In this second post about the Stanley #2358A miter box, I'll try my best to describe the workings of the swivel and locking mechanisms. Many of the pictures are with the box upside-down, so be aware that when I use words like "above" or "lift" or "raises", the actual meaning could be the opposite when the box is upright.
|Stanley #2358A with new sacrificial floor board|
|This bottom view shows where the swivel mechanism bolts to the main casting|
|Swivel mechanism removed. The grease in the "track" was built up over time.|
The grease only needs to be on the raised surfaces.
|When tightened, the bolt and washers keep the swivel arm a very small distance|
from the main casting, allowing it to swivel.
In the first picture above, just below the front post is the handle that, when squeezed, allows the swivel arm to move. The following picture, with the miter box upside-down, shows the handle mechanism on the underside of the swivel arm.
|The miter box is upside down - this is a view of the underside of the handle|
The two screw heads at right provide a stop so that the handle won't go any higher. The screws capture springs that return the handle to its stopped position.
|Showing the springs that return the handle to rest position and stop it going further|
|With handle squeezed, the springs compress|
|When handle is squeezed, a tab on the inside of the handle moves an arm (see pointer)|
that turns a horizontal barrel that raises/lowers the pin in the vertical brass barrel
In the following photos, I'll take apart the mechanism to show the component parts, and try to describe what each of them does.
Let's start at the back end of the handle area. The handle is held to the casting with two screws, shown by the red arrows. The yellow arrow points to a short, slotted threaded rod, the purpose of which I'll get into later.
|Back end of handle area|
|With the short threaded rod removed|
When that threaded rod is removed, you can see the top of the barrel that is aligned vertically in the casting. Cutting across that barrel is another barrel oriented horizontally and you can see a part of it through the vertical barrel.
When I remove the two screws (see red arrows, above) and take off the handle, you see that the horizontal barrel has a split tab that fits into a slot on the inner edge of the handle. When the handle is squeezed, the horizontal barrel is turned.
|Attachment of handle to casting. Vertical arrow points to the slot in the handle,|
horizontal arrow points to the tab on the end of the horizontal barrel.
The following two pictures (side view) show what happens when the tab is rotated. I've cheated a bit here - the two positions are not an accurate depiction of when the handle is installed.
|When handle is squeezed to release the swivel (the tab would actually be more horizontal)|
|When handle is released to lock the swivel (the tab would actually be rotated clockwise more)|
Note what happens to the bottom part of the vertical barrel - the part that extends below the casting. When the handle is released, the vertical barrel is pulled into the casting.
|Here it is in action. The dental tool is pointing to the part of the vertical barrel that extends|
from the casting. Note how it "clamps" on the lip of the main frame of the miter box.
That part of the barrel that extends from the casting is sort of a "lock" for the swivel angel setting. Here are the individual parts of the mechanism.
|A: horizontal barrel, B: vertical barrel with clamp, C: slotted, threaded rod|
|How parts A and B interact within the casting|
The horizontal barrel is positioned such that as it rotates, it lifts and lowers the vertical barrel. The threaded rod, when it is tightened all the way, rotates the horizontal barrel in such a way that it locks the swivel mechanism. As far as I can tell, this is only important when the user wants to lock in an angle that is not one of the preset angles.
OK, now it's time for the part that lifts and lowers the pin that fits into the holes for the preset angles. This includes the brass barrel, the spring-loaded pin and the horizontal barrel / arm mechanism.
|D: brass barrel, E horizontal barrel with arm|
|The brass barrel with spring-loaded pin|
In the first of these three pictures, you see a screw just above the arm. There are two of these - one on each side and they are shown in the second picture, close to their normal orientation relative to the brass barrel. When they are tightened in the two detents of the brass barrel, they keep it in proper position. The first of the three pics above makes it look like one of them might be a stop for the arm of the horizontal barrel, but that's just coincidence - the arm stops anyway just before hitting the screw.
The arm is actuated by the handle - a small tab on the inside of one fork of the handle is positioned to move the arm when the handle is squeezed (see the eighth picture in this post). The barrel that the arm is attached to turns and engages the carved out area in the head of the pin. This next picture shows how it works - sort of.
|When the arm and barrel rotate (counter-clockwise), the pin retracts (to right) into the brass barrel|
Here's what happens (following two pics show handle end of casting in proper upright orientation):
|With the handle in neutral position, the pin (red arrow) protrudes and can engage|
with any of the preset holes on the underside of the miter box
|With the handle squeezed, the pin retracts, disengages with the preset holes|
and the swivel is free to move to another location
BTW, the holes for the pre-set locations are for angles that were commonly used for equilateral structures that have 3, 4, 5, 6, 8, or 12 sides. The holes furthest from 90° are at 30°, used for making a 3-sided frame. Those locations are not marked on the top of the box. These positions are also used for storing the box in its most compact configuration.
|Underside of the box showing the holes for preset angles|
|But what if you want to cut at an angle other than the presets?|
I noticed that if I tried to cut an 80° angle (for example), the swivel could move during the operation because the pin was not in a hole for a pre-set angle. But I found that the swivel could be locked using the threaded rod mentioned earlier.
|Screwdriver ready to engage the threaded rod to lock a non-preset angle|
Unfortunately, that means getting under the box to lock the angle. I'd guess that many miter boxes are clamped or even bolted to a table, making this a pain in the ass. I guess I'll see if it matters.
Well, that's it for the Stanley #2358A miter box. It's a nice tool to have, but again, time will tell if I actually use it in my small shop.