Adjustment #4: Micro Switches (w/two videos)

Micro Switch Adjustments, including:

• #3, Cancel Relay Micro Follow Switch  
• #4, Safety Micro Switch 

Seen below are two switches:

• The #3 Micro Switch, also referred to as the "Cancel Relay Micro Follow Switch", and
• The #4 Micro Switch, or the "Safety Micro Switch"

The #3 switch is located on the left (outboard), the #4 switch is located on the right (inboard), and both switches are operated by cams on the Gripper Drive Shaft.

Obviously both of these need to be "timed" to work with the Grip Cam Limit Switch properly, and thus that procedure needs to be completed before adjusting these two switches (see previous post for procedure). Also, if the Grip Cam Limit Switch is moved, replaced, or otherwise adjusted in any way, timing and operation for both of these switches will be affected.
 
Recall that the Grip Cam Limit Switch removes power from the Gripper Arm actuator (stops the Gripper Drive Shaft from rotating), and also note that both of these switches are mounted to that same shaft. This, it should only stand to reason that these switches need to operate at some point in time before the shaft stops turning...and that's exactly what happens!

Operation:

• The #3 switch closes the circuit for the Selection Lever Reset Solenoids on the Carriage Assembly (one each front and rear), and completes the Cancel Relay circuit, which locks the Cancel Relay "in" should power be interrupted for any reason.
• The #4 switch ensures that the Magazine Motor does not operate while the Gripper Arm is in any position other than "home".

The IOM calls for the adjustment of these switches to be performed while referencing the same Stop Pins mentioned in the previous post. However, because I prefer to not use the Stop Pins when adjusting the Grip Cam Limit Switch, I have found I achieve better results when I simply adjust them according to what I call "Actual" conditions, and that's what I am going to show here. If you have a copy of the IOM and prefer to use their method, so be it! But be aware that regardless of which method you use (IOM or Actual), you will need to consistent, as the switches don't always allow for a "mix 'n match" of the two methods.

Since it is the easiest to understand, and thus explain, I'm going to start with Switch #4. As stated directly above, the purpose of this switch is to open the circuit to the Magazine Motor so that it cannot operate any time the Gripper Arm is not in position above the Record Magazine. In other words, this switch operates so that any time the Gripper Arm has moved from this position, the Magazine Motor is effectively shut off.

In my opinion, adjustment of Switch #4 is most readily performed with the Gripper Actuator removed (as seen in the video) so that the Gripper Arm Shaft may be manipulated manually. The procedure is to manually run the Gripper Arm Drive Shaft through a full "cycle", and adjust this switch so that it closes (you will hear the click) just before the Grip Cam Limit Switch opens as the Gripper Arm is releasing the record back in the Record Magazine. If the Grip Cam Limit Switch opens before the #4 switch, the shaft will simply stop turning, and thus the switch won't have a chance to fall into the groove in the cam.

Note that you must run the mechanism through the full cycle during this procedure, as the Grip Cam Limit Switch must be in the proper position in order for this to work. If you simply turn the shaft, grab a record, raise the Gripper Arm a little, and then put the record back, this won't work, as you haven't reset the Grip Cam Limit Switch.

As a final test, the switch should now "break" (operate) when you manually turn the shaft at the beginning of a simulated cycle.

Once switch #4 is properly set-up, adjustment of switch #3 is downright simple. As mentioned previously, this switch has several functions, one of which is that is enables/energizes the Selection Lever Reset Solenoids (which are de-energized/shut-off by the Grip Cam Limit Switch). Checking the operation involves little more than listening to the timing of these solenoids (more on this below).

I didn't mention this in the video, but my method of adjustment is as follows: Rotate Switch #3 into position so that there is a 1/8" gap between the two cams in the groove shown here, and tighten the set screws.

Rockola's IOM describes this adjustment this way: "Loosen the set screws in the #3 micro cam and rotate it so that it is flush to the adjacent #4 micro cam, and the gap distance between the two interlock edges is 3/16 of an inch". Sure, sounds simple enough. But since the edges are rounded, where exactly is this dimension supposed to be measured? At the beginning of the radii, or the end?

I prefer to use the 1/8" allen wrench method, making sure it's bottomed-out onto the shaft.

Thankfully this adjustment isn't as critical as the previous, and most of the time the 1/8" allen wrench setting will suffice.

To manually check this setting/adjustment, while operating the Gripper Drive Shaft manually, turn the shaft so that the Gripper Arm rotates down into the Play position, but with the record still in its grasp. While continuing to rotate the Drive Shaft so that the Gripper Arm begins to open, Switch #3 should fall into the cam and "click" at some time prior to the Grip Cam Limit Switch.

If things look good, power the unit up, check your setting/timing against mine (time stamp 3:50 in the second video linked below) and adjust accordingly.

Having said that, I can say with absolute certainty that I have this switch adjusted exactly the same as the 1452 we had when I was a kid, as this is a sound I have never forgotten, seeing how it was burned into my memory during my young, formative years!

Due to time constraints (length of video), I broke-down these adjustments into two videos, one showing the actual adjustments, and the other showing operation and some other details.

Link to first video (adjustments): https://youtu.be/SrCXQmsMU6s

Link to second video (proper operation): https://youtu.be/hYcGSJD5hzc