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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Frank Koenig on May 26, 2018, 06:35:00 pm

Title: Bungee Cords for Springy Hoist Ropes
Post by: Frank Koenig on May 26, 2018, 06:35:00 pm
In my ceaseless quest to simplify the erection (and striking) of the Trabes 4.5m towers I've come up with one more little hack. When putting up the tower it's necessary to thread the wire rope across two pullies on the cross arm while the tower is lying on its side. I then walk the tower up with arms outstretched overhead while pivoting it on one of the two base legs. This is fine except that the (somewhat springy) rope wants to jump out of the pullies and, in any case, ends up out of reach once the tower is up.

Last time I did this I hooked two (~2.5 ft. relaxed) bungee cords in series with one end hooked onto the eye on the end of the rope and the other hooked low down on the truss. This keeps the rope taught, in its grooves, and, so long as the lower bungee in within reach from the ground, accessible. The bungees supply sufficient tension to aid in the formation of an orderly initial wind on the winch, too.

My other trick, which I mentioned once before, is not to wind in the rope when putting away the towers. I coil it and secure it with a Velcro tie, just like a mic cord. This saves a lot of time and cranking. For what it's worth.

--Frank

(http://TrabesBungee.jpg)   
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Jeff Lelko on June 12, 2018, 04:14:56 pm
Hi Frank, seeing as you haven't gotten any other replies here do you mind if I ask in general how you like these specific lifts?  Which speakers do you use them with, and what led you to choose these over something like the Applied Mini Line Array Lifts or Sumner Eventers? 

Thanks!
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Stephen Kirby on June 12, 2018, 04:58:58 pm
Sounds like he can put them up as a one man operation.  Something I've never wanted to get involved with by using real line array lifts like Genies.
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Geert Friedhof on June 12, 2018, 05:19:46 pm
Sounds like he can put them up as a one man operation.  Something I've never wanted to get involved with by using real line array lifts like Genies.

+10  ;D

Just buy 2 2000 dollar lifts, and be done with it.
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Frank Koenig on June 13, 2018, 10:56:06 am
Hi Frank, seeing as you haven't gotten any other replies here do you mind if I ask in general how you like these specific lifts?  Which speakers do you use them with, and what led you to choose these over something like the Applied Mini Line Array Lifts or Sumner Eventers? 

Thanks!

Hi Jeff, I like them well enough. I also think there is still room for innovation in speaker support on that scale. They are rated at 600 lbs and I am now using them to fly SH96s, which are ~220 lbs. Frankly, I wouldn't want to put anything much heavier on them. I've been asked by a local production company if I want to rent them out but declined because I'm afraid they'll get messed up.

Pluses:
Light weight and reasonably compact. I believe they are a good bit lighter then Genie-style lifts. All the parts except 2 sections of vertical truss (~10 ft total) fit into a modest size road case that is easy for two people to lift.

Attractive appearance. I think they look nice -- much nicer than a Genie lift. No need to cover them up. They're Italian, after all  8)

One person erection. It's nice to have a helper but I can put them up and take them down all by myself if necessary.

Snatches the speaker from the ground -- no manual lifting. This they have in common with Genie lifts but is in opposition to the large crank stands that are primarily intended for lifting horizontal truss sections.

Towers are independent allowing any speaker spacing, unlike flying speakers from a long "proscenium" truss that limits the spacing.

Good stability and the option of adding ballast. Two adjustable feet allow for some amount of unlevel ground, such as road crown when setting up in a street.

Published engineering data.

Minuses:

Requires a clear area to lay the assembled tower on its side during erection.

Somewhat fiddly to assemble with lots of small parts (pins, etc.) to lose. Inexperienced helpers are baffled by them. Need to be carefully inspected to ensure proper assembly. One misplaced pin could cause catastrophic failure.

Somewhat delicate. Lightweight aluminum truss is easily dented.

Takes longer to erect and strike than a Genie lift (I presume, I've never used a Genie). Lots of cranking on the hand winch.

That's what comes to mind right now. I'm open to alternatives for getting speakers in the air, and tricks to make it easier.

--Frank
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Bob Faulkner on June 13, 2018, 02:16:54 pm
We use the Penn-Elcom lifts.

http://www.penn-elcom.com/default.asp?PN=SAS

Rather lightweight (~100 lbs) can support 600 lbs.  Ours have a max height of 14'.  Crank up/down.  Putting it together doesn't take too long, and can be done all with one person.  Takes up minimal trailer/van space - they do fit in the back of my cargo van (they've been in the trailer, but I prefer putting stuff in the trailer that packs well).
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Frank Koenig on June 13, 2018, 03:21:55 pm
We use the Penn-Elcom lifts.

http://www.penn-elcom.com/default.asp?PN=SAS

Rather lightweight (~100 lbs) can support 600 lbs.  Ours have a max height of 14'.  Crank up/down.  Putting it together doesn't take too long, and can be done all with one person.  Takes up minimal trailer/van space - they do fit in the back of my cargo van (they've been in the trailer, but I prefer putting stuff in the trailer that packs well).

I looked at the Penn-Elcoms when I became aware of them, which was after I got the Trabes. They're similar to what I was considering fabricating myself at one point. (Just as well I didn't do that.)

I see two issues. The 36 in. width only works for narrow speakers. The SH96 is a whopping 45 in. wide so won't fit unless you turn the stand sideways and have one of the vertical supports in front of the speaker. The lower transverse member looks like it prevents you from putting the speaker directly under the hoist point, so a little lifting or guiding is necessary. That probably is OK for a single small speaker but could be a pain with a big dog such as the SH96 or a small array. Even with the Trabes it takes a bit of maneuvering to  get the SH96 in position for hoisting and you have to guide it on the way to keep it from rotating and banging into the vertical truss. I have the speaker cable attached at the speaker end with a Kellems grip and use it as a tether to guide the speaker.

Maybe what we need is an integrated speaker and stand. Picture a wheeled platform on which the speaker permanently resides. Some number of telescoping columns raise the speaker once the platform is in position, and a remote-controlled tilter lets you set the vertical angle. Folding outriggers keep it from tipping. While I'm dreaming, how about an electronic horizontal coverage control? 

--Frank
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Jeff Lelko on June 13, 2018, 04:19:50 pm
Thanks for the input Frank!  I do agree that aesthetically they are good looking stands and are still manageable by a single person if need be.  Stephen, is that something that you frown upon, and if so, why?  I'd think that limiting the number of multiperson jobs on site would help increase efficiency and decrease labor!  Aren't Genies/Eventers a one-person job too?  I do agree that they're heavy though.  I recall Mike Pyle liking the Cosmic Truss CT-5 option as a lighter weight stand, though I know Genies and Eventers are pretty much the industry standard.

I've seen the Penn-Elcom guillotine lifts and agree with Frank's concern, not to mention that I don't personally care for the look.  I think there's definitely room for innovation in this area of the market though.  I really like the type of lifts I've seen Peter Morris share pictures of for his small line array system (that use the subs as support/ballast) - very simple and compact.  I'm not looking to buy anything now - just filing away options that might be a good fit for a smaller operator when the time finally comes to upgrade my rig!  Thanks again!   
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Stephen Kirby on June 13, 2018, 05:23:54 pm
As primarily a one person operation, I want to stay small so I can handle it.  Have had problems finding folks that really help when I've stretched a bit.  So DSR's on DuraTruss crank stands is about as big as I want to go.  Maybe SM80s, but not anything larger.  Hauling a 200lb stand out of a truck and setting it up is too much work.
Long time forum folks may remember some stands that I built some 10 years ago for some DIY small "line array" type things.  These weighed about 70lbs each and set up pretty quick.  Only went about 12' high but worked for small street fairs and ballrooms.  There were several comments back then that the industry needed something like this.  Even though they were overbuilt I eventually tossed them due to liability concerns.
I've seen comments here in the past that the Penn-Elcom stands aren't for use outdoors.  They do look like they could sway a bit with any load that has significant windage.
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Jeremy Young on June 13, 2018, 06:01:59 pm
Reading along here as well.  I have no plans to add people to my one-man crew. An SM80 on an ST-132 works for what I'm doing, and another pair as delays or fills is probably where I'd go next if I need to expand. 

However, I am trying to keep my eyes on conversations like this so if I'm presented with an opportunity for larger gigs I understand the cost to get into the game. 

I could see the Penn-Elcom style working for something like an SM80F (because of its narrow width) but I agree with Frank that it wouldn't work for wider cabinets like the SH96 or a few horizontally splayed trapezoid cabinets like SH46's (sticking to the Danley vernacular this thread has had thus far). 

I've scoured the internet looking for solutions that don't involve truss across the front of the stage.  Love the utilitarian functionality, but hate the way it would affect the aesthetic in many of the odd-shaped rooms I find myself in.  Also all that truss adds considerable time to load-in. 

The Work Pro WT-150 seems to be about the only product that stands under 6' tall when folded in this category, which I'd prefer so it could stand up in my van as opposed to laying down which is not space efficient.  Anything over a Sumner Eventer 16 seems too heavy to be manageable by one person on anything other than flat smooth concrete. 

Frank do you have any photos of your Trabes tower disassembled?  Are they the lifts from this (https://soundforums.net/community/threads/4-july-hi-fi.7957/) thread? 
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Frank Koenig on June 13, 2018, 06:49:59 pm
Frank do you have any photos of your Trabes tower disassembled?  Are they the lifts from this (https://soundforums.net/community/threads/4-july-hi-fi.7957/) thread?

Yes, those are the ones. I don't have a picture of them disassembled and I can't take one right now because the stands are up in the Sierra Foothills and I'm down here in Palo Alto. I intend to bring them back down in the next week or two after I use one (up there) to get some pseudo-anechoic measurements on a new speaker project. Here's one in use doing measurement.

--Frank

(http://SH96towerMeas.jpg)

Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Jeff Lelko on June 14, 2018, 06:54:27 pm
As primarily a one person operation, I want to stay small so I can handle it...

Thanks Stephen, that all makes sense.  I'm much the same in that I want to stay as small and efficient as possible.  Of course there's only so big you can go before the logistics of the rig mandate a larger crew...and that's the sweet spot I'm trying to find for my system upgrade.

Yes, those are the ones. I don't have a picture of them disassembled and I can't take one right now because the stands are up in the Sierra Foothills and I'm down here in Palo Alto. I intend to bring them back down in the next week or two after I use one (up there) to get some pseudo-anechoic measurements on a new speaker project. Here's one in use doing measurement.

That's quite impressive.  Thanks for sharing!  Do you ever find the SH96s to be a bit much to handle alone?  One of the things I enjoyed most about the Danley Demo in Florida a few weeks ago was being allowed to move a few of the speakers too.  TH118s - no problem.  SM80F - doable but awkward at 215 pounds in a tilt-back design - especially when you hit a bump.  The 185 pound TH118XLs don't scare me, but anything heavier I think I'd want on a material cart or caster board.  How do you handle your SH96s?
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Frank Koenig on June 15, 2018, 01:34:21 am
Do you ever find the SH96s to be a bit much to handle alone?  One of the things I enjoyed most about the Danley Demo in Florida a few weeks ago was being allowed to move a few of the speakers too.  TH118s - no problem.  SM80F - doable but awkward at 215 pounds in a tilt-back design - especially when you hit a bump.  The 185 pound TH118XLs don't scare me, but anything heavier I think I'd want on a material cart or caster board.  How do you handle your SH96s?

Hi Jeff, I after all found a (not so good) picture of the packed-up Trabes. This is everything for one tower except the ~10 ft long vertical truss, which is in two (different sized) pieces, which, incidentally, can be used individually to make a shorter tower. There are two folded leg assemblies that include the telescoped angle struts, the vertical base section that has the winch attached to it, and the boom with the pullies that goes on top. The black, arrow-shaped object on top of the other stuff is not part of the tower.

As for handling SH96s, yes, they're right at the limit of what I can do. They have the corner wheels, just like the TH118s, but are heavier and shallower, which actually makes them harder to balance. As a long-time hand trucker I'm OK on level ground but ramping them in or out of the van is a real strain without a pusher to help. The hardest part is flipping them from rolling position to operating position within the confines of the legs of the tower. I'm still refining my technique :) And, as with the TH118s, helpers need to be informed not to lose control and slam them down at the end of the trip.

--Frank

(http://TrabesPacked.jpg)
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Geert Friedhof on June 15, 2018, 07:29:26 am
There are some 6 feet array lifts.

VMB, Kuzar come to mind.
Title: Re: Bungee Cords for Springy Hoist Ropes
Post by: Michael Lascuola on June 15, 2018, 08:02:34 am
...
Last time I did this I hooked two (~2.5 ft. relaxed) bungee cords in series with one end hooked onto the eye on the end of the rope and the other hooked low down on the truss. This keeps the rope taught, in its grooves, and, so long as the lower bungee in within reach from the ground, accessible. The bungees supply sufficient tension to aid in the formation of an orderly initial wind on the winch, too.

My other trick, which I mentioned once before, is not to wind in the rope when putting away the towers. I coil it and secure it with a Velcro tie, just like a mic cord. This saves a lot of time and cranking. For what it's worth.

--Frank



I, too am in a "ceaseless quest to simplify erection" :)

I'd love to see a video of the setup of this rig!