Friday, November 22, 2019
Thursday, June 6, 2019
It's up and running! (Kinda...)
(Note: This post is still a "Work In Progress", and I will make changes and modifications to it as time permits.)
Monday, April 22, 2019: The "official" start-up day!
(work involved pre-startup to be inserted here)
After setting VTF, and making all of the last minute/minor adjustments, I asked my wife if she would like to make the first selection! The video of her selecting the first "official" play of the 1452 may be seen here:
https://youtu.be/pdc88mPsL5o
As may be seen in the video, everything seemed to work just fine, but sadly the turntable was too fast. Talk about conflicting emotions- the joy of seeing, and hearing, the 1452 make music after all these years, combined with the disappointment of the TT turning "too-fast". I may sound "matter of fact" and unemotional in the video, but truth be told I was riding an emotional roller coaster at this time, and I'm really surprised this doesn't come-out in the video.
However, the speed issue really bothered me, so immediately after this video I tore apart the TT assembly, and even though they measured almost identically to each other, I replaced the new/replacement Idler Wheel Assembly with the OEM unit (RO P/N 17148), thinking I may have received and installed the wrong Idler Wheel somehow.
Video from the second attempt is here:
https://youtu.be/sfhZSWreBLQ
As different idler wheels produced the same results, obviously the issue did not originate here.
So here's my brain talking to me right about this time:
- "Then again, the TT runs off an asynchronous shaded pole motor, and the speed of those is always based on the incoming frequency, so that can't be the cause!"
- "I wonder if I have two bad idler wheels?"
- "I wonder if I can still buy another wheel?"
- "I wonder if the Idler Tensioner Spring could be the cause of this?"
- "Or as a test, I wonder if I could modify an old wheel to correct this speed issue?"
In the meantime I grabbed an old wheel I had lying around and chucked it into a drill, thinking I could sand and/or grind down the smaller
Monday, April 22, 2019
Test post for misc items
What does this rubber ring "do"? There is one on each side of the Record Magazine. What purpose does it serve, and/or what does it (they) do?
Monday, March 25, 2019
Yesteday was a "Big Day"!
Recently I realized I have reached the point where all of the adjustments have been made, all of the videos have been taken (some, admittedly, somewhat crude and/or hurried), and there's little left to do except install the mechanism into the cabinet! However, the cabinet is in the Family Room, the mechanism is on the test stand in the basement, and my wife isn't comfortable with the idea of helping me carry it up the stairs. So we reached out to her brother Dan, who, as it turns out, was more than happy to help.
Sunday (yesterday) morning I prepped the mechanism for moving (unplugged everything, etc), and tore-down the top part of the cabinet:
When Dan arrived I was just tidying-up some loose wiring:
And a few minutes later we tested the weight and balance:
A quick lift (it didn't weight all that much), and we headed for the stairs:
We had to tip the mechanism a little in order to get it up and over the top of the front panel:
And of course when we got it in place we had to do the Old Man Fist Bump!
Dan lifted each side of the mechanism while I installed the isolation springs:
Then we re-installed the Dome Assembly:
And since my curiosity was killing me I just had to throw-on the front door and plug-in the light:
After dinner I re-installed the side glass panes, the back panel (backsplash), and installed a new pricing sticker on the front glass. Here's how it sits right now, in all its fingerprint-smudged glory:
It's getting mighty close to coming alive!
(Thanks for all of your help, Dan!)
Adjustment #6: Toneam Switches & Adjustments (w/video)
Tonearm Adjustments
Jumping right into things, tonearm adjustments are as follows:
* Set-down position:
According to the IOM, proper position of the set-down position of the tonearm (the stylus, or "needle") is 3/32" from the outside edge of a 7" (45 RPM) record. This is accomplished by adjusting a screw located at the rear of the tonearm (circled in orange below):
I found the outer diameters of the 45's I had on-hand varied so much that this measurement was almost hard to nail down, so I made this adjustment based on a "best average" across all of the 45's I had installed in the unit.
* Cut-off position:
According to the IOM, the record cut-off position is 2-1/32" inches from the center of the hole measuring outward. I found this somewhat cumbersome to measure, so once again I simply used a "real world" methodology, and made this adjustment using the old 45's I had installed in the mechanism to ensure that the tonearm switch closed just before the stylus reached the innermost cut-out groove.
The Tonearm Switch is seen here:
Notice there is a small lever (yellow arrow, below) which pivots with the tonearm (it is part of the rotational assembly), and this lever pushes against a "bumper" located on the rearmost Tonearm Switch lever (circled in orange). When the tonearm reaches end-of-play, this lever pushes against the "bumper", which closes the Tonearm Switch.
Although it seems rather crude, adjustment of the cut-off position is accomplished by bending this lever (I used a small needle-nosed Vice Grips, as seen in the video).
* Trip Dog lever:
After making the cut-off position adjustment, one must also adjust the Trip Dog. Essentially the Trip Dog is almost like a "check valve" which, according the IOM "....is a safety device to prevent re-playing the same record by jarring the tone arm back against the record". (Much like how people use a little "English" when playing pinball, apparently people attempted the same thing with jukeboxes back in the day to get their records to play over again!)
Here's a shot of the Trip Dog (circled in orange):
Adjustment is made via these two screws (circled in green):
The adjustment is a little finicky, but what you want to accomplish is to see the Trip Dog "release" just before the Tonearm Switch makes/closes. In other words, the Trip Dog needs to release before the tonearm reaches the lead-out groove (cut-out position), but after the record has completed playing. (See time stamp 4:07 in my video, linked below).
* Tonearm Height:
The height of the tonearm needs be adjusted so that the stylus just touches the flocking on the turntable. I can't make this adjustment yet, as I'm still waiting on my flocking supplies (I had the turntable re-chromed), but I think I got it pretty close. I don't have a picture of this, but I mention it in the video.
Tonearm height is adjusted via this stud here (red arrow):
* Tonearm "Liftover Height":
When an even-numbered selection is entered, the Gripper Arm will rotate to the right, and will come to "rest" in-between the Tonearm and the turntable. Seen in another way, in order for the stylus to play the record, the Tonearm will need to reach over the Gripper Arm, and the "liftover height" (my term) needs to be adjusted so that there is between 3/16" to 1/4" of clearance between the bottom of the stylus and the top of Gripper Arm as the Tonearm moves over the Gripper Arm.
Here's an old picture I dug-up that may help explain what I'm talking about:
Tonearm "Liftover Height" is adjusted via this stud here (blue arrow):
* Vertical Tracking Force:
Vertical Tracking Force is adjusted by inserting a 5/64" Allen wrench into the hole located at the rear of the Tonearm:
Which will engage the setscrew seen here (blue circle):
This setscrew applies pressure to the "Tonearm Spring" (the copper-looking part), and adjustment is simply down/in/CW for more VTF, and up/out/CCW for less VTF.
Link to video: https://youtu.be/czlAFelgHHU
Sunday, February 3, 2019
Adjustment #5: Carriage Assembly (w/video)
Carriage Assembly Adjustments
A few Posts back I mentioned that, as a kid, the jukebox we had "ate" records, and I distinctly recall records scraping along the sides of the Record Keepers as they were going into, and out of, the Record Magazine. I'm almost certain that this adjustment, had it been performed properly, would have saved most, if not all, of the 45's I had as a child.
According to the IOM, the Carriage Assembly has three functions:
- Search for a Selector Lever in the "Play" position, and upon finding one, stop the rotation of the Record Magazine motor,
- Align (or "index") the Gripper Arm to the proper record,
- Return the Selector Lever (see item #1) back to the normal position.
There are two rows of Selector Levers located around the circumference of the Selector Unit, the levers in the front row correspond to odd numbered selections, and the levers in the rear row correspond to even numbered selections. Regardless of row, a lever in the innermost position is considered to be "Off", while a lever in the outer position is considered to be in the "Play" position, as seen here:
On the bottom of Carriage Assembly are two spring-loaded contacts- one for the odd (front) levers, and one for the even (rear) levers (circled in yellow):
As the Carriage rotates over the Selector Unit, it will immediately stop the Magazine Motor when a contact finds a Selector lever in the Play position by short-circuiting the Magazine Motor armature (the Selector Lever in "Play" electrically "grounds" the motor). In the IOM this is referred to as "Indexing the Gripper Arm".
Also note in the picture above that these contacts are mounted in separate "blocks" that can be moved left to right independently. I will refer to these blocks as the "front/odd block" and the "rear/even block" in a minute.
On top of the Carriage are 4 screws that hold these blocks in place- the two towards the front (yellow) are for adjusting the odd selections, and the two at the rear (red) are for adjusting the even selections.
Also, there are allen head bolts located on each side of the Carriage (no picture, see video) for making minute L-R adjustments.
The adjustment procedure is a little tedious, and one must be finicky when performing it, otherwise damage could occur to the records. Be thorough and take your time here.
The procedure:
* If the Carriage Assembly has been replaced, rebuilt, cleaned, or in any other unknown condition, the "rough" location (L-R) will have to ascertained. Doing so requires removing all of the records, powering-up the unit, and making various selections, both odd and even numbered. The idea is to adjust the 10-32 bolts on either side of the Carriage so that the Gripper Arm is located roughly on the centerline of the record slot in the Magazine when in the rest/home position. You don't have to be exact here, just try get a good "average".
* Once this is set-up, leave the bolts alone! You won't be touching them again.
* After this is accomplished, the Odd selections (only) need to be adjusted. First step is to install some old records, and then select record #1. Note the Magazine rotates in a CW direction when making odd selections (this matters when making the adjustments, and under normal Play conditions the records will Play from #49 down to #1). When the Gripper Arm begins to remove the record form the magazine (maybe about half-way out), shut the unit Off at the Service Switch and note the location of the record with respect to each side of the Keeper on the Magazine. Take notes ("tight LH side", etc), and then repeat this process for the #49 record, as well as one of the middle selections (23, 25, etc). The results should be somewhat consistent.
Here's what I was able accomplish with Record #1 (performing "odd" adjustments):
Note how the gaps on both sides are almost identical.
Depending on where the record is at (too far left or too far right) will determine which way to move the Carriage Assembly, as you are either picking up the record "too soon" in the Magazine rotation, or "too late". See below.
If the alignment is off (the record is not centered in the Keeper), you can correct for this by loosening the two front screws on top of the Carriage (yellow, above), and moving the "front/odd block" either left or right accordingly, as per my notes below. Note that the allen head bolt is to be used for this adjustment, and my advice would be to make small, incremental changes (one-half turn on the allen head bolt) AT MOST before re-checking!
Once the adjustment is set-up for the odd numbered selections, DON'T TOUCH THEM AGAIN!
* The procedure for the even numbered selections is the same, only now the Magazine will rotating in a CCW direction (under normal Play conditions the records will Play from #2 up to #50) , and you will be working with the two rear screws (red, above) on top of the Carriage assembly. Start with record #2, take notes, go to record 48 or 50, take notes, go to record 24 and take notes (etc.) Again, make small changes, be patient, and go slow.
At the end of the video I promised I would post the following information to help clarify this procedure. If you watch the video, here's the info I promised:
Odd Selections:
- Front set of Selection Levers
- Carousel rotates CW, from #49 down to #1
Record tight to the left side of Magazine opening:
- Carriage picking-up contact "too late"
- Adjust carriage to the right
Record tight to the right side of the Magazine opening:
- Carriage picking-up contact "too soon"
- Adjust carriage to the left
Even Selections:
- Rear set of Selection Levers
- Carousel rotates CCW, from #2 up to #50
Record tight to the left side of Magazine opening:
- Carriage picking-up contact "too soon"
- Adjust carriage to the right
Record tight to the right side of the Magazine opening:
- Carriage picking-up contact "too late"
- Adjust carriage to the left
After everything above has been accomplished, Best Practices would dictate that all Selections are checked (odd selections and then even selections), and VERY SMALL changes made to the Carriage so that a "best fit" is achieved for all records.
Be patient. Do this "right", not "right now"!
Link to video: https://youtu.be/QmWMJI2Lm8I
Adjustment #4: Micro Switches (w/two videos)
Micro Switch Adjustments, including:
- #3, Cancel Relay Micro Follow Switch
- #4, Safety Micro Switch
- 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".
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
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