Does anyone know if there is a ready-made option for extending the forks on the Eventer 25 (probably the same size forks as Genie). I just bought a new line array and the fly bar is 36" deep, yet the forks are only 18" deep. The shackle points on the fly bar are on the 4 corners, so I need a way to extend the forks out far enough to use spansets to attach the front two shackles. Any ideas without spending a fortune to have something custom made? Surely this is an issue that comes up with fairly often.
Extending the forks on Sumner Eventer 25's
- Thread starter Brandon Blakeney
- Start date
Silas Pradetto
Graduate Student
Re: Extending the forks on Sumner Eventer 25's
Check the load rating of the lift - it is specified at a certain load center. Based on your setup there, you're going to exceed the rated load center (If the forks are 18" long, the load center is less than that). You could try to fly the array with the lift on the side, which also allows you to get a lot more curve to the array. The side flying method always worked for me when I thought hauling around Super Towers was a good idea.
Check the load rating of the lift - it is specified at a certain load center. Based on your setup there, you're going to exceed the rated load center (If the forks are 18" long, the load center is less than that). You could try to fly the array with the lift on the side, which also allows you to get a lot more curve to the array. The side flying method always worked for me when I thought hauling around Super Towers was a good idea.
Re: Extending the forks on Sumner Eventer 25's
The Eventners lose capacity very fast as you move out away from the column - definitely make sure you're not going to end up overloading.
The Eventners lose capacity very fast as you move out away from the column - definitely make sure you're not going to end up overloading.
Your weight limits drop very drastically when you extend a cantilevered member, wind rating for outdoor use probably takes a good hit as well.
(Apparently I did pay attention in my applied engineering classes)
(Apparently I did pay attention in my applied engineering classes)
Re: Extending the forks on Sumner Eventer 25's
Okay, we'll first things first. In your picture, your bumper is backwards. The picture of the array being flown by someone else is oriented correctly. Oriented the way you have it will leave no room for any down angle.
secondly, using this bumper on a genie lift is gonna be a kludge. Even the picture supplied is a kludge. Wrapping 4 span sets around the corners of the bumper is NOT the way it's supposed to be done. You're supposed to go to the hang points provided with proper shackles. The way this was flown is gonna be very difficult to get level. It also can make for a very unbalanced load since you're hanging from 4 different points with very different loading. Put a good bit of down angle curve In there and you're gonna weight the points closer to the lift, which would be safer. Go for a straighter hang on the next gig and the whole thing might fall on its nose.
i cannot think of a single way to fly This flybar on This lift that I would recommend. The "four corner" fly points on the frame is very limiting. If you've got motors you could bridle the points with short steel and get two points out of those, but obviously with a genie lift you're gonna lose valuable trim height doing that. Frankly. I've never seen such an inherently limited design on a flybar before. Others may know of a way to do this that I don't, but if I showed up to a job and the sound company owner gave me this rig to fly on this genie lift, I'd be ground stacking. Or going home. Not trying to rain on your parade or be "that paranoid safety guy". Just my humble opinion....
Okay, we'll first things first. In your picture, your bumper is backwards. The picture of the array being flown by someone else is oriented correctly. Oriented the way you have it will leave no room for any down angle.
secondly, using this bumper on a genie lift is gonna be a kludge. Even the picture supplied is a kludge. Wrapping 4 span sets around the corners of the bumper is NOT the way it's supposed to be done. You're supposed to go to the hang points provided with proper shackles. The way this was flown is gonna be very difficult to get level. It also can make for a very unbalanced load since you're hanging from 4 different points with very different loading. Put a good bit of down angle curve In there and you're gonna weight the points closer to the lift, which would be safer. Go for a straighter hang on the next gig and the whole thing might fall on its nose.
i cannot think of a single way to fly This flybar on This lift that I would recommend. The "four corner" fly points on the frame is very limiting. If you've got motors you could bridle the points with short steel and get two points out of those, but obviously with a genie lift you're gonna lose valuable trim height doing that. Frankly. I've never seen such an inherently limited design on a flybar before. Others may know of a way to do this that I don't, but if I showed up to a job and the sound company owner gave me this rig to fly on this genie lift, I'd be ground stacking. Or going home. Not trying to rain on your parade or be "that paranoid safety guy". Just my humble opinion....
Re: Extending the forks on Sumner Eventer 25's
You may want to confirm with Sumner that the forks you have are the stock length and have not been shortened. There are fork extenders for the Eventer 16 but non that I am aware of for the 25. I cannot confirm the stock fork length of the 25. The stock Genie ST-25 for has a length of 26" with a max load rating at 18" or less from the end mast end of the fork and a minimum spec'ed load rating at 24" from the mast end.
It appears that you array frame only offers front and rear shackle points. You can make a bridle between the front and rear points on your frame. If you make the legs the correct lengths they will join above the center of gravity for the angle that you want your array to hang. This will vary based on the number of boxes and how you curve the array. Hopefully your array software can provide a center of gravity point for you in its rigging information. I would expect this to be somewhere around the 18" from the mast. You will want to confirm this. Your array will now hang lower from the forks but you will be applying the load within spec for the lift.
You may want to confirm with Sumner that the forks you have are the stock length and have not been shortened. There are fork extenders for the Eventer 16 but non that I am aware of for the 25. I cannot confirm the stock fork length of the 25. The stock Genie ST-25 for has a length of 26" with a max load rating at 18" or less from the end mast end of the fork and a minimum spec'ed load rating at 24" from the mast end.
It appears that you array frame only offers front and rear shackle points. You can make a bridle between the front and rear points on your frame. If you make the legs the correct lengths they will join above the center of gravity for the angle that you want your array to hang. This will vary based on the number of boxes and how you curve the array. Hopefully your array software can provide a center of gravity point for you in its rigging information. I would expect this to be somewhere around the 18" from the mast. You will want to confirm this. Your array will now hang lower from the forks but you will be applying the load within spec for the lift.
Re: Extending the forks on Sumner Eventer 25's
Okay, I've got a possible idea.
You could bridle the front and rear points of the frame using short steel and then create a center point on your forks using a piece of square tubing placed (and clamped) across the TOP of the forks to help compensate for the lost trim height. I wouldn't use span sets for the bridle as a short bridle like this will present a significant load. Also, (and this should go without saying) use ONLY rated steel and shackles for this...
I'm sure a more qualified rigger will chime in and point out why what I've suggested won't work.
Okay, I've got a possible idea.
You could bridle the front and rear points of the frame using short steel and then create a center point on your forks using a piece of square tubing placed (and clamped) across the TOP of the forks to help compensate for the lost trim height. I wouldn't use span sets for the bridle as a short bridle like this will present a significant load. Also, (and this should go without saying) use ONLY rated steel and shackles for this...
I'm sure a more qualified rigger will chime in and point out why what I've suggested won't work.
Re: Extending the forks on Sumner Eventer 25's
I tried the flybar both ways, and yes I'm aware that the picture probably is backwards. I have to figure out a way to fly them from the lifts, I have neither the money nor physical resources for an array tower or roof system. We sometimes have truss available to fly from, but they will easily be overweight by the time you add the truss+lights. In my opinion that fly bar is WAY too big!!! Look how small the actual speaker is...
I tried the flybar both ways, and yes I'm aware that the picture probably is backwards. I have to figure out a way to fly them from the lifts, I have neither the money nor physical resources for an array tower or roof system. We sometimes have truss available to fly from, but they will easily be overweight by the time you add the truss+lights. In my opinion that fly bar is WAY too big!!! Look how small the actual speaker is...
Re: Extending the forks on Sumner Eventer 25's
By the way, with 6 per side we are only at 462 pounds + flybar so there is some wiggle room.
By the way, with 6 per side we are only at 462 pounds + flybar so there is some wiggle room.
Re: Extending the forks on Sumner Eventer 25's
Ok, just got off the phone with Sumner. Apparently the stock length of the forks is 27" and mine are only 18", I bought these lifts used so someone must have modified them.......27" is much closer so I guess I could either order some new forks or have an attachment made for mine.
Ok, just got off the phone with Sumner. Apparently the stock length of the forks is 27" and mine are only 18", I bought these lifts used so someone must have modified them.......27" is much closer so I guess I could either order some new forks or have an attachment made for mine.
Re: Extending the forks on Sumner Eventer 25's
Before I would call sumner, I would call TVI and tell them to design a more sensible fly grid. Any sort of rigging with that short of a permanent install is going to be a kludge. I don't have any idea what they were thinking you could do with that.
Before I would call sumner, I would call TVI and tell them to design a more sensible fly grid. Any sort of rigging with that short of a permanent install is going to be a kludge. I don't have any idea what they were thinking you could do with that.
Re: Extending the forks on Sumner Eventer 25's
Order new forks. Absolutely resist the urge to have the village smithy bang out something.
Order new forks. Absolutely resist the urge to have the village smithy bang out something.
Re: Extending the forks on Sumner Eventer 25's
This. And given the fact that your lifts were modified, I'd have them inspected by a factory-trained technician as well. You DO NOT want rigging equipment that does not meet the specifications of the manufacturer.
This. And given the fact that your lifts were modified, I'd have them inspected by a factory-trained technician as well. You DO NOT want rigging equipment that does not meet the specifications of the manufacturer.
Rotate the lift 90deg (facing offstage if possible). When you hang longer, curved arrays (that fit within the weighting capacities of the lift at desired trim height)), the array doesn't hit the mast.
BRad
BRad
Last edited:
Re: Extending the forks on Sumner Eventer 25's
Brandon,
You've got no wiggle room with a load hang point beyond 13" along the fork length. See pp. 12 of the Sumner Eventer 25 manual here: http://www.sumner.com/sumner/images/file/upload/operation_manuals/Eventer20_25_OpManual2010.pdf
Further, there's no way anyone should recommend for you to bridle at this 13" point along the forks, because we have no information about the flybar rating in any direction except for the downward static load. The very substantial shear and/or torsional loads that would be applied to the flying frame by such a bridle have not been certified for by the array manufacturer.
No way anyone who took statics in college would ever put their stamp on this without a number of other load tests or FEA simulations. See my previous post here:
http://soundforums.net/varsity/2215-statics-you-need-take-class.html
With caution,
Brandon,
You've got no wiggle room with a load hang point beyond 13" along the fork length. See pp. 12 of the Sumner Eventer 25 manual here: http://www.sumner.com/sumner/images/file/upload/operation_manuals/Eventer20_25_OpManual2010.pdf
Further, there's no way anyone should recommend for you to bridle at this 13" point along the forks, because we have no information about the flybar rating in any direction except for the downward static load. The very substantial shear and/or torsional loads that would be applied to the flying frame by such a bridle have not been certified for by the array manufacturer.
No way anyone who took statics in college would ever put their stamp on this without a number of other load tests or FEA simulations. See my previous post here:
http://soundforums.net/varsity/2215-statics-you-need-take-class.html
With caution,
Last edited: