Presto 6n Speed issues..

[JayDC]

Ok, I even whipped out the manual for this one, and spent hours adjusting everything, still can't seem to get the strobo to float correctly.. I have gotten it for a little while at a time, but once the lathe sits for more then an hour I have to readjust the whole thing, it's driving me nuts.. The idlers are newish, terry did them within the past 2 years.. The only things i can think of are:

A). The rubber on the idlers are changing size due to the temperature dropping and warming up in the basement.

B). The frequency of the line voltage is not a steady 60hz, and is causing the motor to spin at slightly different speeds.

Did i miss anything? Is there a way to solve these issues, if they are in fact the issues.

I cut music for the first time in 2 years last night, and it sounded great, just not exactly at 45rpm, and its changing the pitch of the recording slightly.. Enough to annoy me..

My newly designed rear vac system is totally AWESOME though, and cost about $4..

[petermontg]

you could have a dint in your idler that you cant see. you might be able to feel it though. if you rub your finger along it.

or your idler is not making full contact with the platter.

have you a test disc to run on the platter

[JayDC]

Yeah I'm using a strobo test disc on the platter to calibrate the speed, just cant seem to get it steady, and once i do, it changes again. I'll set it all up, calibrate it, and have it locked.. come back an hour later to check it again, and have to readjust the whole thing..

[petermontg]

could be a motor problem so

try this test before you start spending cash on repair

http://www.elusivedisc.com/prodinfo.asp?number=APLPTES

[petermontg]

for some reason that link wont work ill pm it

[JayDC]

How would that disc help my speed issues? And how am i supposed to do the tests if the turntable has no playback tonearm? I think this disc is more for setting up audiophile playback turntables, not really cutting equipment..

[petermontg]

ok its not going to help you so if you have no playback arm.

id take it out of your basement first and put it in a room with a constant heat and reset if you still have same problem its motor.

but rub your finger along your idler wheel

[monkey1553]

Jay, have you tried just letting the thing run for awhile? I have an old rek-o-kut idler turntable that is very similar in design to the drive on the 6n and the thing runs slow for two to three minutes until it gets up to proper speed. I believe this is due to old oil in the lower motor bearing that has gummed up after sitting over time. You said you haven't used yours for awhile so I'm wondering if that might be the issue with yours.

~Michael

[JayDC]

mmm.. interesting possibility.. I'm going to run it for an hour tonight, and see if that improves the speed issue i'm having.. Another friend of mine also said that maybe the motor's brushes are getting too old.. What type of shop can restore these motors?..

[monkey1553]

Did you have any luck? Not sure who to track down to get one repaired. I'm sure other trolls can can chime in with some recommendations.

My rek-o-kut motor has a tube for lubricating that bottom bearing. You may check your presto motor for something similar. It runs much better after I shot a bunch of wd-40 into that tube and then finally some light oil. It still runs slow for a bit if I don't use the turntable for long periods of time but it is way better than it was.

~Michael

mmm.. interesting possibility.. I'm going to run it for an hour tonight, and see if that improves the speed issue i'm having.. Another friend of mine also said that maybe the motor's brushes are getting too old.. What type of shop can restore these motors?..

[JayDC]

I re-lubricated the motor, and I'm letting it drive the platter for warm up, its getting close but still drifts a little. I start to realize that the are in fact 3 adjustment areas that will effect the presto speed.. The motor height adjustments, the motor mount adjustments, and speed selection leaver. So I think its just going to take some time to find the correct mixture of all 3 adjustment to lock the correct speed.

Made some test cuts the other night with the slight drift in the speed. To me there are no audible differences, and there doesn't seem to be any wow and flutter. I will cut another disc soon, and try beat matching them, to see if there are significant amounts of wow on the disc.

Would it be wrong to be okay with cutting disc's at 44.8 rpm?

[JayDC]

Okay.. I found that the speed is set perfectly if the overhead mechanism is not placed on the turntable.

Not sure what to do, everything seems lubricated well.

[monkey1553]

Hmmm. You've already messed with the idler adjustment and lubed everything. Is it just barely off with the overhead on the table then?

Okay.. I found that the speed is set perfectly if the overhead mechanism is not placed on the turntable.

Not sure what to do, everything seems lubricated well.

[JayDC]

exactly.. the drag from the overhead is slowing the platter, and for some reason i can not nail the speed with the overhead on the platter at all. When there is no overhead on the platter the speed is perfect.. Even if i adjust without the overhead on the platter to get the speed faster to compensate for the drag of the overhead, it still slows down as soon as i place the overhead on the platter.. very frustrating..

[JayDC]

I solved this issue.. it was all about getting the motor height adjustment correct..

[monkey1553]

Nice! Glad to hear you got it!

I solved this issue.. it was all about getting the motor height adjustment correct..