Question for Presto 6N operators regarding overhead set-up

[SONARC]

Hi there -

Recently, I took an unanticipated two-month covid break from working in my little lathe studio. Once I was back on my feet, I thought it would be a good idea to start fresh with everything, rather than just pick up where I had left off.

This included cleaning up a few parts, and re-calibrating everything from scratch, which is something I do fairly routinely between projects, but this time I had been out of touch for longer than usual, and apparently I was a bit more precise in setting everything back up this time. Even though that sounds like a good thing, it actually called out an issue I didn’t know existed.

The person I purchased my 6N from had done a terrific job of refurbishing it - complete overhaul of the motor, wiring, etc, but they did tell me there *may* be an issue with the part referred to in the manual as an Overhead Adjusting Ring - or, what some folks in these parts refer to as a “collar”.

adj ring [noted IMG_2231].jpg

The original part was missing, and my unit came with two options for the adjusting ring -

one, a split shaft collar that raised the Swiveling Elbow Joint shaft too high - almost double what I presume the height of the original might have been

shaft raised in collar [noted IMG_2224].jpg

shaft collar measurement [IMG_2227].JPG

and a makeshift “ring” cut from a piece of wood by the previous owner, that seemed to be *nearly* the correct height, with an additional shim I borrowed from an old faucet fixture - not pretty, but it does the job

shaft raised in wood ring [noted IMG_2226]222.jpg

wood ring measurement [IMG_2229].JPG

I'm curious what other Presto 6N operators are using for the Overhead Adjusting Ring on their units, and if it ends up being a Shaft Collar, where replacements might be obtained. Believe me when I say I’ve talked to a *lot* of parts manufacturers who make shaft collars in every size conceivable, except for the size my 6N would seem to require. Likewise, I’ve struck out with a number of hardware stores, salvage outlets, and estate sales.

I'm equally curious what the measurements are for that part on other people's 6Ns, as well as the thickness of the pad others are using under the Flange (what some folks refer to as a "foot") that fits over the Turntable Shaft.

flange [noted IMG_2236].jpg

On my 6N, with the wood ring supporting the Elbow Joint, and a .0650” piece of neoprene as a pad under the flange, everything is perfectly level.

level [IMG_2239].JPG

The issue in this case, is that in order to keep the flange completely flat on the disc, as well as keeping the entire overhead level (to avoid creating grooves that are more shallow on one end or the other), I seem to be having a devil of a time getting the carriage assembly set back up so that I can have the clearance I need between the stylus and the surface of the disc.

Strangely enough, it was set up perfectly for the last run of singles I did before I came down with covid. Once I got back in the lab and started to get back to work, something [?] went out of position within a few tests - I was no longer getting silent lead-in / lead-out grooves, and the audio itself began to change ever so slightly with each test.

To the best of my understanding, the fault would have to be in either the carriage, or the overhead assembly. Even though the flange is perfectly flat, the Overhead Adjusting Ring could certainly stand some improvement.

I’ve assembled and set up the carriage many times in the past several years, but something seems to have changed this time, and I need to get more clearance between the stylus and the disc. I’ve entertained the notion that those pesky little pivot screws may be a contributing factor - and may possibly not be holding the carriage in securely any more - but that’s another part I can’t seem to locate replacements for.

That leaves me still searching for the perfect overhead ring, but whatever I use to the support the overhead can’t be *too* high, or the pad under the flange would have to be thicker as well, and would still need to fit snugly over the turntable shaft.

Sorry about all the words, but I reckon too much information is always better than not enough.

Thanks for any suggestions anyone may have!

[apoklis]

the collor is .25 thick and had two set screws 6/32 at 90 degrees . I m having two machined at a local mechine shop .Well waiting for a estamate for the machinist. Ill pm you a price for one this week, if you want.
But in the meantime , because your is a real 6n and not a frank n lathe use the setscrew below it to hold the shaft hight. Or am i missing something.

[apoklis]

picture

[SONARC]

If you're having extra collars machined, I would definitely be interested in one - thanks for the offer.

I've actually thought about doing what what you suggested and holding the shaft higher with that setscrew / bolt, but that would mean I'd need to raise the flange higher as well, in order to keep my grooves the same depth from start to finish. There's not much much room to play with where the flange height is concerned, because it would only be flush with the turntable shaft for about 1/8". Maybe I'm wrong about that?

the collor is .25 thick and had two set screws 6/32 at 90 degrees . I m having two machined at a local mechine shop .Well waiting for a estamate for the machinist. Ill pm you a price for one this week, if you want.
But in the meantime , because your is a real 6n and not a frank n lathe use the setscrew below it to hold the shaft hight. Or am i missing something.

[apoklis]

if your taking that far , try adjusting the foot hight by losing the drive grear .It only buy you a little but could help if its that tight.But im do know if that your problem. When you look under a scope are the grooves the same width at the start as the inter loop? Ill talk to machist on monday and pm you.

[apoklis]

the top flange sit up in the air .I just keeps the collor form going to far up.

[apoklis]

The more i think about,it and the above description, im thinking it just a stylist . Are you cut or embossing ? is it a cone shape stylist? If so try spinning it 120 degrees .Mike,who sells them, says 180, but ive had luck at 120 and three turns out of them before there done.

[SONARC]

Hey there apoklis - Thanks for the suggestions - and photos! That will give me a couple of new things to try.
Amazingly, I reckon, I've been able to make some great sounding records all this time in spite of the minor caveats I mentioned that the unit came with.
But this time something definitely shifted, and it's been a real bear trying to work thorough it - especially since I was in the middle of a few runs at the time.
I can always find some kind of workaround, but it would be great to get this back to 100% for sure.
Hey, I was curious about the first photo you posted - the part on the right looks like the shaft from the overhead - I've just never seen it completely removed from the overhead elbow joint before. And is that an original adjusting ring on it? Also, the part on the left appears to be a bit larger - I'm not exactly sure what that one is, I guess.

[apoklis]

The ring is an original adjusting ring . the shaft is an original the brass thing is something i have made and use on frank n lathes to mount to a base . But because it had the screw hole on the side ,I just thougt it would be a good example.

[SONARC]

At the moment, I'm just embossing. I'm mainly using the embossing cones Mike sells, and for testing purposes, I've tried old stock, new stock, as well as some backward sapphires that I've had great success with, even old re-sharpened victrola needles, ala Peter King. No mater what though, the current issue I mentioned seems to come right down to the set-up, which is why I'm looking hard at the carriage and the overhead assembly.

The more i think about,it and the above description, im thinking it just a stylist . Are you cut or embossing ? is it a cone shape stylist? If so try spinning it 120 degrees .Mike,who sells them, says 180, but ive had luck at 120 and three turns out of them before there done.

[apoklis]

brass.jpeg

[andyburnout]

I had a similar issue the other week where my grooves were slowly fading away into the centre. With my 6n if I manage to get something to play all the way through I don’t try to touch too much I feel like soon as a change too much it will take me days to get back to that point. It’s hard to explain to someone the excitement when everything works out.

[sameal]

In the meantime, I wonder if you could belt sand the shaft collar you do have down enough to work.

[piaptk]

I had a similar issue the other week where my grooves were slowly fading away into the centre. With my 6n if I manage to get something to play all the way through I don’t try to touch too much I feel like soon as a change too much it will take me days to get back to that point. It’s hard to explain to someone the excitement when everything works out.

If your grooves disappear towards the center, then that means the left side of your overhead is too low, so the stylus is slowly going up hill...make sure your center foot is totally flat on the disc...