Alignment Question

[paradisecs]

The USC-2 I've brought back to life is working great except for on thing I just noticed, thicker records are rubbing on the rack when playing. 

My records I used when going through the alignment and various clutch and pickup adjustments were all thin so I didn't key in on it.

The pickup arm is dead center of each record slot so I don't think it's a rack alignment but I'm not sure.  Is there a clutch adjustment that can affect this positioning?

Stephen

[Ron Rich]

Stephen,
Play both sides of the same record--still rubbing on the same side of the separator ? When one rubs, does it rub on the inside ( TT side) or the outside (clamp disc side) ? Ron Rich

[paradisecs]

I found my flattest fat record and tried in several different slots. Both sides are rubbing on the right side of the slot (clamp arm side). What is TT? It's like the mech is half a tooth out of position even though the transfer arm is dead center.

Stephen

[robnyc]

Stephen, if the misalignment has been on the T_T (turntable) side the thrust bearing adjustment would have been indicated, Since it is on the other end, there really isn't any proper way to deal with this other than adjusting the magazine followed by a touch-up of both tormat and lift arm.

I've built up a number of mechs made from disparate models/years, in those cases you just have to take a holistic approach and do all adjustments. Likewise, if a mech has been tampered with -expect some surprises along the way.

One "Gepetto" approach I witnessed was to back off the lateral thrust adjusting screw on the t-t shaft and thus allow the clamp to push the t-t slightly towards the motor end when clamped. I'm sure Ron will appreciate my mentioning that little gem...:-)

Do it right, it is unlikely you'll ever need to revisit it.

Rob in NYC

[Ron Rich]

Hi Stephen,
Rob's correct ( don't dare call him "right" !). If the TT thrust bearing is properly adjusted (which I suspect it is), then someone has either removed/replaced the clutch incorrectly, or the record rack has been moved ( If you have a copy of my Seeburg Mechanism Guide, read how I align the clutch). Ron Rich

[paradisecs]

This machine had sat for years with the cover off in a garage where 40s & 50s cars were restored. It was caked full of bondo, sanding dust, grease, and who knows what else. The guy said they even worked on the jukebox sometimes but that it never worked. Who knows what they did to it before I got it, nearly every adjustment screw on the mech had been backed out and left loose. So it's possible I have something in wrong but the clutch seems aligned up correctly. How do you replace the clutch incorrectly? Is it something visible?

I took the rack completely off along with tormat, replaced contact block (broken arms), and just about anything that didn't require full disassembly. I didn't take the clutch apart piece by piece but it was removed and deep cleaned. I did not remove the cam assembly (I'm not that crazy). I even pulled the track out and cleaned it.

I'll go back through your section on adjusting and see if I missed something. I'm starting to have the adjustments memorized so practice is good.

Adjustments I have done:

Thrust screw
Clutch 1-4
Trip Solenoid
Safety Lever
Guide Rollers
Magazine Horizontal
Tormat Position
Readout Contact Block 1-3
Trip Switch Position
Detent Switch Contact and Pressure
Reversing Switch brackets
Reversing Switch Contact and Pressure
Rubber Bumpers
Cam Switch
Selection Indicator Switch
Adjustment for record hitting needle (Robs method)


I listed the above more for mental note to myself than anything else. I've spent well over 100 hours learning on this machine and it has been frustratingly fun. I've taken it apart more than I care to admit but I can perform tasks now in minutes that originally took me hours. I'm just glad you both are around to give advice when I do something stupid.

Stephen

[robnyc]

Sept 23, 2018 12:20:46 GMT Ron Rich said:

Hi Stephen,
Rob's correct ( don't dare call him "right" !).  Ron Rich

-You are so right :-)

Rob

[paradisecs]

Ron,

I read through the mech guide again about the clutch. Are you thinking that removing the small segment of track and adjusting the mech over one tooth will do the trick or am I looking at the wrong thing?

Stephen

[Ron Rich]

Stephen,
If no one has re-positioned the record rack, yes, you can remove the short track section, as stated in the guide. In your case, since you removed the rack, you need to get a "flat record", and set it near the center of the rack, put it in play position with that record CENTERED between the two separators--slide the rack to do so. Once done, the record rack should be somewhat centered in the screw holes that hold it to the base. If the rack is not "somewhat centered" on the base, the clutch is way off--slip it one tooth one way or the other to achieve that goal. Once that's correct,you need to re-align the lift arm, and re-align the read out frog, as per the manual. The above assumes the TT thrust bearing is correctly adjusted --- Ron Rich

[paradisecs]

What all does the TT thrust bearing do? It seems to crop up in much of what you say but I don't see anything written on what it actually does. It's not the same as the thrust bearing on the cam, correct? And how do you know whether or not its adjusted correctly?

Stephen

[robnyc]

Stephen, the thrust bearing on the T-t shaft simply hold the position of the flywheel so that a record remains centered whether A or B side is played. On the older mechs that adjustment did not exist, it was just a plate across the sleeve bearing hold in a ball bearing. Over time a lot of L-R slop occurs and, in some cases, records will start to rub on the dividers.

Correct adjustment is just to eliminate any noticeable shift while keeping the shaft free to rotate.

RobNYC

[Ron Rich]

Stephen,
See the Service Manual for the exact, correct info, on this thrust adjustment--but as always, remember that the manual was written when the parts were new, and does not compensate for ware. If not properly lubricated, sometimes the thrust ball bearing (.187) freezes to the shaft and wears down--If that happens, it MUST be changed, Other times the "case hardened" screw wears so there is a hole in it. It should have a flat surface against that ball. Ron Rich

[paradisecs]

Thanks for the info. I'll check the manual again. I looked and only saw the adjustment for the bearing on the clutch. How much play side to side should there be?

Stephen

[Ron Rich]

Stephen,
Please--RTFM !
Ron Rich

[paradisecs]

Okay, I finally found it....in a different copy of the manual. The one I had printed didn't have that page and I hadn't noticed the numbering was off. I found it in an LS1 manual though. I was able to align the rack again and that seems to have done it.

Stephen