Hi all
Casters have always been a burr under my saddle, so over many years of being a TD, I have come up with some best practices that work well for me. Maybe some of these will help you out.
First, trace the path of force from the load on the wagon to the floor. If casters are attached to the underside of the lid of the platform, the force travels from the load to the lid (compression), then to the frame (compression), then back UP to the lid near the corners (tension), then back down to the caster (compression) and then to the floor (compression). The weak spot in this path is the tension between the lid and frame near the caster location. Have you ever seen a lid lift off the frame near where the casters are located? That's the result of the tension trying to pull the lid off the frame. (BTW - The same thing applies to legs that sit inside the frame and push up on the lid). For this reason, I always attach my casters to the underside of the frame, or at the very least to a caster plate that is attached to the frame using a shear joint.
For quantity of casters, remember that casters are essentially legs that roll, so if you would six legs under that platform, use six casters under that wagon.
As some have already mentioned, consider the path of the wagon and choose the type of casters that best serve that motion path. If the path is random (moving any direction at any time), use a version of swivel casters. If the path is a straight line, avoid the use of swivel casters and migrate toward straight casters so they don't have to "throw," or swivel to reverse direction to go the other way. For example, never ever ever use swivel casters on a revolve, because when they "throw," they will either rip themselves apart or scrape/gouge the stage floor or the under side of the revolve when they throw. Some other options are "triple swivel casters" that have three swivel casters mounted to a swiveling plate - this arrangement allows for smooth random motion AND direct straight line motion with no throw because the throw is absorbed by the swivel plate. Another effective option is a rotacaster, which is a straight caster with small offset bearings around the circumference of the wheel. This allows for an easy straight line motion with off-line motion that is a little more difficult but very little effort compared with trying to move a straight caster off-line. One great advantage to the rotacaster is that they can be placed right next to the edge of the frame so eliminate the overhang. I am currently using rotacasters on two large wall wagons that move along linear paths during the majority of the show, and at the end, they swing open like french doors.
The final area is how to stop the wagon from moving (which was a great frustration for me in the 1980s and I fixed it then and never looked back). I never use brakes because they simply never work right. If the wagon is only carrying scenery and actors never interact with them (and never transfer their motion to the wagon), I will hard mount the casters to the wagon and move on. However, if an actor steps on the wagon, leans against the wagon, or interacts with it in any physical way, I treat the "castered" condition as the temporary state instead of hard mounting casters and making the "braked" condition the temporary state. I have several devices I use to mount the casters on a frame that pushed out the bottom of the wagon to lift it slightly off the floor onto the casters when motion is needed, but the entire wagon sits on the floor in its playing state. Granted it is nowhere as easy as bolting on some casters and brakes and crossing my fingers that they don't malfunction.
OK - Thats my two cents worth. Hope it helps :-)
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Tracy Nunnally
NIU - Professor/TD/Area Head (
tnunnally@niu.edu)
Vertigo - Owner/System Designer (
tracy@getvertigo.com)
ETCP Certified Rigger/Trainer/Employer
I.A.T.S.E.
DeKalb, Illinois
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Original Message:
Sent: 10-12-2022 11:02
From: Stewart Hawk
Subject: Stage wagons
We generally used a 4" caster, base to edge of the wheel, for wagons made out of 2x4's with 3/4" plywood tops. This gave a 1/2" clearance and it was difficult to see the wheels.
I also found that if I used a 1x3 "L" board spacer in the corner to guide placement of the caster we had plenty of room for the caster to move 360 degrees and still gave stability to the wagon.
For a 4x8' wagon I would use 6 casters, 4 in the corners, 2 in the middle of the long sides. For a 4x4' wagon one in each corner.
Stability gets tricky for wagons smaller than 4x4'. In those instances I would use a small 1x4" block, as a mini leg, in the corners a quarter inch short of the stage deck. This prevents the wagon tipping.
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Stewart Hawk
Washington State Thespian Co-Chapter Director
206-465-4568
stewart.hawk@gmail.com
http://wathespians.org
Original Message:
Sent: 10-11-2022 11:35
From: Ginnie Bullis
Subject: Stage wagons
This may be rudimentary to some, but can I get advice on placement of castors on a wagon so that the wheels don't show? Last show they were placed awkwardly and kept hitting the sides and were clearly visible. Should the castors be placed near edges? Center? We have only volunteers helping and I'm not trained in stagecraft. Any advice will be greatly appreciated.
Ginnie Bullis
C. Milton Wright High School
National Board Certified Teacher English
Drama Director/Teacher
Speech & Debate Coach
STARS/SADD Sponsor
410-638-4110
ginnie.bullis@hcps.org