Return-Path: X-Scanned-By: RAE MPP/Clamd http://raeinternet.com/mpp X-Scanned-By: This message was scanned by MPP Lite Edition (www.messagepartners.com)! X-Real-To: stagecraftlist [at] theatrical.net Received: by prxy.net (CommuniGate Pro PIPE 4.2.10) with PIPE id 22775656; Wed, 01 Jun 2005 03:00:26 -0700 X-ListServer: CommuniGate Pro LIST 4.2.10 List-Unsubscribe: List-ID: Message-ID: From: "Stagecraft" Sender: "Stagecraft" To: "Stagecraft" Precedence: list Subject: Stagecraft Digest #414 Date: Wed, 01 Jun 2005 03:00:11 -0700 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Disposition: inline X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on prxy.net X-Spam-Level: X-Spam-Status: No, score=-5.6 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.0.3 X-TFF-CGPSA-Version: 1.4f2 X-prxy-Spam-Filter: Scanned For info, archives & UNSUBSCRIBE, see --------------------------------------------------- Stagecraft Digest, Issue #414 1. Re: re Dead Cat Soap by "Andy Leviss" 2. Re: Strand 2212 and 2216 by Brian Munroe 3. Kliegl K96 & Kliegpac 12s by "Muller, David" 4. Re: designer anniversaries for June by Jason Tollefson 5. Re: Kliegl K96 & Kliegpac 12s by "Michael S. Eddy" 6. DC circuit by Warren Stiles 7. Pipe grid material by James Feinberg 8. Re: Pipe grid material by Steve Larson 9. Re: Pipe grid material by Bill Sapsis 10. Re: Pipe grid material by "Tony Deeming" 11. Re: Pipe grid material by "Scheu Consulting Services" 12. Re: Pipe grid material by Mike Katz 13. Rosco Trim Clamp recall by Jeff Holt 14. Re: Pipe grid material by Bill Sapsis 15. Re: Pipe grid material by "Steven Haworth" 16. Re: Pipe grid material by James Feinberg 17. Re: Pipe grid material by Bill Sapsis 18. Re: Pipe grid material by James Feinberg 19. Re: Pipe grid material by Bill Sapsis 20. Re: Pipe grid material by Delbert Hall 21. Re: DC circuit by "Jim at TheatreWireless.com" 22. Re: Pipe grid material by "Scheu Consulting Services" 23. Re: Patch boxes by FrankWood95 [at] aol.com 24. Re: Patch boxes by FrankWood95 [at] aol.com 25. Re: Rosco Trim Clamp recall by Brian Munroe 26. designer anniversary oops by "RICHARD FINKELSTEIN" 27. Re: Pipe grid material by Mike Brubaker 28. Re: Pipe grid material by "Tony Deeming" 29. Re: DC circuit by Jerry Durand 30. Re: Pipe grid material by Stuart Wheaton 31. Star*Par Vs. Source 4 Par by Bruce Purdy 32. Re: Pipe grid material by "Occy" *** 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. ---------------------------------------------------------------------- From: "Andy Leviss" Subject: RE: re Dead Cat Soap Date: Mon, 30 May 2005 21:44:23 -0400 Organization: Duck's Echo Sound Message-ID: <000601c56582$547254e0$a19afea9 [at] AndyLeviss> In-Reply-To: > Hm, the small amount of resistance in the trace could be a=20 > problem if the interference were strong enough. Depending on=20 > the equipment, lifting the ground might not be a solution. No, it wouldn't fix this issue. This is the one and only time where wiring pin 1 to the shell of the connector on the end of the cable that goes to the offending gear can be a viable "Band-Aid" solution, provided that the shell of the input connector is connected to the chassis.=20 > I wonder why the manufacturers do not fix this - it is simple=20 > and inexpensive to do. Inexpensive in concept, but if you've invested lots of money to design gear, it's more expensive to change, or at least that's the excuse they'll give. That, or just plain ignorance of the fact that it's a problem. AES has a standard, AES-48, which addresses this. A PDF copy is free for AES members, $25 for non-members (hard copy is $25 for either) at: http://tinyurl.com/8garr The summary for it reads, "This standard specifies requirements for the termination, within audio equipment, of the shields of cables supporting interconnections with other equipment, taking into account measures commonly necessary for the preservation of EMC (electromagnetic compatibility) at both audio and radio frequencies. The shielding (or screening) of audio equipment, cables, and microphones can be critical for EMC. The improper connection of these shields can cause common-impedance coupling in equipment. From XL connector usage, where Pin 1 is standardised as the designated shield contact, this has been identified as the =93Pin 1 problem=94" For a pretty good summary of the issue and what to do about it, see: http://tinyurl.com/8slyu I know Jim Brown is also quite an expert on the subject, he may have info on it on his site, do a google search for his name and/or Audio Systems Group. --Andy http://onefromtheroad.com Tools, Toys, and Tales for the Theatrical Technician --=20 No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.322 / Virus Database: 267.2.0 - Release Date: 5/27/2005 =20 ------------------------------ Message-ID: Date: Mon, 30 May 2005 23:27:14 -0400 From: Brian Munroe Reply-To: Brian Munroe Subject: Re: Strand 2212 and 2216 In-Reply-To: References: On 5/30/05, FrankWood95 [at] aol.com wrote: > I'm not knocking modern educational techniques. (Strike that: I am!) But,= at > the age of 13, given a light source, a lens holder of some sort, and a ta= pe > measure, I could have done that.=20 "a lens holder of some sort": a jig that would hold lenses at different heights off the bench "a light source": and shine a light thru the lense "a tape measure": The height that resulted in a sharp focus point... Am I missing something here? What is the difference? Brian Munroe bpmunroe [at] gmail.com ------------------------------ Message-ID: <3FBB59451418D511B53E00B0D0AADEBD9830B6 [at] pa-es1.arts.ucla.edu> From: "Muller, David" Subject: Kliegl K96 & Kliegpac 12s Date: Tue, 31 May 2005 09:47:00 -0700 Folks, Does anyone still have K96 dimmers or better yet Kliegpac12's still in operation? The Kliegpac uses the control and power cards from the K96 design. I just sold our Kliegpac 12s to a studio in Texas. They were operating fine when removed from the theater several years ago. Apparently there is a battery on the card that holds a resident patch. However in the 12 years the dimmers were in operation originally with an Entertainer then a Colortran board and finally an Express / Expression, we never changed the batteries. We did loose power on a couple of occasions, and had to reset the dimmers from time to time, which includes killing the power monetarily, and in all that time the battery power was never a factor. The dimmers always responded to the board. Has anyone encountered their K96 systems not working, to find the battery was actually the problem? Do you have a source for the replacement battery? Tried to get replacement batteries before I shipped it to Texas, to confirm whether that was the problem or not, but didn't find any in time. Thanks. David Muller, Technical Director B100 Royce Hall Box 951529 Los Angeles, CA 90095-1529 310. 794.4048 dmuller [at] arts.ucla.edu ------------------------------ Message-ID: <20050531171829.582.qmail [at] web51005.mail.yahoo.com> Date: Tue, 31 May 2005 10:18:28 -0700 (PDT) From: Jason Tollefson Reply-To: jason [at] tollefsondesigns.com Subject: Re: designer anniversaries for June In-Reply-To: > > June 17 > > 96th anniversary of the birth of lighting designer, Abe Feder > > June 27 > > 96th Anniversary of the birth of lighting designer, Abe Feder > > > Anybody else note this...? hmmmm When was Abe Feder born? Perhaps we all need to say a little prayer for Abe's poor mother. Imagine, 10 days of labor... Jason Tollefson ------------------------------ Message-ID: Reply-To: From: "Michael S. Eddy" Cc: dmuller [at] arts.ucla.edu ('Muller, David') Subject: RE: Kliegl K96 & Kliegpac 12s Date: Tue, 31 May 2005 13:30:09 -0400 In-Reply-To: David Muller wrote, Does anyone still have K96 dimmers or better yet Kliegpac12's still in operation? The Kliegpac uses the control and power cards from the K96 design. Apparently there is a battery on the card that holds a resident patch. Has anyone encountered their K96 systems not working, to find the battery was actually the problem? Do you have a source for the replacement battery? Tried to get replacement batteries before I shipped it to Texas, to confirm whether that was the problem or not, but didn't find any in time. David, The batteries do conk out after so long a time, and yes the K-96 kept the patch on the card. For replacements and parts, I would highly recommend Horst Emmert who knows a lot about Kliegl dimmers and maintenance thereof as well as having a stock of replacement parts. Also, Steve Short of Lite-Trol may have Kliegl parts as well. Dimmer Performance Electronics, Inc. 326 Sherwood Drive Paramus, NJ 07652 201-262-7299 201-262-0444 Fax 800-631-5056 Contact: Horst Emmert Lite-Trol Service Company 485 West John Street Hicksville, NY 11801 516-681-5288 516-681-7288 Fax Email: LITETROL [at] aol.com WWW: http://www.litetrol.com Stephen Short I hope this helps, Michael Eddy Eddy Marketing & Consulting ------------------------------ Message-ID: <4590d63e05053111493b0e1fe [at] mail.gmail.com> Date: Tue, 31 May 2005 13:49:22 -0500 From: Warren Stiles Reply-To: Warren Stiles Subject: DC circuit I have a question for the electrical engineers among you. I need to build a slow rise DC switch. Reaching way back to my rusty high school electronics, my initial thought was to build a capacitor/resistor network to act as a variable voltage divider. My idea was that as the capacitor charged the reactance would increase and change the voltage in the other leg of the circuit. I believe that the effect would be the opposite of a soft mute. Anyway, this didn't work and I'm not tech savvy enough to know why. The Application: I have a prop consisting of several electric candles on a tray, wired in parallel and each with it's own on/off button. The entire unit is powered by a pair of 9Volt batteries in series. The lamps are buried in the body of the candles causing the entire piece to glow, so there is no need for a flicker or anything else to simulate actual flame. The problem is that as each candle is "lit" it pops on suddenly. I'd like to smooth out that pop into a 1 or 1.5 second fade up. Unfortunately the actor isn't dexterous enough to operate variable resistors and ramp each lamp up independently. Due to our budget, wireless dimming is not possible (sorry Jim). If anyone has suggestions as to how I should approach this, or where I could find more information on building DC circuits, I'd appreciate it. TIA. G. Warren Stiles ------------------------------ Date: Tue, 31 May 2005 12:00:33 -0700 Subject: Pipe grid material From: James Feinberg Message-Id: <43B87522-D206-11D9-9D42-00039367B7D4 [at] sandiego.edu> Wonder of wonders, our Theatre Arts program is about to get a new black box classroom theatre. The contractor took a look at the pipe grid we have in another space and said, "Oh, it's sprinkler pipe." He plans to install sprinkler pipe (which he says is Schedule 40) and "red head" it into the concrete ceiling. I don't have any reason not to trust him, but I'm looking for a second opinion that this will indeed work for us as a pipe grid from which to hang lights and scenery. Can anyone reassure me? many thanks, --James Feinberg University of San Diego ------------------------------ Date: Tue, 31 May 2005 15:08:40 -0400 Subject: Re: Pipe grid material From: Steve Larson Message-ID: In-Reply-To: I've never dealt with a fire marshal yet who would allow a sprinkler pipe to be used to hang lights or anything else from it. Steve > From: James Feinberg > Reply-To: "Stagecraft" > Date: Tue, 31 May 2005 12:00:33 -0700 > To: "Stagecraft" > Subject: Pipe grid material > > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > Wonder of wonders, our Theatre Arts program is about to get a new black > box classroom theatre. The contractor took a look at the pipe grid we > have in another space and said, "Oh, it's sprinkler pipe." He plans to > install sprinkler pipe (which he says is Schedule 40) and "red head" it > into the concrete ceiling. > > I don't have any reason not to trust him, but I'm looking for a second > opinion that this will indeed work for us as a pipe grid from which to > hang lights and scenery. Can anyone reassure me? > > many thanks, > --James Feinberg > University of San Diego > > > ------------------------------ Date: Tue, 31 May 2005 15:16:43 -0400 Subject: Re: Pipe grid material From: Bill Sapsis Message-ID: In-Reply-To: Beware. Ye have wandered into the land of darkness and confusion. Few who enter ever see the light of day again. The pipe you want is 1.5" ID (nom.) sch. 40 steel pipe. Accept no substitutes. Do not let the contractor join pipes (to make runs longer than 21') with threaded couplings. Unless, of course, you want the pipes to break at the joints. He should join them with internal sleeves. The contractor may be using the term "red heads" as a generic name for masonry anchors, but it's also the name of a specific style of anchor. I would not recommend that style for supporting a pipe grid, especially when the anchor is used in tension. I would suggest a chemical type (epoxy) anchor similar to what Hilti makes. (I would use Hilti if I were you but I don't want to get into a brand name argument) And what is he using for connecting two pipes that cross each other? Does he know that he should support the bottom pipes with the suspension device? How is he connecting the pipe grid to the anchor? Threaded rod, maybe, like they usually do? Another bad idea. And the list goes on and on. Yes, I know you trust your contractor. But the number of grids I have seen put in correctly by contractors I can count on one hand. The number of poorly installed grids, even by well meaning but inexperienced contractors, is too numerous to count. Be vewy, vewy, cawfull when hunting wabbits and installing pipe gwids. Zat help? Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile Please support the Long Reach Long Riders on their 2nd annual benefit ride http://sapsis-rigging.com/LRLR.html on 5/31/05 3:00 PM, James Feinberg at feinberg [at] sandiego.edu wrote: > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > Wonder of wonders, our Theatre Arts program is about to get a new black > box classroom theatre. The contractor took a look at the pipe grid we > have in another space and said, "Oh, it's sprinkler pipe." He plans to > install sprinkler pipe (which he says is Schedule 40) and "red head" it > into the concrete ceiling. > > I don't have any reason not to trust him, but I'm looking for a second > opinion that this will indeed work for us as a pipe grid from which to > hang lights and scenery. Can anyone reassure me? > > many thanks, > --James Feinberg > University of San Diego > ------------------------------ From: "Tony Deeming" Subject: RE: Pipe grid material Date: Tue, 31 May 2005 20:13:58 +0100 Message-ID: In-Reply-To: -----Original Message----- From: Stagecraft [mailto:stagecraft [at] theatrical.net]On Behalf Of James Feinberg Sent: 31 May 2005 20:01 To: Stagecraft Subject: Pipe grid material For info, archives & UNSUBSCRIBE, see --------------------------------------------------- Wonder of wonders, our Theatre Arts program is about to get a new black box classroom theatre. The contractor took a look at the pipe grid we have in another space and said, "Oh, it's sprinkler pipe." He plans to install sprinkler pipe (which he says is Schedule 40) and "red head" it into the concrete ceiling. I don't have any reason not to trust him, but I'm looking for a second opinion that this will indeed work for us as a pipe grid from which to hang lights and scenery. Can anyone reassure me? many thanks, --James Feinberg University of San Diego You're kidding, right? Not knowing exactly what sprinkler pipe is, diameter, wall thickness etc, doesn't make me an expert, but I'd seriously doubt that something designed for taking water around a building is going to be anywhere near strong enough to trust the suspension of heavy metal/timber objects! Ask him this question: Would he use sprinkler pipe to construct a work platform at the same height to take people? Then I'd look into the size of the pipe itself and ask yourself this one: Even IF it were strong enough, is it the right size to fit my C-clamps and hanging irons etc? THEN I'd suggest to the powers that be that they might want to get expert advice before hanging ANYTHING above students!! If this guy isn't a theatre contractor (which I really can't see him being) then his opinion's worth squat as far as I see. Ynot ------------------------------ Reply-To: From: "Scheu Consulting Services" Subject: RE: Pipe grid material Date: Tue, 31 May 2005 15:14:59 -0400 Organization: Scheu Consulting Services, Inc. Message-ID: In-reply-to: James Feinberg wrote: >I don't have any reason not to trust him, but I'm looking for a second=20 >opinion that this will indeed work for us as a pipe grid from which to=20 >hang lights and scenery. Can anyone reassure me? 1 1/2" schedule 40 pipe will work best. Each hanging point should be designed for 500 lb of load. Hanging points should be rigid (i.e. min = grade 30 threaded rod) and not be spaced any greater than 10'-0" in any = direction. The best way to accomplish this is to arrange the pipes in a 4' x 4' = grid. How your contractor attaches to the ceiling/roof may be left to him, but = a structural engineer should sign off on the design. Also remember to have the ends of the pipes (every other on or so) = attached to the wall(s) to stop the grid from swaying. Cross grid connectors can be found though you local rigging dealer. I've been told to avoid "Cheesebroughs" as they may not be load rated. Good luck. Peter Scheu Scheu Consulting Services, Inc. www.scheuconsulting.com ------------------------------ Message-Id: In-Reply-To: References: Date: Tue, 31 May 2005 15:20:13 -0400 From: Mike Katz Subject: Re: Pipe grid material Cc: feinberg [at] sandiego.edu (James Feinberg) James , Congratulations on the new space, I would be concerned about the specs for the grid weight capacity. The red heads fasteners will be in straight withdrawal. An engineer should figure the weight capacity per foot of pipe, specify distance between supports and how the grid is to be attached to the ceiling and to itself. (cross pipes). That will not cost much to do and the grid coming down and killing someone will cost much more. On the pipe, schedule 40 pipe usually will work fine unless there are long spans, also make sure that he uses 1 1/2" pipe since many connectors are not available in 1 1/4 size. Mike >snip >Wonder of wonders, our Theatre Arts program is about to get a new >black box classroom theatre. The contractor took a look at the >pipe grid we have in another space and said, "Oh, it's sprinkler >pipe." He plans to install sprinkler pipe (which he says is >Schedule 40) and "red head" it into the concrete ceiling. > >I don't have any reason not to trust him, but I'm looking for a >second opinion that this will indeed work for us as a pipe grid from >which to hang lights and scenery. Can anyone reassure me? Snip -- Mike Katz Technical Director MIT Theater Arts Rinaldi Tile Building 77 Mass Ave E33-101 Cambridge MA 02139 617.253.0824 mkatz [at] mit.edu "Lunacy Abounds" ------------------------------ In-Reply-To: Subject: Rosco Trim Clamp recall Message-ID: From: Jeff Holt Date: Tue, 31 May 2005 15:26:56 -0400 Frankly, I prefer the big rope clamp and sunday method for clewing lines and hanging bags, but for those who use these clewing devices, there's a recall. See here: http://www.rosco.com/us/news/RiggingHardware.asp Jeff Holt ------------------------------ Date: Tue, 31 May 2005 15:34:30 -0400 Subject: Re: Pipe grid material From: Bill Sapsis Message-ID: In-Reply-To: Hey Tony. How do you really feel about it? Don't hold back so much next time, OK? <> And judging by the fact that Peter, Michael and I responded to the original post within nano-seconds we either A) are sitting around salivating at the idea of respondeing to a rigging post or B) we have nothing better to do or C) All of the above. Please note. Just because I used a multiple choice response format do not assume that this question will appear on the Rigging Certification exam. <> About that pipe. 1.5' sch 40 is indeed water pipe. Sometimes it's used for natural gas. It's what just about every theatre in the USA uses. The idea of using sprinkler style pipe is not necessarily a bad one. Depends on what he really means by the term. The idea of using pipe that's already installed that's being used for the sprinkler system is indeed a very bad idea. Zat help? Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile Please support the Long Reach Long Riders on their 2nd annual benefit ride http://sapsis-rigging.com/LRLR.html on 5/31/05 3:13 PM, Tony Deeming at deeming.tony [at] btinternet.com wrote: > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > > > -----Original Message----- > From: Stagecraft [mailto:stagecraft [at] theatrical.net]On Behalf Of James > Feinberg > Sent: 31 May 2005 20:01 > To: Stagecraft > Subject: Pipe grid material > > > For info, archives & UNSUBSCRIBE, see > --------------------------------------------------- > > Wonder of wonders, our Theatre Arts program is about to get a new black > box classroom theatre. The contractor took a look at the pipe grid we > have in another space and said, "Oh, it's sprinkler pipe." He plans to > install sprinkler pipe (which he says is Schedule 40) and "red head" it > into the concrete ceiling. > > I don't have any reason not to trust him, but I'm looking for a second > opinion that this will indeed work for us as a pipe grid from which to > hang lights and scenery. Can anyone reassure me? > > many thanks, > --James Feinberg > University of San Diego > > > > You're kidding, right? > > Not knowing exactly what sprinkler pipe is, diameter, wall thickness etc, > doesn't make me an expert, but I'd seriously doubt that something designed > for taking water around a building is going to be anywhere near strong > enough to trust the suspension of heavy metal/timber objects! > > Ask him this question: > Would he use sprinkler pipe to construct a work platform at the same height > to take people? > > Then I'd look into the size of the pipe itself and ask yourself this one: > Even IF it were strong enough, is it the right size to fit my C-clamps and > hanging irons etc? > > THEN I'd suggest to the powers that be that they might want to get expert > advice before hanging ANYTHING above students!! > > If this guy isn't a theatre contractor (which I really can't see him being) > then his opinion's worth squat as far as I see. > > Ynot > > ------------------------------ Subject: RE: Pipe grid material Date: Tue, 31 May 2005 14:34:28 -0500 Message-ID: <5D5187063B6B8B46A99E8C0D36E0EB093078F9 [at] danube.river.idm.com> From: "Steven Haworth" WAY back (and before I knew as much as I do now), I helped install a = small pipe grid. We used some type of red anchors into a concrete = ceiling, but used them horizonally (the ceiling had beams of concrete). = Figured that made 'em a little strong, as the load was weighing more on = the horizontal bolt coming out of the anchor, and on the beam, rather = then trying to pull the anchor straight out. - Steven ------------------------------------------------- Steven Haworth (sjh [at] idm.com) QA Manager http://magpie.idm.com/sjh/ ------------------------------ Date: Tue, 31 May 2005 12:39:57 -0700 Subject: Re: Pipe grid material From: James Feinberg In-Reply-To: Message-Id: Thanks to all for your speedy and insightful replies! Because this is part of a larger building renovation, the work is being done by the University's general contractor, not theatre specialists. So I am trying to be very careful to ask the right questions and watch out for the right things. I believe they are planning to use epoxy with the anchors, but I will confirm. And ensure that sleeves are used at joints instead of couplers (which Jay Glerum taught me are called "thread protectors" in the pipe industry). But what's wrong with using threaded rod to connect the grid to the anchors? Assuming it is rated and has a sufficient Working Load Limit, that is. thanks again, --James Feinberg University of San Diego On Tuesday, May 31, 2005, at 12:16 PM, Bill Sapsis wrote: > > > And what is he using for connecting two pipes that cross each other? > Does he > know that he should support the bottom pipes with the suspension > device? > How is he connecting the pipe grid to the anchor? Threaded rod, > maybe, like > they usually do? Another bad idea. > > And the list goes on and on. > > Yes, I know you trust your contractor. But the number of grids I have > seen > put in correctly by contractors I can count on one hand. The number of > poorly installed grids, even by well meaning but inexperienced > contractors, > is too numerous to count. ------------------------------ Date: Tue, 31 May 2005 15:53:43 -0400 Subject: Re: Pipe grid material From: Bill Sapsis Message-ID: In-Reply-To: Threaded rod is brittle. It is designed for a totally static load. Your grid, even when attached to the walls, is not completely static. Under movement the rod has a tendency to break. It is also just about impossible to safety off the attachment devices of threaded rod to anchor and pipe. Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile Please support the Long Reach Long Riders on their 2nd annual benefit ride http://sapsis-rigging.com/LRLR.html on 5/31/05 3:39 PM, James Feinberg at feinberg [at] sandiego.edu wrote: > But what's wrong with using threaded rod to connect the grid to the > anchors? Assuming it is rated and has a sufficient Working Load Limit, > that is ------------------------------ Date: Tue, 31 May 2005 12:54:01 -0700 Subject: Re: Pipe grid material From: James Feinberg In-Reply-To: Message-Id: So, when I explain to the contractor why threaded rod is not a good choice (thanks, Bill!), what should I propose as an alternative? --James Feinberg University of San Diego On Tuesday, May 31, 2005, at 12:53 PM, Bill Sapsis wrote: > Threaded rod is brittle. It is designed for a totally static load. > Your > grid, even when attached to the walls, is not completely static. Under > movement the rod has a tendency to break. It is also just about > impossible > to safety off the attachment devices of threaded rod to anchor and > pipe. > > on 5/31/05 3:39 PM, James Feinberg at feinberg [at] sandiego.edu wrote: > >> But what's wrong with using threaded rod to connect the grid to the >> anchors? Assuming it is rated and has a sufficient Working Load >> Limit, >> that is > > ------------------------------ Date: Tue, 31 May 2005 16:16:43 -0400 Subject: Re: Pipe grid material From: Bill Sapsis Message-ID: In-Reply-To: 1/4" Galv. Aircraft Cable or 1/4" gr. 30 proof coil chain. Bill S. www.sapsis-rigging.com 800.727.7471 800.292.3851 fax 267.278.4561 mobile Please support the Long Reach Long Riders on their 2nd annual benefit ride http://sapsis-rigging.com/LRLR.html on 5/31/05 3:54 PM, James Feinberg at feinberg [at] sandiego.edu wrote: > So, when I explain to the contractor why threaded rod is not a good > choice (thanks, Bill!), what should I propose as an alternative? ------------------------------ Message-ID: Date: Tue, 31 May 2005 16:21:12 -0400 From: Delbert Hall Reply-To: Delbert Hall Subject: Re: Pipe grid material In-Reply-To: References: James, Several people have offered some very good advice on constructing a pipe grid, but let me add one more suggestion to the list: require that the pipe grid be anchored to the walls of the theatre, or other structural steelwork, so that it cannot swing in any direction. If you don't specifiy this you might end up with a grid that will hold a large vertical load, but not the horizontal load that you can get with temporary rigging. -Delbert Delbert Hall Phone: 423-773-4255 ------------------------------ From: "Jim at TheatreWireless.com" Cc: warren.stiles [at] gmail.com ('Warren Stiles') Subject: RE: DC circuit Date: Tue, 31 May 2005 16:39:02 -0400 In-Reply-To: Message-Id: <20050531203902.XRLM26102.tomts10-srv.bellnexxia.net [at] p3m866> > I have a question for the electrical engineers among you. I > need to build a slow rise DC switch. Reaching way back to my > rusty high school electronics, my initial thought was to > build a capacitor/resistor network to act as a variable > voltage divider. An RC network will definitely work. Think of it as a supply resistor, and a storage capacitor in parallel with a load resistor. Your candle lamp is the load resistor, and the values of the parts in the rest of your network must accommodate it. To create longer ramps you will need a larger capacitor and/or a larger supply resistor, but a larger resistor also introduces a greater voltage drop. Use an ammeter and Ohm's Law (resistance in Ohms = voltage in Volts / current in Amps) to determine the resistance of your lamps when lit -- if you measure them with an ohm meter you will see a dead short or a value that is much too low. Start with a supply resistor that is roughly 10% to 20% of the resistance of your load. Remember to use a high enough wattage to avoid overheating. This will give you a voltage drop that is probably noticeable but acceptable. Then put a large capacitor across the load to introduce the ramp. You'll need a fairly high value electrolytic. When you first apply power the supply resistor must charge the capacitor, creating the ramp. When you remove power, the lamp will fade as it discharges the capacitor. I'm writing this without mocking it up to make sure I haven't made any dumb mistakes, but I do this kind of thing all the time. If you continue to have trouble feel free to contact me on or off list. It's a very simple exercise. > Due to our budget, wireless dimming is not possible (sorry Jim). No sweat -- thanks for thinking of us! Jim www.theatrewireless.com ------------------------------ Reply-To: From: "Scheu Consulting Services" Subject: RE: Pipe grid material Date: Tue, 31 May 2005 17:06:41 -0400 Organization: Scheu Consulting Services, Inc. Message-ID: In-reply-to: Bill Sapsis wrote : >Threaded rod is brittle. It is designed for a totally static=20 >load. Your grid, even when attached to the walls, is not=20 >completely static. Under movement the rod has a tendency to=20 >break. It is also just about impossible to safety off the=20 >attachment devices of threaded rod to anchor and pipe. I think you're partially right in that "normal" threaded rod (Plain = steel AISI C1006 to C1022) would be problematic in this regard. I was mistaken earlier in saying Grade 30 should be used. No such animal exists. Oops. What should be used (or what I would use) is Grade B7 Alloy steel, which = has almost twice the tensile strength of plain steel. I just don't like using chain, because It's hard to get all the slack = out to get even loading on all the hangers, and I know how Unca Bill feels = about turnbuckles in load path. But you're wrong on one account. I do have PLENTY to do. Just this is = WAY more interesting than what I'm working on (and how sad is THAT!). Peter Scheu Scheu Consulting Services, Inc. www.scheuconsulting.com ------------------------------ From: FrankWood95 [at] aol.com Message-ID: Date: Tue, 31 May 2005 17:13:41 EDT Subject: Re: Patch boxes In a message dated 5/30/05 12:29:08 AM W. Europe Daylight Time, dale [at] cybercom.net writes: << Because in the modern world of audio and video, they have these things called multi-connectors. These allow you to connect up however many circuits all at once, with far less chance of getting channel 12 and 21 mixed up again. >> If they are correctly wired; if they are run in cables which are reasonably proof against external interference. If they are correctly labelled, and correctly earthed. Personally, I should rather spend a little more time in connecting up, rather than a lot of time in sorting out problems. Doing it right the first time is the best answer. Individual cables from XLR boxes on stage to the sound patch panel are known to work reliably. This is the way that the BBC used to wire TV studios. Old-fashioned, maybe, but it worked first time, and all of the time, wiring errors apart. That's the way I want an installation to be. ------------------------------ From: FrankWood95 [at] aol.com Message-ID: <15c.519174ca.2fce2d8d [at] aol.com> Date: Tue, 31 May 2005 17:13:49 EDT Subject: Re: Patch boxes In a message dated 5/30/05 3:45:16 AM W. Europe Daylight Time, gbierly [at] dejazzd.com writes: << NOTE my quote above. I apologize for the above generalization. I was specifically thinking of a touring engineer using a house multipin connector. It is just too risky the house is not wired the same as the touring gear. I have come across many engineers that would not touch a houseline period, but many have tied into a few here or there to simplify everyones day. Hope I didn't offend too many of you out there. (Sorry Andy and Chris) >> I fear that you are right.Who knows what happens inside a miltipin connector? ------------------------------ Message-ID: Date: Tue, 31 May 2005 17:51:50 -0400 From: Brian Munroe Reply-To: Brian Munroe Subject: Re: Rosco Trim Clamp recall In-Reply-To: References: From Rosco: "Failure of this component may lead to an unanticipated rapid descent of the load secured by the Easy Trim Clamp as well as the sandlbags counter-weighting the load" That's one way of saying "runaway" Brian Munroe bpmunroe [at] gmail.com ------------------------------ Message-ID: From: "RICHARD FINKELSTEIN" Subject: designer anniversary oops Date: Tue, 31 May 2005 17:59:49 -0400 Thanks for spotting this, Seth. >June 17 > 96th anniversary of the birth of lighting designer, Abe Feder >June 27 > 96th Anniversary of the birth of lighting designer, Abe Feder I guess this means that he was "born again" Indeed though if any of you have Bobbi Owen's excellent book of Broadway designer credits handy, I'd love a tie breaker on his REAL birthday. RichardF ------------------------------ Message-Id: <6.2.0.14.0.20050531170707.046e1800 [at] mail.insightbb.com> Date: Tue, 31 May 2005 17:08:49 -0500 From: Mike Brubaker Subject: Re: Pipe grid material In-Reply-To: References: Wagner (pipe fitting supplier) makes a line of weldable pipe fittings that can be used to make a very nice flat grid. They make a lot of useful items, actually. Mike At 02:14 PM 5/31/2005, you wrote: >Cross grid connectors can be found though you local rigging dealer. I've >been told to avoid "Cheesebroughs" as they may not be load rated. ------------------------------ From: "Tony Deeming" Subject: RE: Pipe grid material Date: Wed, 1 Jun 2005 00:10:06 +0100 Message-ID: In-Reply-To: >>Bill S said.... Hey Tony. How do you really feel about it? Don't hold back so much next time, OK? <> And judging by the fact that Peter, Michael and I responded to the original post within nano-seconds we either A) are sitting around salivating at the idea of respondeing to a rigging post or B) we have nothing better to do or C) All of the above. Please note. Just because I used a multiple choice response format do not assume that this question will appear on the Rigging Certification exam. <> About that pipe. 1.5' sch 40 is indeed water pipe. Sometimes it's used for natural gas. It's what just about every theatre in the USA uses. The idea of using sprinkler style pipe is not necessarily a bad one. Depends on what he really means by the term. The idea of using pipe that's already installed that's being used for the sprinkler system is indeed a very bad idea. Zat help? Bill S. Just calling as I saw it... 8-))) (Which may have been a little wide on a couple of points, so thanks for straightening me out on the pipe!) Just seemed a little un-safe to have what sounded like a non-theatre experienced contractor specifying something that must by definition be load rated. Ho hum! 8-))))))))) Ynot ------------------------------ Message-Id: <6.2.1.2.0.20050531172146.029857f0 [at] 192.168.0.13> Date: Tue, 31 May 2005 17:23:00 -0700 From: Jerry Durand Subject: Re: DC circuit In-Reply-To: References: At 01:39 PM 5/31/2005, you wrote: >An RC network will definitely work. Think of it as a supply resistor, and a >storage capacitor in parallel with a load resistor. Your candle lamp is the >load resistor, and the values of the parts in the rest of your network must >accommodate it. To create longer ramps you will need a larger capacitor >and/or a larger supply resistor, but a larger resistor also introduces a >greater voltage drop. Years ago I did this with a resistor, capacitor, power transistor, and a switch. The transistor lets you handle a LOT more power without having a huge capacitor (I think I had about 10W worth of lamp to dim). ---------- Jerry Durand Durand Interstellar, Inc. 219 Oak Wood Way Los Gatos, California 95032-2523 USA tel: +1 408 356-3886, USA toll free: 1 866 356-3886 web: www.interstellar.com ------------------------------ Message-ID: <429D2D27.6000501 [at] fuse.net> Date: Tue, 31 May 2005 23:36:07 -0400 From: Stuart Wheaton Subject: Re: Pipe grid material References: In-Reply-To: Scheu Consulting Services wrote: > Cross grid connectors can be found though you local rigging dealer. I've > been told to avoid "Cheesebroughs" as they may not be load rated. > Provided that, as Bill suggested, the grid is supported from the bottom pipe, the cheeseboros are only acting as position holding devices and thus do not have to be load rated, do they? I wouldn't use cheeseboros in the main grid frame in order to limit the later alterations of the basic grid, but for adding later, show specific pipes between bays, above the grid and crossing more than one pipe, I think they are very useful. Stuart ------------------------------ Date: Wed, 01 Jun 2005 01:24:21 -0400 Subject: Star*Par Vs. Source 4 Par From: Bruce Purdy Message-ID: I am looking towards a possible purchase down the road of some of these instruments. The Altman Star*Par, and the Source 4 Par seem on the surface to be almost identical, but looking at the Spec sheets there are various differences. For one thing, the S4 PAR EA is listed as weighing only 7.5 lbs, whilst the Altman unit claims to be 19 lbs. (Neither says whether the weight includes a lens or not, which I would expect makes quite a difference.) The Altman unit appears to be brighter, and has a narrower beam angle. Does anyone have actual experience with both? Do you prefer one over the other? Any advice?? Bruce -- Bruce Purdy Technical Director Smith Opera House ------------------------------ Message-ID: From: "Occy" References: Subject: Re: Pipe grid material Date: Wed, 1 Jun 2005 00:54:52 -0700 Ah, pipe grids properly designed are 6' to 10' apart spacing running up and down stage with right angle steel/iron Scaffolding clamps holding the cross stage pipes. Sway braces attached to the supporting structure not the walls at 25' feet min each way going up, down and across stage. The reason you never attach to the wall is expansion, compression and natural problems like earthquakes. As suspension use again the 6' to 10' rule unless the supporting structure is more than 7.5' above the grid and 1/2 all thread is used is fine with proper supporting clamps and sway braces for the pipe grid. I personally won't use any type of shot in or compression anchors in concrete unless they are in shear mode ( made many millions of yards concrete) thru bolt is the only way in concrete unless it was embedded in the concrete. ----- Original Message ----- From: "Stuart Wheaton" >> Provided that, as Bill suggested, the grid is supported from > the bottom pipe, the cheeseboros are only acting as position > holding devices and thus do not have to be load rated, do they? > > I wouldn't use cheeseboros in the main grid frame in order > to limit the later alterations of the basic grid, but for > adding later, show specific pipes between bays, above the > grid and crossing more than one pipe, I think they are very > useful. > > Stuart > > > ------------------------------ End of Stagecraft Digest #414 *****************************