The Challenges of the AR Sugden "Connoisseur Lathe"

[Soulbear]

Hi Trolls,
Within this thread I hope to share some of my restoration (Mis?)-adventures with these classic "British Built" Lathes, of which I am lucky enough to own 3 examples :-

Connoisseur Lathe10.JPG

Connoisseur Lathe-32A.jpg

Connoisseur Lathe-41A.jpg

When I say Lucky to own these 3 examples, I must qualify this, by saying 2 of the Lathes have unfortunately been on the receiving end of "Horrendous Mistreatment" which I hope to illustrate and explain within the course of this thread. Whilst the other, having been in storage for eons, still needs lots of TLC due in part to "Flatspotting" on Components that have never turned for decades!!


Whilst not exactly in the Scully or Neumann Lathe Class, Connoisseur Lathes are what might be described as being at the "Upper End" of Semi-Pro. The Platters are driven by a Motor Capstan/Idler Wheel arrangement in the manner of some of the Presto lathes. They have a rather cleverly designed "Mechanical" Pitch Changing mechanism to alter the Lines per inch whilst cutting, all done on the Fly for loud passages. None of your computer aided Pitch Changing on these "Old Girls"!! The Cutterheads are Huge!! And whilst they are Mono Cutterheads, the specifications are quite exraordinary in comparison to the Websters, Astatic's, Audax's, RCA's, Pierre Clements, Thorens, Presto's et al. The Cutterheads are specified to have a Frequency Response up to 15,000 CPS (Cycles Per Second = Hertz or Hz for the younger reader )In No Small Part this is because rather than being a Typical "Moving Iron" Cutterhead, it is in fact a Moving Coil Head, but not an "Adapted" Loudspeaker Coil. Hope I've piqued other Trolls interest?? I shall continue this Post in due course
Regards Soulbear

[mrd]

Great stuff, look forward to following this - what's the boost button for on the top one?!

[Soulbear]

Great stuff, look forward to following this - what's the boost button for on the top one?!

Boost-4.jpeg

Boost-6.jpeg

Boost-7.jpeg

A great question!! One to which (To my eternal shame) I do not have an answer!! Try as I might, I cannot figure out what its purpose is. What I do know for sure is that it connects the capacitors into the circuit of one of the motor windings. Now here’s the rub, the Push Button is of an Over-Centre “Momemtary” Type. (Probably designed by Sugden Himself, as was the Synchronous Motor) In which case, the Motor Winding maybe sees an effect of a few milliseconds, super transient, and one I have no way of measuring. To my now ageing recollection I don’t believe I have ever encountered such a circuit before. I vaguely recall Synchronous Motor Circuits where capacitance is added or removed from one or more of the winding circuits, but such switching was done by “Latching” switches and so the Motor effectively remained in an altered “Boosted” condition until such time as these switch positions are changed again. I come from what might be best described as the “Clatter and Bang Era” of Electrical Engineering, but sadly for my research purposes, most of my own ancient Electrical Engineering Literature has disappeared into the mists of time. So over the past few days I have spent an inordinately long period of time searching on the Interweb to see if I could enlighten myself, or perhaps reacquaint myself, with some long-forgotten archaic motor control circuitry and find the answers and resolve this perplexing conundrum. Much to my frustration, and to use the parlance, I’ve drawn a blank, nilch, nimic, nada, nothing, a big fat zero!!!! Maybe the good Mr Robinson might have some knowledge of such circuits and offer to step in here?? T’would be greatly appreciated!!!
Now, as some of the more observant Trolls may have noticed, one of the Lathes has been fitted with one of these :-

Rotek KM65 Synchronous Motor.jpg

https://www.oem.co.uk/products/motors/ac-motors-and-gear-motors/motor-with-inline-gearbox-_-557130/rotek---rosync-ac-motor-_-415351

So in effect, the “Boost Button Circuitry” is now actually redundant and will not be used in one of the Lathes any event!!

Connoisseur Repairs-20.jpg

This is actually a 1500RPM Synchronous Motor, requiring a much Larger diameter motor shaft Drive Capstan to keep the Platter (Now set for single speed 45RPM Operation) instead of the 3000RPM Synchronous Sugden Motor with a smaller diameter drive shaft which gives a 33.33 RPM Platter Speed, Two further Slide-On “Shaft Sleeves” change the diameter of the shaft to give 45 and 78 RPM respectively :-




Therein lies a sad and heartbreaking tale for the reasons why I had to undertake this Motor Replacement, a tale which I will hopefully recount in my next post. Regards Soulbear

[Soulbear]

Soulbear wrote :-
"What I do know for sure is that it connects the capacitors into the circuit of one of the motor windings. Now here’s the rub, the Push Button is of an Over-Centre “Momemtary” Type. (Probably designed by Sugden Himself, as was the Synchronous Motor) In which case, the Motor Winding maybe sees an effect of a few milliseconds, super transient, and one I have no way of measuring"

WRONG WRONG WRONG!!!
Well Actually Half Wrong, Half Correct I will explain. Both of the Motor Windings have a DCR of around 340-350 Ohms. The Winding with the Phase-Shift Capacitors in Series is presumably affected as is The OTHER Winding!! These windings are BOTH connected to run in Series with a 200 Ohm Ceramic Wire-Wound Resistor. It is this 200 Ohm Resistor which is Momentarily "Shorted" by the operation of the "Boost Button" so in fact both of the windings will see a Higher (Full Mains 230V) Voltage Across them for a Few Milliseconds, instead seeing around the (Normal?? ) 150 V (-ish!) they would see across them on Switch-On, by being in Series with the Resistor.

Now, (And here I'm entering the realms of pure speculation and conjecture) I'm just a wondering if this was a design feature of our Arnold Robinson Sugden for Mid-Cut "Stops and Starts" without lifting the Cutterhead??? That perhaps is the only reason I can think of, that would possibly cause the Motor to "Bog Down" and leave it in a "Stalled State" requiring a "Boost" But then I have never read or heard of "Mid-Cut Stops and Starts" being a Technique employed in a Studio. Possibly it could have been used as a short cut Method/Technique for recording "In the Field " though???
Wiser and more Experienced Lathe Troll Heads than mine might provide more answers here??? Otherwise I remain mystified Regards Soulbear

[emidisc]

Brilliant in depth info on this British classic
Interestingly I had a tip off relating to one of your lathes that was “resting” In my home town of Bolton,
I was on the trail .....but it’s gone to a good home ...how is the new motor running & was it expensive?
Right On!

[Soulbear]

Hi Emidisc,
Ahhhh! Va Va's Club Bolton, around late 1972- early 1973-ish !!! The memories nearly came flooding back!!! (Lord above, I'm getting old Te He!!) A short lived run as a Soul Music Venue, but great fun, and great tunes as I almost remember!!

Ahem!! The Motor :- Just between me and you it cost £356.22p I'll get to the reason for the Motor Swap-Out (Very Soon I HOPE!!)

Emidisc wrote :- "Interestingly I had a tip off relating to one of your lathes that was “resting” In my home town of Bolton,
I was on the trail"

Really?? Oh I see MMMMmmm??? Curiously then, it might perhaps have been one of these Sugdens???

Archive-1 Sugden Contract-1.jpg

Archive-2 Sugden Contract-2.jpg

Bolton Studios.jpg

If it was indeed one of these Sugdens, I'm sad to say you would never have found it in Bolton, for it moved house many years ago, to closer to the Lake District, which is where I found it.

A "Circus Animal Trainer" had bought it while travelling through Bolton with the Circus many years earlier to in an attempt to make a "Carousel" for some Hamsters he was trying to Train for a Kiddies TV Show. This "Hamster Trainer" had very little engineeriing training and so therefore did not recocognise that the 78 RPM Motor Capstan Sleeve was removable. In his impatience and haste to Train the Hamsters for the TV Show, he kept operating the Sugden at 78RPM, and with the "High Speed of the Platter, the Animal Trainer unfortunately "Centrifuged" many poor Hamsters causing their early demise

As a result of this debacle, the man lost his Animal Trainers Licence and his Job, and took to becoming a Vagrant, a Hobo, which is how I happened upon him. I gave him a Lift in my car while he was "Hitch Hiking" in a Heavy rain storm pulling a small Trolley on which he had placed all his Worldly Goods including the Sugden. He told me that he had found it difficult to rid himself of what he perceived to be the cause of his misfortune, but he had now reached a point where it had become a real burden for him to keep it with him, and for a small fee, would I possibly consider taking it off his hands??
Not in the least trying to exploit the situation, but not having much cash with me, I offered to pay the man 50 pence,and give him a can of Cola and Half a Packet of Cigarettes which he Gladly Accepted!!!

Emoji-3.jpg

Soulbear

[emidisc]

Brilliant

[Soulbear]

To Continue
And now (Not in any particular order) here are just some of the issues I encountered when I received the first Sugden These are not all the issues I am attempting to deal with, the list is not exhaustive. And there is also much evidence of these Lathes needing Lots of TLC just by virtue of Deterioration of Components due to Age, Fair Wear and Tear, and Some Outright Neglect.

To continue, the Complete and Utter A**HOLES employed by the Courier Company (A POX ON THE THE HOUSE OF DPD COURIERS!! ) had seen fit to throw one of these Beautiful Pieces of Engineering around and more or less COMPLETELY WRECKED IT
The damaged was exacerbated by the Seller not following my repeated requests to Remove the Platter and Cutterhead to protect the Lathe as far as was practicable for Transit.
The Main Platter Spindle was BENT!

Connoisseur Bent Platter Spindle.jpg

The Platter Flying around by being mis-handle had "SNAPPED OFF" the Motor Output Shaft!! This Shaft Breakage was Flush with the top bearing
Following multiple wasted trips to Specialist Repair Centres and Machine Shops I finally had to accept that a Repair was beyond all these Repair Centres collective skills, and so was reluctantly persuaded and convinced that the motor was un-repairable - a Write Off

Connoisseur Motor Minus Shaft.jpg

A Part of the Casting on the Plate of the "Mechanical Pitch Changing Mechanism" was Snapped And one Part of the Overlappling "Speed Transfer" Rotors was Broken out. Probably from the Inertial Force of being Dropped

Connoisseur Repairs-9.jpg

The Cutterhead Internals had been smashed to Smithereens

Connoisseur Cutterhead Internals.jpg

Connoisseur Cutterhead Internals-1.jpg

To be Continued..... Regards Soulbear

[Soulbear]

Now having shown above ^^^^^^^ some of the damage on Lathe number 14 ( Sugden and his team rather thoughtfully stamped the lathe number on individual components during the build rather than the more conventional method used by many other manufacturers, of putting a number on a Name/Type Plate on the completed unit)

So as not to chance a repetition of this disaster, upon acquiring it, I drove to the Lake District to collect my second Sugden Lathe which is Lathe number 16. Much to the amusment of the Vendor I pulled out of my car, a small toolbox stuffed with screwdrivers, Allen Keys, tiny BA Spanners, some Tie Wraps to lock the Overhead and the like, and took great care to remove the Platter and Cutterhead before journeying back home!! So now I'm the proud owner of 1 and a half Varigroove Lathes. The first lathe still being without a Motor or Cutterhead!!

The wrecked Drive Motor, whilst being a real Pain in the *** was not an insurmountable problem. I Purchased many a number of "Alternative Synchronous Motors" to try out, from all over the UK, Bodines from the USA, Even an "Old School" Heavy Duty Synchronous Cinema Film Projector Motor!! All in an attempt to find a solution. Finally I decided that the "Most Elegant Solution" was to go with the Modern "Made in Germany" 1500 RPM Rotek. Whilst this motor has had a Cursory "Bench Test Run" and has been fitted to Lathe number 14 with a New Larger Capstan designed to only deliver a single Platter Speed of 45 RPM, it has not as yet, been run in the Lathe!!!

I then got lucky finding and Purchasing the Lathe mentioned here https://www.lathetrolls.com/viewtopic.php?f=8&t=6325

I bought it thinking that although it had no base, and the Motor was of a different type, I could still use it as a Donor for Parts for the other two Lathes and at least I now would have once more a Cutterhead for Lathe 14, and some PitchChanger and Overhead Spare Parts

But no, no, no NOO!!! Upon getting this Lathe Home, What are these????? I found to my amazement these Number Stamps on the Components inside the Lathe

Connoisseur Repairs-29.jpg

Connoisseur Repairs-27.jpg

On the Overhead I found This Cutterhead :-

Connoisseur Repairs-34.jpg

All I knew from the seller was that the Lathe Came out of the BBC Studios, But it's Lathe Number 1 coupled with Cutterhead Number 2 Two possibilties occur to me. Now I've either gone and bought either AR Sugdens Very First Prototype Lathe or or or the very First Lathe He Produced!!!! No longer going to be a Donor Project, This Historic Lathe will be now be restored in its own right. Leaves me without a Cutterhead for Lathe number 14 but Thanks to the help of another Lathe Troll I think I might have an Alternative
More about this next time Regards Soulbear

[Soulbear]

Ah well, so much for the plan to talk about the Connoisseur Alternative Cutterhead
Something Unexpected Happened which Prompted these Musings, I will elaborate in the fullness of time :-


Soulbears More Recent Observations on Ancient Recording Lathe Repair.
(With Apologies to the Laws of Messrs Sods and Murphy)

Inexpensive and Easy to Source Parts and Materials on Old Lathes are the Things that Rarely Break
Conversely, Expensive and Difficult to Acquire Parts are invariably the things that do Break
The Cost of an Item in an Old Lathe is Proportional to the Need for it, and Inversely Proportional to its Availability (Although on the Plus-Side the increased costs can be a fine natural Laxative!)

In the field of Lathe Restoration, Anything that might Possibly Go Wrong, almost Definitely Will Go Wrong!
Mother Nature Always ”Takes Sides” with the Hiddden Flaw
Mother Nature is sometimes a ***** <<<<<(Insert Your Own Expletive!)
Linear Progression or Development, when something Changes or Progresses in a Lathe Restoration straight from one stage to another is almost NEVER Achieved

In Old Lathes, if the importance of an Item Doubles, the Chances of it Failing Under Test resulting in a Complete ”Balls Up” Increase Exponentially (At the very least Quadrupling)
In Old Lathes, Awkwardness and Inaccessibility are the Hallmarks of Fragile and Delicate Components
When the Completion of a Project appears to be Close, It will Always be found that Something Else Unforeseen will cause further Delays.
If things appear to be going very well, rest assured that you have missed something really important

It will usually be found that Superficially Straightforward and Simplistic Procedures have a Multitude of Unforeseen Complexity. Bionic Eye Implants or X-ray Vision could prove a useful addition to the Restorer
Great Certainty, and Sure-Fire Solutions to demanding issues have a Bat Habit of being rewarded by Nasty Suprises
A Few Clues :-

Motor-1.jpeg

Motor-2.jpeg

More About the Connoisseurs Soon
Regards Soulbear

[Soulbear]

Hi Trolls,
I alluded to encountering a little problem with the original Sugen Motor on Lathe Number 16. It turned into a real trial!!!
Having finally Released, Cleaned and Polished the "Sleeves" which become Motor Capstans by sliding onto the very tiny Motor Output Shaft I had been doing some Speed Checks:-

Connoisseur Speed Test-3 -33.33RPM.mp4

I tested at 33.33RPM, 78 and 45RPM .

Connoisseur Speed Test-1 -45RPM.mp4

Happily, given that this machine is 61 Years Old now, the Speeds were all there or thereabouts. The Sleeves had Rusted and Siezed Solidly onto the "Storage Mounting Pins" which are on the Deckplate to the Left of the Platter. I was a little concerned that the cleaning process would reduce the diameter of the sleeves, thereby causing the Platterto run Underspeed. All the Speedchecks Showed this is not an issue as the Platter (At all Speeds) still runs a "Whisker" Fast. I have discussed this at some length with a Fellow Sugden Owner, who informed me that in all likelihood, such was the Geneius of AR Sugden, that he probably "Designed In" what might at first glance be perceived as an "Overspeed Error" notwithstanding that its a Synchronous Motor, to take account of Drag during Cutting. Indeed AR mentions slight Speed Variabilty in the the "Operating Notes" which I posted elsewhere on the Forum, but here is a reminder :-

Archive-9 Sugden Instructions-3.jpg

Suprised at how well the drive transfered from the Motor to the Plater by Using the Very Scientific "How much Index Finger Pressure does it take to Stall the Platter Test" I was adjusting the "Idler Wheel" Tensioning Spring as mentioned in the above notes, Maybe I was being a Litte bit enthusiastic, possibly ambitious, excessive even
Whilst adjusting the tensioning spring, much to my chagrin, the Motor instead of continuing to "Sweetly Hum" began making a Little noise like something was "Binding" within a few seconds the Motor came to a "Dead Stop" I quickly turned it off and then tried to spin the Rotor by hand, It was Locked Solid!!!

My assumption was that a small piece of dirt or something had found its way into to Open Motor End Plate. On taking out the Motor and Pulling it apart I could see the Slightest Hint of a Rub Mark on the Stator but no dirt inside the motor to speak of. But the Motor is so finely engineered there is "Bugger All" of an Air Gap Twixt the Rotor and the Stator. To make a bad situation worse the Rotor Is Centred by the End Cap Bearings and Bushes, The Stator Yoke is Centered in the Motor Frame by 3 Pairs of 6BA Grubscrews spaced 120 Degrees apart around the Motor Frame.

Seeing where I though the Slight Rubmark to be was Located on the Stator, I thought I'd "Back Off" the Pair of 6BA Grubscrews Closest to this spot and "Feed In" the Grubscrews Opposite. This off course meant first Loosening all the Locknuts Holding the Grubscrews tight into the Motor Frame.

MASSIVE ERROR!!

SyncMotor-9.jpeg

Not Exagerating!! It took me a week to get the thing SET UP Properly Again!!! I would think things were OK, The Motor Spinning Freely by Hand On the Bench, only to find that when refitted to lathe and Powered Up I could Hear the Slightest of Rubbing Noises. Running at 3000RPm It would not have taken Many seconds running for the Rotor/Stator Rubbing together to cause Thermal Expansion and another Lock Up. Even after it felt perfect on the bench, refitting the Motor proved to be a challenge, the Motor is Mounted by 3x 6BA Countersunk Screws into the Motor Output End Plate. I took Out some Rotor End to End "Float/Slop" by Adjusting the Bush where the rotor Needle Point Bearing Sits, That Cause the Rotor to Lock Up BEFORE POWERING UP!!! when simply Mounting the Motor Back into the Lathe
So Trolls, if you get yourself a Lovely Sugden, MY ADVICE IS THIS
If the Motor is Running Sweetly
DO NOT BUGGER ABOUT WITH THE IDLER WHEEL TENSIONER!!!!!
TE HE!
More Next Time Best Regards Soulbear

[Soulbear]

Hi Trolls,
EXCLUSIVE TO LATHE TROLLS!!
POSSIBLY A WORLD FIRST!!!
You May recall I mentioned that I had fitted the Rotek Motor to Lathe Number 14 because of the damage caused when in transit to me?? Only having run the Motor on the Bench!! I also mentioned that because the New Rotek Runs at 1500 RPM I had to fit a larger Capstan to Drive the Idler. Well Now I've run the Motor in the Lathe and it is SWEET SWEET SWEET!!
Not ONLY THAT!! Heres the Exclusive;:-
The Worlds First BELT DRIVEN CONNOISSEUR????????

Connoisseur Belt Drive Speed Test-1 -45RPM.mp4

Regards
Soulbear

[Soulbear]

Hi Trolls,
EXCLUSIVE TO LATHE TROLLS!!
POSSIBLY A WORLD FIRST!!!
You May recall I mentioned that I had fitted the Rotek Motor to Lathe Number 14 because of the damage caused when in transit to me?? Only having run the Motor on the Bench!! I also mentioned that because the New Rotek Runs at 1500 RPM I had to fit a larger Capstan to Drive the Idler. Well Now I've run the Motor in the Lathe and it is SWEET SWEET SWEET!!
Not ONLY THAT!! Heres the Exclusive;:-
The Worlds First BELT DRIVEN CONNOISSEUR????????

I've spent a little more time conducting "Speed Tests" and am happy that the Speed is close enough, but was somewhat perplexed by the "Strobe" indicating a "Slight Overspeed" Given that d1 n1= d2 n2 where d1 = Rotek Motor Driving Pulley Diameter = 0.360inch @ Speed (n1) = 1500 RPM and d2 (Platter Diameter = 12,000 (12" Dead) This should have given me n2 = 45RPM Platter Speed!! Exactly!!!
These measurements were checked and checked again, every which way, and not by using some Rusty Old Tape Measure, or a Piece of String, but by Using Both Large Digital Read-Out Verniers AND Manual Micrometers.

To measure the Platter involved making a Road Trip with the Platter to visit the Facilities of a Precision Toolmaking Friend, who has more Measuring Equiment that you can shake a stick at!! Other than a 0-6" Digital Vernier and a 0-1" Micrometer, I simply do not have these Measurement "Toys"
I can only put this down to Perhaps "Thermal Expansion/Contraction" Issues coupled with some Slight Variablity with the Mains Frequency.
The UK mains frequency is nominally 50Hz, and the National Grid is obliged by its licence commitments to control the frequency within ±1% of 50Hz so it can fluctuate between 49.5Hz to 50.5Hz. Without dropping a Frequency Meter onto my Household Supply, I can confirm that there is Variabilty in the Indicated Speed which changes with the "Time of Day" when Measurments are made!! How heavily the Grid is Loaded etc. However Trolls, I can live with this Speed being slightly "OFF".

What I could not live with was The "Dogs Dinner" of the Ill-fitting Aluminium Sleeve I made, which turns the Capstan into a Pulley "Propper" I'd ruined my "One and Only" 23/64" Sharp Drill Bit ,Trying to Centre Drill a "Stainless Steel" Collar for the Capstan, I failed in this endeavour, because the Stainless was simply too hard to Drill, and I burned up the Cutting Edge of the Drill Bit So I ended up using the "Quite Close but not Exact" Aluminium Sleeve from a Pulley I managed to cut down.
I was Happy that I managed to make the Sugden work as a "Belt Driven Lathe" but wasn't happy with the "Finished Look"

Neccesity is the mother of Invention or so they say, and while hunting around for my "Martek Drill Bit Sharpener" I happened on some Nylon "Stand Off Spacers"
Result!!! The "Blunt" 23/64" Drill Bit was up to the Challenge of Centre Drilling "Soft Nylon" and is Now Fitted "Snugly" to the Captan with a 3mm Grub Screw. Aesthetically Much Better

Connoisseur Belt Drive Speed Test-2 -45RPM.mp4

Regards Soulbear

[emorritt]

Nice work! I modded my Presto 6N with a stepper motor from Anaheim Automation and drive belt because the idler mechanism was just too noisy. Dead silent grooves after that.

[Soulbear]

Nice work! I modded my Presto 6N with a stepper motor from Anaheim Automation and drive belt because the idler mechanism was just too noisy. Dead silent grooves after that.

Well now Eric, you have got me intrigued
Though it is some time since I was reading around this, I studiously steered away from using a "Stepper Motor" being detered somewhat by reading quite a lot of "Negativity" regarding "Smoothness" and "Noise Transfer" Maybe I'm confusing things, and it was in relation to using a "Stepper Motor" for driving a Overhead Leadscrew that caused problems, now that would make sense in terms of "Noise Transfer"

My instincts tell me that the Steppers might be eminently suitable for a Platter Drive after all!! Given the Inertia and Weight of the "Reasonably Sized Platters" found on the Older Lathes, in Comparison say, to the "Mickey Mouse" Platters on the "Modern Turntables" used for Lathe Drives (Yes even the Technics SP10's (Provocative??) !!) Not really!! more akin to Comparing a V8 Muscle Car to a Highly Strung Lotus or Ferrari!!! Intuitively I feel that with a Motor with a High Step Rate/Rev any Older Platter/Belt Drive Combination would easily smooth out and eliminate any problems??

Compared to the cost of the Rotek Motor, I guess it is "Far Less Expensive" but loooking at the Anaheim Automation site still not that cheap!! Can you give me a clue which Motor did you choose please?? there are so many to pick from!! Nema 17 Nema23 other?? TE HE Tell me if you will, how or with what you managed to determine and "Set" the final Platter Speed"?? A Strobe Disc, Counting Step Pulses or some other method?? As I mentioned, I'm really most intrigued

I would maybe like to give this a shot on some of my "Other Rebuilds" I have one of these I could use around somewhere :-

https://www.ebay.co.uk/itm/TB6600-1-Axis-4A-42-57-86-Stepper-Motor-Driver-Controller-40V-Micro-Step-CNC-UK/313123621764?hash=item48e79f4b84:g:Z2gAAOSwvaBcw0Z9

and I also have some of the "Smaller Nema 17 Size Motors, though I would Probably need a Motor with a litttle more "Grunt" methinks
Oh well, maybe I'll have to look again at this, another thing to add on the "To Do List" Regards Soulbear

[jjwharris]

Check out my JE-98D topic. I went with a big heavy steel platter driven via belt with an integrated servo and square wave generator. The platter and pulley is terribly machined but the big heavy platter seems to smooth everything out. - Bryan has done something similar with his Fairchild.

[emorritt]

It was one of these:

https://www.anaheimautomation.com/marketing/stepper/standard.php

but I don't recall which one. I bought a power supply for it from somewhere like https://skycraftsurplus.com/power-supplies.html?cat=469 don't recall if it was 12 or 24VDC, but they need a stable power supply and then followed the schematic that came with the motor to create a potentiometer speed control. Would use a strobe to set the speed then record once running. I was going to create a fixed resistor speed switch for 33-45-78 but never got around to it before selling the machine. Anaheim has an overwhelming choice now; this was back in 2007-2008. Speed was stable and I used a large O-ring for the drive belt from https://www.theoringstore.com/store/index.php?main_page=page_2 in about 17 inch diameter to accommodate the turntable and the off-board drive motor. Ended up sort of like a big Universal machine, but without idler noise.

[nikc]

Hi there. I look into this too as a bit fed up with idler wheel noise on my MSS. I have tried tensioning springs and trying to get the wheel smoother but you can hear the rumble on the vinyl. I have a spoke at 4000 hz on my recordings too which I was wondering was from the idler too although it seems a bit high.

Nik

[nikc]

PS The spike at 4000 hz is probably something else but disregarding that I can hear a low rumble on a silent groove

[emorritt]

Yes, the older style idler or rim driven turntables provided a good amount of noise. Have you checked the turntable bearing? It's at the bottom of the well where the TT shaft sits. Those wear out and need replacement when they become scored, which makes noise as well.