Turntable Assembly and Installation
The following details will guide you through assembling the turntable. Along with these directions, you can check out this slideshow of the assembly process.
Installation Options
You can attach the turntable spider and the Revolver to your floor or deck with lag screws, bolts, masonry anchors, or your preferred fasteners. You can add fastener holes anywhere you like on the turntable spider. Keep in mind that the Revolver generates up to 1200 lbf of lateral thrust when its drive wheel is tensioned into the edge of the turntable, so your connections should be capable of withstanding that force. For this reason, drywall screws are not recommended as your sole floor fasteners.
If you are not able to attach the turntable to the floor, then you will need to find a method to resolve the horizontal force of the Revolver pressing into the side of the turntable. This could be an additional layer of plywood that goes underneath the Revolver and the turntable spider, or some other connection method of your choosing.
Spider Assembly
Begin assembling the turntable with the spider, or the base frame that locates all the supporting wheels. The first step is positioning the center Hub piece. You should already have attached the Pivot and the (2) Shims to the Hub, as described in the previous section. Layout perpendicular lines on your floor intersecting where you want the center of the turntable to be. Now use the alignment notches on the Hub to align to your marks on the floor, see below. The hub can now be attached to your floor or deck, setting your center position.
Next, attach the Long Legs (12 total) to the hub. Use 12 Splices and the hardware stack below to attach the legs finger tight - you may need to adjust the position before locking them in.
Now finger tighten the bolts attaching the Short Legs (12 total), Inner Ribs (12 total), and Outer Ribs (24 total) via the Splices (84 remaining). Same hardware stack as above. The spider is now fully assembled with all the connections somewhat loose, and should look like the image below.
Now the spider needs to be leveled. The goal is for the top plate of the Pivot and the top of all of the casters to be coincident to a level plane, or as near as possible. This is a critical step for smooth operation of the turntable.
The first time you assemble your turntable you may need to adjust the mounted height of the Pivot. The assembled height of each Leg with Shims, and casters attached should match the assembled height of the Pivot, (2) Shims, and Hub. If variances in plywood thicknesses cause differences in their assembled heights, then you will need to adjust. It's easier to adjust the Pivot’s height since there’s only one of these versus (96) casters. Once the assembly heights are evened out, you are ready to get leveling in earnest.
Begin by placing a level on top of the Pivot’s top plate. Spin the top plate around and check that the top plate remains level through rotation, and if not shim underneath the Hub as needed. Now put your laser level on the top plate of the Pivot and aim it out radially along one of the Long Legs, which will be the first row of casters to be leveled. Take a measurement from the top plate of the Pivot to your laser beam; this will be the offset height. The offset height will be your target distance between the top of each of your casters and the laser beam, and making a story stick with a block at this height can save some time.
Now shim the first Long Leg so that the top each of the (4) wheels is the offset height away from the laser beam. Attach that Long Leg to the floor. Now spin the laser level to the next radial row of casters, which will be one of the adjacent Short Legs. Shim the Short Leg so that the top of each of the (2) wheels is the offset height away from the laser beam and then attach the Leg to the floor. Continue rotating the laser, shimming radial rows of casters, and attaching to your floor until you have worked all the way around the spider back to your starting point. Finally tighten all the splice bolts. Now you have a planar and level bearing surface for your turntable.
Anchoring to the Floor
The Revolver can produce up to 1200 lbf of radial thrust when the machine is pressed into the side of the turntable, so you’ll need to anchor the turntable spider to the floor so it doesn’t move when you tension the Revolver. This is easiest to do by shooting (4) 3/8" x 2-1/2” lag screws with washers through the hub piece and into your floor if made from wood or plywood. Alternatively you can through-bolt the hub to steel framing, or use (8) or more masonry anchors with washers, (2) per corner. Feel free to add holes to the hub as needed to adequately attach to your floor or decking.
You may also decide to attach the spider legs to your floor with screws. This is less a concern of resisting the lateral thrust of the Revolver and more to prevent your shims from wiggling out from under the spider legs over time causing leveling issues and unwanted noises.
Cable Path
Run your M12 8-pole encoder extension cable from the Pivot to the location the Revolver will be installed. A little cable management now will go a long way later. Add a few zip tie blocks to route the encoder extension cable along a spider leg and away from any wheels. Although the Revolver will not be installed yet, this is a good time to bring it over and connect the encoder extension cable to test the encoder signal. Plug up your Revolver and Stagehand and make sure that you are getting counts from the encoder and that they are counting in the correct direction (increasing counts for clockwise turntable motion, and decreasing counts for counterclockwise motion). This will be harder to troubleshoot once the lids are installed.
If you have a Slip Ring for your Pivot, this would be an excellent time to run your cable from the junction box on the base plate out to your power source.
Lid Assembly
The next step is to begin putting the lids on the turntable. The lid is composed of (2) layers of 3/4" plywood (the lower layer is 1 and the upper layer is 2) and the Drive Rings at the edge which are (4) layers of 3/4" plywood. Refer to our animation of this process and the 20' Turntable Template Assembly Drawings.
Assemble the lids in this order:
Attach Lid 1-1 and (2X) Lid 1-2.
Attach Lid 2-1 and make Lid to Pivot connections (5/16” allen key) then loosely make Lid connections (#3 Phillips bit).
Attach (2X) Lid 1-3 and (2X) Lid 2-4 loosely making Lid connections (#3 Phillips bit)
Attach (2X) Lid 1-4, (2X) Lid 1-5, (2X) Lid 1-6, and (2X) Lid 2-2 loosely making Lid connections
Attach (2X) Lid 2-3, (2X) Lid 2-5, (2X) Lid 2-6, (2X) Lid 2-7, (2X) Lid 2-8 loosely making the rest of the Lid connections and Drive Ring connections. Once all the bolts have been threaded into their t-nuts, go through and tighten all the bolts.
Again check out our drawings and assembly animation to guide you through the assembly process.
Now your turntable is assembled, with one or two folks you should be able to spin the turntable and ensure its moves smoothly throughout its rotation.
Mounting the Revolver
The last critical assembly step is to mount the Revolver. You can attach the machine to the floor via the (7) ⌀7/16” mounting holes, see below. Choose appropriately sized fasteners to handle the up to 1200 lbf of radial thrust when the machine is pressed into the side of the turntable. 3/8" x 2” lag screws with washers are a good choice. If you cannot anchor to the floor or decking, you will need to attach the Revolver to the turntable spider, which can be accomplished by attaching both to an additional layer of plywood beneath.
Additional Steps
Banding the Edge (Optional)
An optional construction detail is to add a thin layer of aluminum or steel to the exterior drive edge of the turntable. This accomplishes a couple things: 1) creates a smooth and durable bearing surface for the Revolver drive wheel and 2) gives a little more stiffness to the edge of the turntable.
1/8" or thinner aluminum or 1/16” steel can easily be bent to the curved edge of your turntable without heating or roll bending. 1/8" x 4" aluminum bar, as detailed in the Bill of Materials section, works nicely as a banding material. Painting the aluminum banding (no matter the thickness) will improve the grip of the drive wheel.
Alternatively, if you have access to roll-bending equipment, then some 1/4" x 4” bar can give you additional stiffness at the turntable edge. It’s often easier to install if you slightly overbend the pieces to the radius of the turntable, this way you push in at the center of each banding piece rather than trying to push in both ends.
The 4” height of the bar provides some vertical compliance for the 3” tall drive wheel. Keep in mind that by sourcing the bar from your local metal supplier, you may be able to get longer bar lengths (20’ or longer commonly available) and decrease the number seams in your banding.
Be sure to account for the increased diameter of your turntable by double the banding thickness, particularly if you are also constructing surround platforming for your turntable. The CNC cut files can be adjusted by offsetting by your banding thickness on the perimeter pieces if you need to maintain a true 20’ diameter.
To attach the banding to the turntable, drill and countersink holes into the bar for horizontal screws going into Lids and Drive Rings. Ensure that no screw heads are proud of the banding, as they can push the Revolver drive wheel away from the turntable edge creating poor traction and worse can rip chunks out of the rubber drive wheel. Try to get the tightest seams possible, as any gaps in the banding can cause poor traction and motion.
Adding A 3rd Lid Layer (Optional)
If you anticipate putting particularly heavy loads on your turntable. Then you can add another layer to the lids to increase the turntable stiffness. Simply cut another set of lid layer 2 pieces (13 sheets of ¾” plywood), and install this 3rd layer rotated 90 degrees on top of the layer 2 pieces. You will need longer hardware for the Lid connections and Drive Ring connections to attach this additional lid layer.
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