LS1 slow motor speed

[e093116]

Hello, I have an LS1 project that I've played audio through for the first time this weekend. I've noticed that the records are playing a little bit slow, but the speed is relatively consistent. All of the moving parts have been lubricated and move freely, just wondering if there are any adjustments or other factors that I can check before replacing the motor capacitor? The control unit does not have the autospeed option on it, but it is in original condition and has not been recapped (I didn't see any caps that are obviously leaky/blown/bulging).  The reversing switch is in good condition, no pitting, arcing, buzzing, etc.

One thing that I did notice is that the motor seems to hum a little bit louder than my other machines when scanning.  It also seems like the motor is a little underpowered/easier to stall than the other machines.  Are these signs of a bad motor cap?

Finally, is there an end play setting or other adjustment for the shaft/gear that the motor spins through the drive coupler?  I didn't see this in the manual anywhere.  I thought maybe it was too tight and causing the slow speed, but adjusting it looser didn't change anything.  For my final setting, I tightened the set screw until I could feel it lightly bottom, then I backed off 1/4 turn.

On a different note I had a few people over last night and the LS2 project from last week survived it's first real world test.  It actually made me some money, as my friend's wife used her own quarters to play it!

Thanks in advance for the help.

Bill

[Ron Rich]

Hi Bill,
If you have "re-adjusted" the upper trust bearing with the motor coupling connected, you probably do not have it adjusted correctly. This must be done as per the Service Manual, with the coupling not connected. If you did not remove the bearing bracket assembly, you probably should, and check that ball bearing, and the bronze bearing for lubrication--gummy, or the lack of it ( BTW, that bracket, is the only part on the mech that is not interchangeable from mech to mech) If you did not, you should remove the motor, open it and remove the green "gunk"--If you have a copy of my Seeburg Mech Guide, you will find quite a bit there, on slow motors, and how to correctly, re-install a new motor coupler. Ron Rich

[e093116]

Hi Ron, thanks for the recommendations, located relevant info on page 28 of your book.

I found the thrust ball was seized with a ring of goo on it (looked like Saturn when removed), excessive end play in the motor, and missing rubber bumper at the bottom of the motor in the frame.  The motor bearings were clean/good.  Fortunately, I had something very close to the missing bumper in my "rubber parts" bin of spares.  Took about 45 minutes to disassemble/clean/adjust everything which resulted in the motor speed/record playback improving to no longer be noticeably slow!

I am down to two final problems on this machine.  First, I noticed last night that when rejecting after playing the b-side of a record, the cartridge/needle will contact the clamp arm frame when moving from the play position to the scan position.  It looks like there is a clearance notch in the clamp arm frame just for this, but obviously this must be out of adjustment or something might be bent.  I'll have to double check.

Second, I am having trouble getting the record rack/tormat/mech aligned properly.  When I select A1, the mech will stop/play/reject properly, but when I select B1, the mech stops and plays D1.  So I have an offset somewhere that I need to track down.  I did remove all of the relevant items to clean up a previously replaced/spliced in contact block which was poorly done, I did note that all of the wires that were cut had the same color code, so I hooked them up that way without too much thought, maybe I missed one and cross connected the two wires for the contact block...this is the only thing I can think of that would cause the offset.  I'm going to take the record rack off and double check the wiring from the contact block pins to the correct switches and then start over with the adjustment/alignment activity.

Thanks again.

Bill

[Ron Rich]

Hi Bill,
Glad you got it--glad you found the info in the guide ! ( did not know which printing of the guide you have, and since I'm basically lazy, did not want to figure out which page it was, in your guide)
As for the wrong selection problem--I doubt that you have incorrectly wired the frog--most likely either your detent switch is not correctly set (gap, and over-wipe), or the TMU itself is miss-aligned-- Service manual shows how to align it, but I have better luck stopping the mech "dead center", of the record rack, and adjusting the TMU so the sensor plunger(pin)closest to you is DEAD center, between two TMU rivets. You can also use the "meter method" I described in the guide. Ron Rich

[e093116]

Ron,

Thanks for the suggestion on the TMU alignment. I found that none of the wires were mis-connected on the frog, and besides the "normal" adjustments between the mech, frog, TMU, and record rack, I found that the reversing switch stops were misadjusted.  Took me an hour or so to figure that one out.

Also adjusted the bushings on the tone arm carriage to take out the extra movement/contact with the clamp arm frame.

I have a few minor cleanup/adjustments to finish up this weekend and this machine should be ready to load up with records once again.

Bill