Presto 6n motor speed problem

[tragwag]

very glad you fixed the problem!
This thread is, and will be very useful to anyone with a 6N.
motor and speed problems are abundant, and I can say that I've had, then not had a problem, then had the problem again while using my two different lathes consistently.

[Steve E.]

I still have to give the motor shaft a few turns before i turn it on to get the motor running but once its on, it will keep on going.

If it is any consolation, I'm hearing increasingly of top of the line Scully and Neumann lathes that have to have the turntables hand spun, to get them to start up and lock in.

[Jccc]

Thats good to hear. Im just wondering why i have to do this to the motor now.
It was working really great when i bought the cutter back in 2007 as It would start right as i would ingage the switch.

I guess this machine is just showing its age and thats just a small sign from all the years of work it has done.

So far after i did the little adjustments & maintenance its been running smooth and i will leave it at that.

[masterscott1]

Not sure what you have but some motors have a start winding and some of those use a capacitor , so the start winding and or capacitor could be bad . In either case I can help you if you need it
take care

I got a new problem now with my motor. It has nothing to do with the speed now. It has to do with it sort of not working.

It just started today For some reason when i switch the lathe motor on. It does not spin. I have to take off the platter and turn the motor shaft by hand and then it starts to spin.

I then have to turn off the motor and put the platter on so i can set the lathe up to cut. Once its spinning everything works until i turn it off then i have to repeat the same process over again.

I put oil in it where it says to add it and it still does it. I was wondering if it needs to be regreased but i do not know how to open it up.

Has anyone had this problem before?

[Stevie342000]

It is good practice with reel to reel tape machines (the kind with 3 motors - semi professional like Ferrograph or Brenell (not domestic types - which make good stops until you kick them)) to change the motor start capacitor, any suppressor capacitors across the control switches (they often short - making machines spool even in stop mode - due to leakage), as for the electronics i.e. power supplies or recording electronics - change all the electrolytics, grid blocking and look at cathode capacitors, many will be dry or leaky.

As for resistors in electronics check the anode resistors but in general check them all - replace carbon film with carbon film or metal film same wattage ratings - check schematic.

So change your motor run capacitor before you change the motor - clean the motor bearings etc and re-lube the whole thing carefully following instructions.

[tragwag]

hey JCCC and others,
I'm having a motor issue that is brought on by extended use.
Would you say you start and stop your 6N fairly often?
for example, cut for 30 min, then rest it for 1 hour?

I have a nasty flutter problem that seems to come from the motor knocking.
I just had my 33 idler re-rubberized and the speed is super consistent.

It seems that I can cut for maybe 20 minutes or so, but when the machine gets hot (I'm 'impressing' so I use a heat lamp as well)
it kicks in with the flutter. I can let it rest for about 30 min, then it will work again. But it will no doubt ruin a side each time with the flutter problem.

I'm looking into cleaning it via Angus' method here: http://lathetrolls.com/lathetrolls/forum/viewtopic.php?f=1&t=3399&hilit=6N+motor

I'll let you know if it does any good.

Thanks

[opcode66]

Could a fan be installed next to the motor to keep it cool???

[tragwag]

I tried using a fan to ventilate the motor the other day, no luck.
The fan was running all day, and there was no change at all in the behavior of the motor.
Once I'm not so busy (heh) I'll have to take it apart and clean it, per Angus' suggestions.

[tragwag]

I took the motor off the mount and tried to clean inside a bit.
I couldn't get the external housing off, but I put a q-tip inside, and got a little bit of gunk/grease out.
When I tried tightening the capstan set screw, my allen wrench kept slipping.

I'm now pretty convinced that my problem the whole time is the capstan slipping from the motor.
I can't remove the capstan at this point because the set screw is in such poor shape.

Any suggestions?

[MBL]

Well you could try and drill out the set screw. If you wind up with buggered threads, you can then tap the hole for a larger set screw. Or you can just make a new pulley.
My thoughts.
Tim
MBL

[Jccc]

hey JCCC and others,
I'm having a motor issue that is brought on by extended use.
Would you say you start and stop your 6N fairly often?
for example, cut for 30 min, then rest it for 1 hour?

I have a nasty flutter problem that seems to come from the motor knocking.
I just had my 33 idler re-rubberized and the speed is super consistent.

It seems that I can cut for maybe 20 minutes or so, but when the machine gets hot (I'm 'impressing' so I use a heat lamp as well)
it kicks in with the flutter. I can let it rest for about 30 min, then it will work again. But it will no doubt ruin a side each time with the flutter problem.

I'm looking into cleaning it via Angus' method here: http://lathetrolls.com/lathetrolls/forum/viewtopic.php?f=1&t=3399&hilit=6N+motor

I'll let you know if it does any good.

Thanks

Hello i remember i had this problem as well. It would happen when i would cut for a few minutes and then the motor would start to vibrate against the metal holder that keeps the motor in place.

I found what caused this to happen. It was that the motor shaft was too close to the rubber idle wheels. i just had to re-adjust it and mess with it until it was dialed.

Hope you got it working.

[Jccc]

So it looks like my motor is running on its last bit of life.

I was cutting some plates today and the motor started to seize up in the middle of the song.

I am currently searching for a new motor and stumbled upon this one on eBay

http://www.ebay.com/itm/Russco-KYC-41-1800-RPM-Bodine-Broadcast-Turntable-Motor-w-Start-Cap-/221215238200?pt=Vintage_Electronics_R2&hash=item338174a838

Does anyone know if this motor will work with the presto 6n?
Or if anyone knows of a better one could you point me in the right direction?

I tried using the search option on the trolls site and its giving me the run around.

[markrob]

Hi,

That looks like a great sub. You might even get lucky and find that you don't need to fabricate a mounting bracket.

Here's some good info on this type of motor and the various versions used over the years. You will see that Russco used the same older Bodine motor as found on the 6N.

http://www.russcoturntables.com/mountspower.html

Mark

[tragwag]

oh wow.
if you have good results let me know.
I would love to outfit my older 6N with a new motor.

[opcode66]

2014 DGM will be offering a wide range of motor replacements. For everything from playback turntables to semipro to full Lyric Motor replacements that work on US or Euro power.

These will be BLDC. Quartz locked. Multispeed capable. Direct Drive. High torque.

Yes, we've been busy over here....

[Jccc]

2014 DGM will be offering a wide range of motor replacements. For everything from playback turntables to semipro to full Lyric Motor replacements that work on US or Euro power.

These will be BLDC. Quartz locked. Multispeed capable. Direct Drive. High torque.

Yes, we've been busy over here....

Keep us posted to when you will have some motors for sale. Especially if you have one that will work with the presto 6n.

I am still a little un sure on the motor that i saw on ebay. As i do not know if it will fit with the old presto motor mount and if the motor spindle is the same diameter.

[opcode66]

The motor is the critical piece. The linkage can always be fabricated.

[Jccc]

Well i just purchased the russco motor off of ebay. Hopefully it it will fit the older presto 6n motor mount.

I will will post results when it arrives in the mail.

[OPP]

Hi there - long time listener, first time caller.

I've recently picked up my first lathe (Presto 6N) and the motor has disappeared somewhere in the course of time. Would anyone be able to say if this Rek-o-kut motor might be persuaded to mount and power it?

http://www.ebay.com.au/itm/REK-O-KUT-43H-base-parts-turntable-/121214463660?pt=Vintage_Electronics_R2&hash=item1c38f1eeac&_uhb=1

I await to see how you go with the Russco motor, Jccc - please keep us updated!

[Jccc]

So i received the motor from ebay the other day and it looked like i had to fabricate a motor mount for it and make a shim for the spindle.
I found some scrap metal laying around and took some measurements.








After doing that i mounted it to the existing presto mount



After doing that and making a few adjustment the motor works perfectly!