D-ring or Keeper plate?

Not exactly sure what you are asking, but a D-ring is intended to be used WITH a keeper plate. D-rings allow for a place to connect the terminated end of aircraft cable to a scenic unit with a shackle.

A keeper plate, sans D-ring, is typically used when bottom hanging a flat. Using the hardware in the the link you provided, one would attach a bottom hanging iron to the back side, bottom end of the stiles of a Broadway style flat. (Note that the bottom hanging iron is bend in such a way that it will only accept a Broadway style flat) Then, one would use keeper plates at the top of the stile, to keep the aircraft cable with the flat so that it will hang straight.

On a Hollywood flat, I prefer to put a keeper plate with D ring (or shackle plate, a wonderful improvement) at the inside bottom of the stiles. Then I route the the aircraft cable up the inside center of the stiles, drilling holes through the toggles and ultimately the top rail as I go up. I have found this to be the most effective way to get flats to hang plumb, as you aren't fighting the flats center of gravity, and it also centers the flat parallel to the batten, which can help with the normally tight clearances of fly systems.

Anyway, while bottom hanging a flat is preferable because it puts the flat into compression while hung, most people top hang because it can be hard to get a flat to hang plumb with bottom hanging, unless the method I described is used.

All of this, of course, is IMHO, YMMV. I expect others to chime in soon.


Other useful threads:
http://www.controlbooth.com/forums/scenery-props-rigging/17919-rigging-hardware-lowes.html
http://www.controlbooth.com/forums/scenery-props-rigging/27538-question-about-hanging-things.html
 
Last edited:
Yes, I see that I did not provide complete information. I am hanging Broadway style flats. My plan is to install shackle plates near the bottom on the back of the flat. I think I prefer these because the overall cost will be lower than the standard bottom hanging irons. I was thinking of using the keeper plates in the link installed at the top of the stiles so the aircraft cable can travel through it.

Alternately, if I understand all my research, instead of the keeper plate I could use a d-ring plate at the top either without the ring or with the ring. My question is this. If I use a D-ring plate with a d-ring then would my pre-made aircraft cable thimbles fit through the d-ring allowing me to remove the aircraft cable for storage between shows? I am thinking of not fiddling with bolts in between shows. Are there any other advantages or disadvantages to a d-ring vs these keeper plates?

And to add one more question... how much hardware do you guys keep on the flats between shows? How do you keep the flats from getting damaged in the truck from the attached hardware?
 
Last edited:
I have never known anyone to use a D ring as a top keeper when using bottom hanger irons, and I don't know of a way to use a D ring without a keeper plate, it is intended to be used with one. Even if the thimble does fit through a D ring, I don't think the flat will hang straight, as the flats center of gravity will cause the cable to pull the D ring at an angle away from the top of the flat, and thus the flat will hang on an angle.

Other's may argue, but a D-ring plate IS a keeper plate. The BMI Supply link just calls the older style a D-ring plate, and the newer, rated styles keeper plates.

Hardware left on depends upon how often said flats are used. If said flat is going to be reused repeatedly, or is part of a touring package, I'd keep the hardware on the flat. If said flat is going into storage, and it is unknown when it will be used again, I'd be more inclined to remove the hardware for use elsewhere.

I haven't touched a Broadway style flat since high school, but we just accepted that damage was part of soft cover flats, and we were always prepared to dutchmen and repair flats upon installation. Aside from building some sort of specialized flat transfer rack (which I have seen done, think cafeteria lunch tray cart), I think stacking flats alternating back - front front - back would be safest.
 
Last edited:
If you connect your flat to the rigging at the bottom of the flat (using whatever required and rated hardware that you need - including a turnbuckle for adjustment), then you will not want a large hole to feed the rope/GAC through as this will cause the flat to kick the bottom edge backwards. You preferably want something of equal diameter as your rope/GAC to feed through. You will not be able to feed your thimble through it for storage, but it will keep you plumb.
 
Yes, use the D-ring WITH the keeper plate... I always assume whenever you install a d-ring you have to use a keeper plate, I don't know why we are debating it here (unless it is welded on).

Like so...
proxy.php


Now there is a way to use the d-ring on top AND have the flat hang correctly. You use your pre-built rigging packages, shackle off to the bottom of the flat, come through the top of the D-ring, out the bottom, and then up to the next d-ring. It basically forces the GAC to hold the d-ring flush to the piece. You have to watch as your picking the piece to ensure none of the d-rings jam up, but it does work.
 
As for "How much hardware to leave on...?" If you are using the hardware correctly removal for storage is going to be a pain. You are through-bolting with 2, 1/4-20 bolts, then cutting the bolt flush after sucking the nut into the face of the flat right ? and only using #10 wood screws in the other two holes, right ?
 
Rigging order

For our next production I need to fly several sets. Five of them are studio flat construction; the heaviest grouping is 250lbs. The others are hybrid flat/soft drops??? that you can read more about in this other thread: http://www.controlbooth.com/forums/...31391-vinyl-printed-drop-scenery-netting.html If you check it out skip down to the bottom as we have tossed the netting idea out the window.

Pick points will be about 4 feet apart. Hardware will be bolted to the scenery. Flats will be attached to each other with loose pin hinges??

I want to do this safely and have tried to be very thorough in my research. I have read Glerum's Stage Rigging Handbook, scoured this forum, read several JRClancy white papers, and asked many questions. I know this research does not make me a rigger and want to make sure that I don't kill anyone. We will have experienced help flying our sets from the staff at the college auditorium we are renting. Could you look at my order and tell me if I seem to be on the right track?

Here is the order I am putting together at BMI Supply:

10123119 1/4" Long Link PC Chain ZP 133' Pail
111SPF014 Forged Screw Pin Shackle 1/4"
111THS018 Thimble 1/8" Standard 100/Pk
111NSC018 1/8" Copper Nico Sleeves 10/Pk
09132302 1/8"x500' 7x19 Black Powder Coat GAC
04DR003 Keeper Plate "Stubby"
04SP005 Shackle Plate - 90° Stubby #2030
111TJF386 Forged Turnbuckle 3/8"x6" Jaw/Jaw
12001SC Swager 1/16"-3/16" #1-SC

Here is my 'professional' illustration of what I plan to do:

2013-03-08 22.12.06.jpg

Should an answer to this question be more appropriate as a private message that is fine with me.
 
Re: Rigging order

Use wood screws or thru bolts to attach your hardware (not drywall screws) and I think you have that one licked.

There is a piece of hardware called a "bottom iron", may have other names too [bottom hanger iron, hooked hanger iron], that hooks under the flat. It is prefered as the weight doesn't rest on the fasteners.
.
 
Last edited by a moderator:
Re: Rigging order

I would forget the chain and just use a short 10" sling over the pipe basket style with a 1/4" shackle to your long sling
You will need to thru-bolt the hardware to the flat. On the bottom rail I prefer a bottom hanging iron, letting it do the work of lifting then the thru-bolt only has to keep it in place.
don't forget to mouse the turnbuckles
Grouped broadway flats i will tight pin hinge on the face. flip over, then add full width stiffeners 1x4 on edge with tight pin hinges alternating top and bottom on the stiles. if you are constructing in a remote shop you may want to use loose pin hinges so you can take the flats apart to transport them.
did you say these were Hollywood style flats? If so you may need to add a bottom rail of some sort to bolt the lifting hardware to.
you do need to figure just how long your slings need to be. a section drawing would help with that.
 
Re: Rigging order

If you have to hang things a lot and have the budget I would buy gliders [Verlock, Gripple]s instead of turnbuckles. They're fast to level something out with, and you have tons of adjustability since you can make the cable 3" long or 20' long in a few seconds.
 
Last edited by a moderator:
Re: Rigging order

did you say these were Hollywood style flats? If so you may need to add a bottom rail of some sort to bolt the lifting hardware to.

The names of these flats is so confusing when differant people you talk to call them different things. Mine are broadway style flats (1x laying on it's face) covered with luan. They are about 1 1\4 inches thick. Sorry if I confused anyone.
 
Last edited:
Re: Rigging order

If you have to hang things a lot and have the budget I would buy gliders [Verlock, Gripple]s instead of turnbuckles. They're fast to level something out with, and you have tons of adjustability since you can make the cable 3" long or 20' long in a few seconds.

I don't think I have that kind of budget but those sure look nice!! Is there a cheaper source for these?
 
Re: Rigging order

I like verlocks, but I usually see them used with a crosby clamp as a safety. I've seen ver-locks fail, and it's not the nicest thing. Useful for quick rigging or rigging where you're not entirely sure what height you'll need, but for something like this making picks of the same length is going to be quicker and safer.

Also, you might already own them, but I didn't see wire rope cutters (c7's or c9's) on your shopping list, make sure you have a pair.
 
At the link in post#1, the only difference between a Keeper Plate and a D-Ring Plate appears to be that the Keeper has rounded corners as opposed to the square corners of the D-ring plate.
8934-d-ring-keeper-plate-keeper_d-ring.jpg


Post#6 shows a D-ring plate WITH rounded corners.

In the late 1970s, I was taught, when flying a flat, Broadway to use a bottom hanger iron on the bottom, and then a D-ring plate without D-ring (I don't think Keeper Plate has been invented yet) captured the 1/8" GAC at the top. This method adds some construction complexity, but not all that much since a thimbled eye won't fit thru a D-ring anyway.

Unless I'm missing something, a Keeper Plate IS a D-Ring Plate, only without the D-ring. (EDIT: WHat Greenia said in post#4.) Why stock two parts? Just because one is 3.6% ($0.09) less cost?

... You are through-bolting with 2, 1/4-20 bolts, then cutting the bolt flush after sucking the nut into the face of the flat right ? ...
I've never done that. I was taught to use a 1" to 1.25" flathead (slotted) bolt thru the face of the 1x-and-canvas-flat with a washer and a hex nut on the back of the iron.

... Now there is a way to use the d-ring on top AND have the flat hang correctly. You use your pre-built rigging packages, shackle off to the bottom of the flat, come through the top of the D-ring, out the bottom, and then up to the next d-ring. It basically forces the GAC to hold the d-ring flush to the piece. You have to watch as your picking the piece to ensure none of the d-rings jam up, but it does work.
1. How do you get the thimble through the D-ring?
2. Does wrapping the D-ring not exceed the minimum stated bend radius of the wire rope?


A relevant edict: Always suspend joints under compression, not tension.

Mod note: Threads titled "D-ring or Keeper plate?" and "Rigging Order" have been merged together into this one.
.
 

Attachments

  • Keeper_D-ring.jpg
    Keeper_D-ring.jpg
    31.5 KB · Views: 649
Last edited:
Re: Rigging order

I don't think I have that kind of budget but those sure look nice!! Is there a cheaper source for these?
I've not compared prices, but I would suspect a Verlock or similar product from Griplock (the actual manufacturer of Ver Sales' Verlock) or others, would be price-comparable to a turnbuckle, shackle, and installed eye with thimble.

Random Google search reveals 1/8" Verlock Sr. Ring Gripper $32; 1/8" Griplock Ring Gripper $16.95. See also the old thread http://www.controlbooth.com/forums/...7-where-do-you-buy-your-rigging-supplies.html .


NOTE: ControlBooth and its members are offering construction and material suggestions only, based on experience and/or standard industry practice, and are NOT qualified to, or capable of, specifying solutions to specific rigging issues. All construction, materials, and practices must meet or exceed the most stringent of federal, state, and local applicable structural, building, electrical, fire, and life-safety codes.


When in doubt, ALWAYS consult a qualified professional, in person.​
.
 
Last edited:

Users who are viewing this thread

Back