal path, there will be less trouble. This can be expensive and difficult. UK and US customs and practices are different. When I worked for the BBC, building big TV studios, it was customary to leave off the sound earths until the last moment, and to connect a battery and buzzer betwen the sound earth and what we called the 'dirty earth'. If it went off, you stopped wiring, undid the last step, and found out why. Frank Wood ------------------------------ Message-Id: <6.1.2.0.0.20041029103917.022c51d0 [at] localhost> Date: Fri, 29 Oct 2004 10:49:12 -0700 From: Jerry Durand Subject: Re: cold water ground In-Reply-To: References: At 10:25 AM 10/29/2004, you wrote: >UK and US customs and practices are different. When I worked for the BBC, >building big TV studios, it was customary to leave off the sound earths >until the >last moment, and to connect a battery and buzzer betwen the sound earth and >what we called the 'dirty earth'. If it went off, you stopped wiring, >undid the >last step, and found out why. The biggest problem I've seen people have with grounding (both for noise and static control) is understanding that there is nothing special about earth ground. The key is to have EVERY piece of equipment tied to the SAME ground, whatever that is. So, you can still GROUND things in a spacecraft. An electronics test floor that I managed had a terrible time with ground loops, we were blowing out serial ports and other parts of testers all the time. When we were bringing in more computers and laser systems (1200W pulsed cutting lasers), I convinced the powers to allow me to have the entire floor rewired. I had a long talk with the head electrician and convinced him to run a very heavy ground wire to every outlet/equipment connection on the floor and tying all the grounds together in our sub-panel and then a run "poor but legal" ground from there to the main switch panel (which supplied automated arc welders and other heavy equipment elsewhere in the building) while running . After he was done we never had a ground loop problem again. A different problem on the same floor was the night cleaning crew found out there were nice power strips inside the back of all these computer cabinets and started plugging their floor waxers in there. We added locks to the rear doors on all the racks after that. ---------- Jerry Durand Durand Interstellar, Inc. 219 Oak Wood Way Los Gatos, California 95032-2523 USA tel: +1 408 356-3886 fax: +1 408 356-4659 web: www.interstellar.com ------------------------------ In-Reply-To: References:

Message-Id: From: Greg Bierly Subject: Re: Verlock Date: Fri, 29 Oct 2004 15:27:01 -0500 > Anybody out there ever use Verlock from Ver Sales? Yup. They worked well for me. I need to get around to buying a few dozen more. (I wish the locking nut were captive) There was some discussion about them on the list a year or two ago. I am not sure if the archives are up or not but IIRC there were some questions as to their reliability under non-static loads. Greg Greg Bierly Technical Director Hempfield HS ------------------------------ Message-Id: <3.0.6.32.20041029134444.0197de68 [at] pop.west.cox.net> Date: Fri, 29 Oct 2004 13:44:44 From: CB Subject: RE: Bizarre Multiple Catastrophic Truss Failure / more pix, second look >evidence of what I'm calling "sitting on top of" the >member, >as opposed to fully engaging it. >(I think somebody ealier called this a "cold weld".) Now, I'm just a novice welder, steel only, and MIG only at that, butI do solder a great deal. Questions: 1. Does "cold weld" equate to "cold solder joint"? 2. What does "penetration" mean in an aluminium weld? 3. If cold welds were the problem, wouldn't the welds be peeling away from the work, as opposed to the weld actually breaking as they appear to have done , at least to my eye, in the photos? 4. Isn't aluminum welding more like hot gluing than steel welding? (Remember, I'm somewhat ignorant of the process) Chris "Chris" Babbie Location Sound MON AZ Delete key training and post trimming done by appointment. Rates negotiable, will trade for typing lessons/ADD treatment... ------------------------------ Message-Id: <3.0.6.32.20041029135053.0197de68 [at] pop.west.cox.net> Date: Fri, 29 Oct 2004 13:50:53 From: CB Subject: RE: Bizarre Multiple Catastrophic Truss Failure / more pix, second look >surely there is something going on here besides the laws of averages >building up >and colliding together on the same morning... While I would also tend to lean that way, devil's advocate would have to say that the word 'coincindent' came from somewhere. Once implies possibility. Twice implies probability. Tthree times implies proof. Thereby coining the phrase, "Third time's the charm". Chris "Chris" Babbie Location Sound MON AZ Delete key training and post trimming done by appointment. Rates negotiable, will trade for typing lessons/ADD treatment... ------------------------------ Message-Id: <3.0.6.32.20041029135503.0197de68 [at] pop.west.cox.net> Date: Fri, 29 Oct 2004 13:55:03 From: CB Subject: Re: Bizarre Multiple Catastrophic Truss Failure >For the enlightenment of us sound guys: Another way to state this is: >A connection point must always be inside 2 pick points. Is this correct? And against my better judgement, following the saying that a little knowledge is a dangerous thing, let me also learn more about this rigging thing. If it is correct, whymust they be inside? It seems to me that ten foot of truss hanging on the end of a connection (given and even weight distribution) three feet from the pick point receives less stress that any of the other connections that are farther from the pick point, but inside the span. Nosy lil sound guys wanna know.. Chris "Chris" Babbie Location Sound MON AZ Delete key training and post trimming done by appointment. Rates negotiable, will trade for typing lessons/ADD treatment... ------------------------------ Message-ID: <4182BD6A.9030404 [at] fuse.net> Date: Fri, 29 Oct 2004 18:00:10 -0400 From: Stuart Wheaton Subject: Re: Dave Vick References:

In-Reply-To: Paul Guncheon wrote: > > The question was asked a few weeks ago but I didn't see an answer, so I'll > ask again: > > Where's Dave Vick? I got a note from him. Basically, life, wife, and work are conspiring against his available free time, so he's not here, but he does find time to read RATS a little. Stuart ------------------------------ From: FrankWood95 [at] aol.com Message-ID: Date: Fri, 29 Oct 2004 18:00:14 EDT Subject: Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look In a message dated 29/10/04 21:45:36 GMT Daylight Time, psyd [at] cox.net writes: > Now, I'm just a novice welder, steel only, and MIG only at that, butI do > solder a great deal. > Questions: > 1. Does "cold weld" equate to "cold solder joint"? > 2. What does "penetration" mean in an aluminium weld? > 3. If cold welds were the problem, wouldn't the welds be peeling away from > the work, as opposed to the weld actually breaking as they appear to have > done , at least to my eye, in the photos? > 4. Isn't aluminum welding more like hot gluing than steel welding? Answers. 1. Cold joints, whether welds or with solder, are unsatisfactory. Solder joints rely on 'wetting' the two surfaces to be joined with the solder. This is why aluminium and stainless steel are such pigs. Both carry a layer of oxides. While it accounts for their corosion resistance, it makes them a real pain to solder. 2. As with all welds, it means that the alloying process has penetrated deep enough into the material to achieve strength in the joint. A proper weld is solid metal from one side of the joint to the other. The exact composition of the metal changes as you go through the joint. 3. Probably, much as a 'dry' solder joint does. 4. No. All welds involve melting the base material on both sides of the joint. Some involve supplying a filler material, and all involve removing any oxidation, either natural or caused by the heat involved. You say that you're an MIG welder, on steel. Ite IG bit stands for 'Inert Gas', and is to prevent any oxide films from forming. The flux layer on an old-fachioned arc welding rod has the same function. Frank Wood ------------------------------ From: FrankWood95 [at] aol.com Message-ID: Date: Fri, 29 Oct 2004 18:02:38 EDT Subject: Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look In a message dated 29/10/04 21:51:44 GMT Daylight Time, psyd [at] cox.net writes: > While I would also tend to lean that way, devil's advocate would have to > say that the word 'coincindent' came from somewhere. > Once implies possibility. Twice implies probability. Tthree times implies > proof. Thereby coining the phrase, "Third time's the charm". I learnt this differently. Once is happenstance; twice is co-incidence. The third time, it's enemy action! Frank Wood ------------------------------ Message-ID: <4182C1C1.7050206 [at] fuse.net> Date: Fri, 29 Oct 2004 18:18:41 -0400 From: Stuart Wheaton Subject: Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look References: In-Reply-To: CB wrote: > > Now, I'm just a novice welder, steel only, and MIG only at that, butI do > solder a great deal. I've welded quite a bit of aluminum, but again, confined to MIG only. In all probability, Truss would be TIGged, since that allows much more control over heat and filler added to the weld. > Questions: > 1. Does "cold weld" equate to "cold solder joint"? Pretty much, yes, I would call it an underpenetrated weld. In essence, the base metal did not melt sufficiently to allow a structurally adequate cross sectional area of sound metal to mix together between the two components of the welded joint. > 2. What does "penetration" mean in an aluminium weld? Same as in steel weld, how deeply does the base metal melt and fuse with the filler metal to form the weld. > 3. If cold welds were the problem, wouldn't the welds be peeling away from > the work, as opposed to the weld actually breaking as they appear to have > done , at least to my eye, in the photos? The trouble seems to be that the edges of the plate that show up in the photo seem not to have ever melted, thus perhaps the weld did not go as deep into the joint as it should have. If there was a thin section in the joint, because not enough metal melted, then that section would be weaker and more likely to fracture or tear through. > 4. Isn't aluminum welding more like hot gluing than steel welding? > (Remember, I'm somewhat ignorant of the process) NO!!!! Welding is welding, gluing is gluing... Sorry, pet peeve. Aluminum welding involves melting the base metal, hot gluing most materials does not alter the base material at all. More appropriately, Soldering is like hot gluing, the solder wets the wires, but does not penetrate the metal at all. I was hoping that Dale would pass things on to Ernie, he's a gifted welding instructor. Maybe Shawn Nolan could help here too. Stuart ------------------------------ Message-Id: <6.1.2.0.0.20041029152847.022fbe50 [at] localhost> Date: Fri, 29 Oct 2004 15:32:09 -0700 From: Jerry Durand Subject: Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look In-Reply-To: References:

At 03:18 PM 10/29/2004, you wrote: >Aluminum welding involves melting the base metal, hot gluing most >materials does not alter the base material at all. More appropriately, >Soldering is like hot gluing, the solder wets the wires, but does not >penetrate the metal at all. Actually, tin/lead solder dissolves copper* and will pretty much completely remove any gold or silver plating. This is normally considered a bad thing in electronics, and I doubt it helps strength any. *the amount of copper dissolved is small, but if you resolder a lot of times or use a copper tip, you'll see the erosion. ---------- Jerry Durand Durand Interstellar, Inc. 219 Oak Wood Way Los Gatos, California 95032-2523 USA tel: +1 408 356-3886 fax: +1 408 356-4659 web: www.interstellar.com ------------------------------ Date: Fri, 29 Oct 2004 18:40:38 -0400 Subject: Re: Bizarre Multiple Catastrophic Truss Failure From: Bill Sapsis Message-ID: In-Reply-To: on 10/29/04 1:55 PM, CB at psyd [at] cox.net wrote: >> For the enlightenment of us sound guys: Another way to state this is: >> A connection point must always be inside 2 pick points. Is this correct? > > And against my better judgement, following the saying that a little > knowledge is a dangerous thing, let me also learn more about this rigging > thing. If it is correct, whymust they be inside? It seems to me that ten > foot of truss hanging on the end of a connection (given and even weight > distribution) three feet from the pick point receives less stress that any > of the other connections that are farther from the pick point, but inside > the span. Nosy lil sound guys wanna know.. The place where two pieces of truss are connected, no matter what style of connection (hence the bolt plate, spigot, bubble gum comment) must be supported. It is not designed to be a folcrum point and that's what it would be if it was 'outside' the pick up point. Zat help? Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile We stand behind, and under, our work. ------------------------------ Message-Id: <6.1.2.0.0.20041029155847.00afee68 [at] localhost> Date: Fri, 29 Oct 2004 16:02:23 -0700 From: Jerry Durand Subject: Re: Bizarre Multiple Catastrophic Truss Failure In-Reply-To: References:

At 03:40 PM 10/29/2004, you wrote: >The place where two pieces of truss are connected, no matter what style of >connection (hence the bolt plate, spigot, bubble gum comment) must be >supported. It is not designed to be a folcrum point and that's what it >would be if it was 'outside' the pick up point. It seems if you have a junction inside of pickup points, it's STILL being a fulcrum point. The important difference seems to me to be that the TOP of the junction (two of three pipes) should be in compression. If it's cantilevered then the bottom single pipe would be in compression and could bend. Is that correct? ---------- Jerry Durand Durand Interstellar, Inc. 219 Oak Wood Way Los Gatos, California 95032-2523 USA tel: +1 408 356-3886 fax: +1 408 356-4659 web: www.interstellar.com ------------------------------ Message-ID: <4182CDDA.3090301 [at] fuse.net> Date: Fri, 29 Oct 2004 19:10:18 -0400 From: Stuart Wheaton Subject: Re: Bizarre Multiple Catastrophic Truss Failure / more pix, second look References: In-Reply-To: FrankWood95 [at] aol.com wrote: A bunch of stuff, about welding. I say, "Well said! Sir" Stuart ------------------------------ Subject: RE: Bizarre Multiple Catastrophic Truss Failure / more pix, second look Date: Fri, 29 Oct 2004 16:20:24 -0700 Message-ID: <407DF7D68DD30440B5CEB70ED234D1CF0316E251 [at] excuswa100.americas.unity> From: "Cyr, Dale" I have had multiple emails between ernie and myself. *very* interesting comments. that guy has an amazing knowledge of welds/welding. I will be making a "Preliminary Findings of Fact" and posting it here, probably next Tuesday. (gotta do an outta town gig, leaving in a few minutes) dale cyr Training Supervisor IATSE Local 93 Spokane Wa >I was hoping that Dale would pass things on to Ernie, he's a=20 >gifted welding instructor. Maybe Shawn Nolan could help=20 >here too. >Stuart ------------------------------ Message-Id: <200410292353.i9TNrl7j012458 [at] mail09.syd.optusnet.com.au> From: "Mike Marriott" Subject: RE: Fresnel Replacement Recommendations Date: Sat, 30 Oct 2004 09:23:55 +0930 In-Reply-To: >Subject: Fresnel Replacement Recommendations > >I'd like to find a replacement for my 1kw 8" >- Chris Best fresnels I have ever seen, http://www.prolite.com.au/ I am not on the payroll of this company. Kind Regards Mike Marriott ------------------------------ Date: Fri, 29 Oct 2004 19:08:47 -0500 Subject: Re: Fresnel Replacement Recommendations From: Greg Persinger Message-ID: In-Reply-To: >> Subject: Fresnel Replacement Recommendations >> >> I'd like to find a replacement for my 1kw 8" >> - Chris Chris, I have had excellent results with the Desisti line of Fresnels. I think they are very comparable to Arri in output but cost much less. They are built well also. If you need a quality fixture I would definitely give them a look. Greg Persinger Vivid Illumination Greg [at] Vividillumination.com ------------------------------ Message-ID: <41830584.9030308 [at] audiovisualdevices.com.au> Date: Sat, 30 Oct 2004 13:07:48 +1000 From: David Duffy Subject: Re: Fresnel Replacement Recommendations References: In-Reply-To: Mike Marriott wrote: >For info, archives & UNSUBSCRIBE, see >--------------------------------------------------- > > > >>Subject: Fresnel Replacement Recommendations >> >>I'd like to find a replacement for my 1kw 8" >>- Chris >> >> > >Best fresnels I have ever seen, > >http://www.prolite.com.au/ > >I am not on the payroll of this company. > > I have a dozen of the PR7-PC 650W PC spots and I love them. The variable angle is quick to adjust and gives quite a range too. David... ------------------------------ From: StevevETTrn [at] aol.com Message-ID: Date: Sat, 30 Oct 2004 01:16:21 EDT Subject: Re: cold water ground b_ricie writes: >Can someone explain cold water ground to me and how it >helps alleviate hum in sound? At LDI last week, Bill Whitlock, President of Jensen Transformers, gave an outstanding presentation on the issues surrounding grounding and audio noise. Bottom line, much of what people do (or voodoo) is either ineffective at best or hazardous (and illegal) at worst. Even brand new gear is often designed and manufactured with built-in problems. When gear is improperly designed or interconnected, a voltage differential in the signal wire and the equipment grounding conductor results in noise that is superimposed on the signal. Once introduced, the noise will never go away. Isolation (not ground lift!!!) is the best way to break the circle of ground loops. Earth ground (green wire) is a requirement for safety in all electrical branch circuits per the National Electric Code. In some buildings, with metal water pipes, the "cold water" pipe may provide a solid path to earth. However, it may or may not be properly bonded to the electrical service. It could just introduce an extra set of ground loops to track down. There are several excellent (and not overly technical) white papers and FAQs on the Jensen web site that will provide you with more details. www.jensentransformers.com. Steve Vanciel Orlando, FL ETCP Electrical Skills Certification Working Group member ------------------------------ Message-ID: Date: Fri, 29 Oct 2004 23:12:26 -0700 From: Mat Goebel Subject: The Bright Blue Mailbox Suicide Note Has anyone done this show? My friend is directing it as a BCEFA benefit. I've volunteered to help with all things technical and I'd like some design input. -- Mat Goebel Entertainment Technical Services Paramount's Great America Cell: 510.693.1448 ------------------------------ End of Stagecraft Digest #179 *****************************