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Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Tue Sep 03, 2013 3:58 pm
by chrisjoonior
DoghouseRiley wrote:I'm not sure if I understand all you've said.
But here's my two penn'oth.
I've a couple of Rock-Olas, but they only play 45s, (one plays small hole records, the other large hole ones) Neither has the facility for 33 1/3rd, nor do they have a working "intermix" mechanism. So I'm a bit in the dark. But I've noticed that the motor shaft is "stepped."
I thought the dropping of the three pins on those turntables with the facility, activated the mechanism which moved the jockey wheel from one position on the motor spindle, to the other.
If it will no longer play 45s and you've not done much to it other than lift the turntable on and off, it could be as simple as this. The grommets as have been mentioned can be an issue. If the motor drops slightly because of failing grommets, it won't now turn on the jockey wheel in the 45rpm part of the motor spindle and is permanently rubbing on the 33 1/3rd section at the top.
Incidentally with hardened or failed grommets you may get a background noise caused by the motor vibrations during play.
The grommets on the motor mounts are definitely corroded, thankfully that's a pretty easy solution for me. I have a number of rubberized pieces I can cut to fit to restore that aspect of the assembly, but I'm not sure that's a part of my problem (yet!). I can easily actuate the 45 RPM and 33-1/3rd RPM operation with what everyone is calling the "Sensor Lever Spring". I wouldn't be surprised if replacing the grommets would help out with some over the LF rumble the turntable exhibits, but the whole unit still sounds surprisingly decent, considering its age.
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Tue Sep 03, 2013 5:09 pm
by DoghouseRiley
chrisjoonior wrote:DoghouseRiley wrote:I'm not sure if I understand all you've said.
But here's my two penn'oth.
I've a couple of Rock-Olas, but they only play 45s, (one plays small hole records, the other large hole ones) Neither has the facility for 33 1/3rd, nor do they have a working "intermix" mechanism. So I'm a bit in the dark. But I've noticed that the motor shaft is "stepped."
I thought the dropping of the three pins on those turntables with the facility, activated the mechanism which moved the jockey wheel from one position on the motor spindle, to the other.
If it will no longer play 45s and you've not done much to it other than lift the turntable on and off, it could be as simple as this. The grommets as have been mentioned can be an issue. If the motor drops slightly because of failing grommets, it won't now turn on the jockey wheel in the 45rpm part of the motor spindle and is permanently rubbing on the 33 1/3rd section at the top.
Incidentally with hardened or failed grommets you may get a background noise caused by the motor vibrations during play.
The grommets on the motor mounts are definitely corroded, thankfully that's a pretty easy solution for me. I have a number of rubberized pieces I can cut to fit to restore that aspect of the assembly, but I'm not sure that's a part of my problem (yet!). I can easily actuate the 45 RPM and 33-1/3rd RPM operation with what everyone is calling the "Sensor Lever Spring". I wouldn't be surprised if replacing the grommets would help out with some over the LF rumble the turntable exhibits, but the whole unit still sounds surprisingly decent, considering its age.
You'd be better off buying the proper replacement grommets, they are, as we say over here, "Cheap as chips!"
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Tue Sep 03, 2013 5:59 pm
by Ron Rich
Chris,
Unless you have extremely good luck, IMHO, you will wind up spending more time and trouble using "homemade" grommets, then it's worth--I have been in "emergency situations" where the phono was in commercial use, and tried to rig it for one night--most of the time I could make something work, but never correctly, until I came back with the proper,"white" grommets. These ARE available--check above for list of suppliers--
Ron Rich
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Tue Sep 03, 2013 6:03 pm
by chrisjoonior
Cool, any advice on the bearings? Am I on the right track with that?
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Tue Sep 03, 2013 6:29 pm
by Las Vegas Jukebox
DoghouseRiley, your absolutely correct in your understanding. When I bought my 425 someone had put an extra washer under the idler wheel causing it to permanently play at 33-1/3, but everything else (i.e. the large hole sensing pins) worked okay. I think it it important that Chris gets the pins working correctly before looking for other faults which may or may not be there. Chris wants to use his jukebox with both small and large hole records, both running at 45-rpm, so the pins must work. If he only needed one or the other then the pins wouldn't be an issue, he could just fix them "up" or "down" and make sure that the idler wheel was in the correct position on the drive shaft.
Chris - yes, it is normal for the underside of the turntable not to be shown in the service manual or parts catalog. I don't know why, perhaps Rock-Ola never saw any serviceable parts there and expected the whole turntable to be replaced if there was a problem.
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Thu Sep 05, 2013 12:26 am
by Rocka Rolla
I was looking through some earlier Rockola parts catalogs today, and they actually show the ball bearings. The Rockola # is ST-1214 and the size is .156". If you need a pic of the parts explosion, send me a PM. Incidentally, two different parts catalogs show two different assy. numbers for the turntable. The sensor and pin assy. have a different part number (-A suffix on one), otherwise every other part is the same.
Jim
Re: Rock-ola 452 Small Hole Issues (with video!)
Posted: Thu Sep 05, 2013 12:30 am
by Rocka Rolla
Just looked in the 453 / 454 parts catalog, and the ball bearings are the same part # and size FWIW.
Jim