In the first article we took the simplest approach to mount the light to our camera. We passed a bolt through the entire body of the light and screwed it into the camera tripod mount.
We also showed how you can place the bolt inside the housing when you are not using it.
Well, what if you would like the bolt to stay in its place and act more like a built in knob then just some screw?
You will need to use something on the other side of the plastic wall nearest the bolt head to keep it from falling out.
Before we go any further we have an observation to make.
The bolt is passing through two holes in the housing. One of those holes is on a door that slides open to grant access to the batteries. If you lock the bolt in a position so that the bolt passes through both holes you would essentially be locking the door closes and actually wouldn’t be able to slide the door on in the first place
So the method you choose should either allow the bolt to slide down far enough to release the door, or be semi-permanent so the bolt can be pulled out of the way when you need to operate the sliding door.
There is also a consideration to make. Do we want the bolt to be completely removable? Or can we accept the bolt being permanently installed into the body of the light so long as it doesn’t affect operation?
So finally there are some design requirements here you’ll need to look at before selecting your solution
Requirement 1- The bolt shall not fall out of the battery housing.
Requirement 2- The bolt shall rotate freely to engage the threads of the camera mount.
Requirement 3 - The bolt shall not lock the battery door permanently
And one variable requirement.
Requirement 4 - Does the bolt have to be removable?
Here are a few ideas that come to mind.
A- Insert the bolt into the main body of the light and slip a short hollow plastic tube over the thread. Pull the bolt down until it clears the battery door and no longer obstructs movement. When not in use the bolt will simply hang away from the body, partially in and partially out of the light housing. This is not permanent because you can always pull hard on the bolt to free it from the plastic tube. And if you want it to be permanent you can glue the tube to the screw.
B -You can copy method A but use shrink tube instead of a plastic tube. If you heat shrink it in place it would function the same way. But you’d have to be careful to know exactly where to place the tube, and unlike method A this is pretty permanent. You could probably pull really hard on the bolt to remove it completely, but you’d still have a tough time removing the shrink tube from the bolt.
C- You can use a retaining ring. The ring’s outer most diameter would have to be smaller than the battery compartment so that it doesn’t restrict rotation or accidentally unscrew in use. You can either press the ring down to place or screw it on like a nut.
For my camera I chose to use the retainer ring on the door as shown below.
but I have to be careful not to hit the LED leads as I open the door. It would have been better if the hole was over to the end more.
You can find retainer rings at Home Depot. They come in packets of 2pcs for 40 cents. So 20 cents per piece.
D – You can use an o-ring. Which is basically a thin rubber ring that can be rolled down the bolt to the appropriate position.
E- since you might not have the above items handy you can also try using a twist tie. It wont be as strong as the other options but it’s quick. Cut about 1 inch of length and wrap it around a 1/4 inch bolt. Then remove the ring you made and squeeze it between your fingers to shrink the diameter. Then slide your bolt into the light housing and slide or screw the twist tie ring onto the bolt in the proper location.
see the photo set for a guide
If you can find a spring that fits around the 1/4 inch screw and sits between the retaining ring and the plastic wall you would have a spring loaded thumb screw. So you would have to pull the screw head and compress the spring before opening the battery door.