How to lubricate motor, etc in Turntables.

[mbhangui]

Today I pulled out one of my turntables Akai AP 55. It does have a functional dust cover. But to my display I find that lot of dust somehow went inside. I have removed all traces of dust. But since I opened it up, i thought of lubricating various parts where metal rub against metal. All done except for the Direct Drive motor. Couldn't figure out where to put the oil. I generally use Johnson's baby oil as I find it has never harmed plastic, rubber, etc. I guess it is some kind of silicon oil.

I also cannot download the service manual from vinyl engine. If anyone can download it for me, I will be grateful. You can email it to mbhangui at gmail.com

EDIT: I managed to get the service manual but couldn't find anything about lubriciation.

View from the top side with the platter removed.



View from the bottom with cover removed. One can see the RCA cable soldered to a PCB. I'm thinking of removing this cable and put good quality RCA connectors. But I think in those days the capacitance of the cable played a part in getting the correct frequency response, but I'm not sure. Let me know if this shouldn't be attempted.



This looks like the control and driver circuit for the motor. All look fine. There are 3 fuses on the board.



This is a closeup of the motor. I did not dare to open it. The bulge in the center looks like a bearing inside. Couldn't figure out where to lube the motor.
Motor is labelled DDM 6C. Looks like DDM stands for Direct Drive motor.



Full view from the bottom

 

[manek]

Today I pulled out one of my turntables Akai AP 55. It does have a functional dust cover. But to my display I find that lot of dust somehow went inside. I have removed all traces of dust. But since I opened it up, i thought of lubricating various parts where metal rub against metal. All done except for the Direct Drive motor. Couldn't figure out where to put the oil. I generally use Johnson's baby oil as I find it has never harmed plastic, rubber, etc. I guess it is some kind of silicon oil.

I also cannot download the service manual from vinyl engine. If anyone can download it for me, I will be grateful. You can email it to mbhangui at gmail.com

EDIT: I managed to get the service manual but couldn't find anything about lubriciation.

View from the top side with the platter removed.

View attachment 72249

View from the bottom with cover removed. One can see the RCA cable soldered to a PCB. I'm thinking of removing this cable and put good quality RCA connectors. But I think in those days the capacitance of the cable played a part in getting the correct frequency response, but I'm not sure. Let me know if this shouldn't be attempted.

View attachment 72250

This looks like the control and driver circuit for the motor. All look fine. There are 3 fuses on the board.

View attachment 72251

This is a closeup of the motor. I did not dare to open it. The bulge in the center looks like a bearing inside. Couldn't figure out where to lube the motor.
Motor is labelled DDM 6C. Looks like DDM stands for Direct Drive motor.

View attachment 72252

Full view from the bottom
View attachment 72253

Perhaps its a sealed bearing so one need not lubricate it ?

 

[arj]

I guess this is a DC motor ? i have taken apart the lenco motor and greased it as lenco heaven had a thread around it. The Garrard has a hole to grease it so did not have to open it.

Best option is perhaps dropping a drop or 2 of oil down the spindle ?

 

[mbhangui]

I guess this is a DC motor ? i have taken apart the lenco motor and greased it as lenco heaven had a thread around it. The Garrard has a hole to grease it so did not have to open it.

Best option is perhaps dropping a drop or 2 of oil down the spindle ?

I took a look at the spindle. Beneath the spindle is a large flat disk. So if I drop oil, it will just accumulate on the disk. I did a google search on DDM 6C and I found this picture. From the picture it is clear that if I remove 4 screws at the back the entire motor will come out. I can then put few drops of oil from a dispenser with a long thin spout. The thing about this motor is that the spindle is not touching anything. It goes through a hole which is much larger, in fact larger than the white gear. If you see the first photo that I posted it will be clear. It is the small gear and another larger gear that is holding this thing in place. So there are only two contact points
The top contact point is where the gear meshes together
The bottom contact point is a bearing on which this whole contraption fits. So I need to oil the bottom bearing and apply silicon grease on the gear. I find the existing grease on the teeth have totally dried up.

Brilliant arrangement I would say because the Japs have reduced the friction to only at the point of contact of the gears and the bottom bearing.

 

[Hiten]

hi,
I checked if any DD motor pictures on the net. I found this.



The last picture you posted shows the spindle is attached to a disc with magnet on bottom. if you pull the assembly of spindle+disk+magnet will be out of the bush bearing. The bottom does not look sealed so one or two drops of sewing machine oil is enough, otherwise it will seep out. first carefull clean the shaft bush of any dirt or old lubricant. Usually IPA works. Be extremely careful while taking out the spindle assembly as usually thin copper motor windings are below it.
I repeat be exteremely careful.
regards

 

[Subbu68]

I would go in for silicone grease but choose one for motor drives. It will last longer than oils that can dry out. Also would not make the cogs (those nylon ones) sticky.

 

[mbhangui]

hi,
I checked if any DD motor pictures on the net. I found this.

View attachment 72272

The last picture you posted shows the spindle is attached to a disc with magnet on bottom. if you pull the assembly of spindle+disk+magnet will be out of the bush bearing. The bottom does not look sealed so one or two drops of sewing machine oil is enough, otherwise it will seep out. first carefull clean the shaft bush of any dirt or old lubricant. Usually IPA works. Be extremely careful while taking out the spindle assembly as usually thin copper motor windings are below it.
I repeat be exteremely careful.
regards

This was helpful and confirms what I was suspecting that it is the bottom bearing that I have to reach. Good tip about the IPA.

 

[jls001]

@mbhangui : service manual can be downloaded from this link.

akai ap55 service manual pdf - Google Suche

 

[mbhangui]

@mbhangui : service manual can be downloaded from this link.

akai ap55 service manual pdf - Google Suche

Thanks. One kind fm has already emailed me the PDF.