Belt Drive Turntable Shut-off Mechanism

I had to repost this video because I forgot one video sequence and it is not possible to keep the old url. The video is now 2 minutes longer.
There exist variations of this mechanism (velocity trip).
The big white wheel with the teeth is the cam gear; this helps convert the rotational motion of the platter into linear motion. Therefore the label "cam," Here the cam gear moves a lever.
The trip mechanism is activated when the tone arm moves faster (this is the "velocity" part) at last groove of the record. The plastic trip linkage, which is connected to the tone arm, moves the metal trip levers slowly toward the platter gear while the record is playing. There is a singe tooth above the plastic platter gear. Both trip levers work together and are on the same pivot.; at the very end of the record, the lever closest to the tooth catches the tooth and the gears are activated. The movement of the cam gear forces the pin (itself part of a slide lever), which rides in a groove, toward the reset position--moving the tonearm toward the start position too. The motor shuts off because the switch opens.

[@VinylTV33]

Very well explained. I never fully understood how this worked.

[@OldSchoolElectronics]

Thanks, for your kind words. I have just subscribed to your channel, which was unknown to me, probably since I generally only watch the videos, as far as audio/electronics is concerned, of my subscribers.

[@patrickoconnell3896]

Interesting piece of engineering. Always something new to learn. Thanks for the video, always interesting.

[@OldSchoolElectronics]

Thanks for watching and your comment!

[@krish8216]

Well explained about the auto return mechanism in detail. Thanks

[@OldSchoolElectronics]

Thanks for your kind words.

[@ilybee3421]

Hi, thank you for this informative video! I have a player that has this mechanism. It is currently returning too early when playing 45s. Do you know why this happens?

[@markantonyrodriguez7998]

Hi , your video was so good. Actually i have a silver brand Turntable comes with the same mechanism. I removed the cam gear ,but timing changed . Now the tome arm is raised when it plays for 10 seconds. Can you pls mention the model of the turntable, which is demonstrated.Thanks.

[@alcameron6071]

Now, that was very interesting. I have a Kenwood KD-38R turntable which has the automatic return feature. I just got it up and running after sitting for some time. I noticed when the arm reaches the end of the record and starts returning to the arm post, about 2/3 of the way it makes a groaning sound. possibly the black arm is rubbing and making that groaning sound from lack of lubrication? I'm guessing at this point because I haven't turned over the turn table yet. Another thing I noticed, the belt seems to be rather loose on the spindle from the motor. I have ordered a new belt because I'm sure it's probably the same one that came with the turntable. I do from time to time, notice a slight wow and flutter and am pretty sure the belt is probably what is causing it. when I get the new belt, I'll be inspecting underneath to find the cause of the groaning sound. Thanks for the great video.

[@OldSchoolElectronics]

Thanks for watching and your comments! Belt needs changing for sure. Might be lubrication needed--lightly. Hard to do a remote-diagnosis: from here. Good luck!

[@Hi-Tech-Ray]

who makes this mechanism, I have the HP5 on an LXI series!

[@michaellalwani9561]

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[@OldSchoolElectronics]

Hollar at me when you reach the next galaxy.