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My first idler TT and restoration. Building a plinth, damping, tonearm board etc. starting with mint

Tonight's task is boiling the tar out of the spindle wells. I put a mix of Diesel and 10w30 in a bean can, then placed that inside a coffee can in case of any mishaps, then placed the whole rig on the wood stove, it's simmering nicely, dinner's at 8.

Cheers

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Okay boys tonight is the night I re-oil the oil-lite bushings heating up as I did when I was cleaning them last night but this time with fresh oil. I would like to know if you can in the next three hours or so what is the preferred oil to use in the spindle well? I have in stock for my machinery, hydraulic 32 and 46 weight as well as a gallon of synthetic industrial oil straight 30 weight from when I was maintaining surfacemount machines at an electronics manufacturing place 15 years ago. I also have the usual assortment of automotive engine oils 10 W 30, 15 W 40, ATF etc. etc.

Your guidance is most appreciated. Thank you

Paul
 
Thanks Andy, I ended up using ISO 46 hydraulic oil, heated it on the wood stove then let it cool in the can of oil overnight, it should be good now. When the table is going back together I will fill the well with the same oil.

Today I stripped one of the tables of all the wiring, motor, panels and hardware, cleaned it all and it's ready to go in for powder coating, bright red, should look good with black or chrome tonearm. It's a shame as the finish is darn near perfect but I just don't like baby blue, I'll probably keep the other one original.

I'm just going to coat the top surface, and only what's visible, keeping the underside and under the platter area clean so I can put damping pads on. My thickness planer arrived today courtesy of my Dad and I tried planing a few pieces of wood I set aside thinking they were something other than SPF, still don't know what it is but it has some nice grain and texture. My plan is to build the plinth core from baltic birch CLD then cover it in nicely planed trim wood of various colours and grain, it should look good, maybe add some copper accents or ??? Still stewing on the whole look but I have time.

More later.

Cheers

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Back on the Russco project today working on the motor and its mount. I didn't dismantle the motor, I didn't see a need to, but oiled the bearings and gave it a good wipe down.

I noticed it makes a fair bit of noise, and has some vibration, certainly noticeable but maybe normal, it's my first idler. I made a recording with my phone which was held about 4" from the motor from both the side and top. Since our goal is to reduce noise and rumble and it starts at the motor, I am wondering if maybe some isolation right at the motor is in order? Maybe a thin sheet of rubber between the motor and frame, small o-rings around the bolts etc. I know motor alignment and stability is important but if done right shouldn't effect anything.

Has anyone ventured down this path?

Thanks!

https://drive.google.com/file/d/1DRVoAtc9l4_M0K7o00FoNggkO2CI2BVL/view?usp=sharing

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Just by the sound, it sounds like it’s vibrating, a little motor sound will not be transferred but any vibration will,….it shouldn’t be vibrating.

Andy
 
I'm not sure how to get rid of the motor vibration, I took it all apart and everything was spotless inside, shaft is clean, bearings look good and are tight, no play, the ball was clean. I oiled everything and put it back together, then mounted it using little cork gaskets I found years ago, whatever space they take up can be accounted for in the suspension mounts, shims, washers etc. .

Then I went to town on the Dynamat on the motor and suspension frame, lowered the voltage to 115VAC and there is much less vibration now and overall is MUCH quieter, the damping is something I highly recommend. I made another recording as well.

I would still like to know what is causing the motor vibration, if it is actually abnormal. Before the damping, I could fell tingling in my fingertips, much less now.

Your thoughts?

Cheers

https://drive.google.com/file/d/1DRukUDoxwnUEffhQVsHiy_pt3FgWhB7f/view?usp=sharing

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We need @BillWojo to chime in…all I’m able to add is that reducing voltage will help, but it still shouldn’t vibrate, at least mine doesn’t. Have a bit of motor running sound when right at the table, but that doesn’t get transferred.

An old trick I’ve used successfully is to leave the motor case bolts kinda loose and while holding the running motor in one’s hand, tap it with a mallet…that works well on some motors.
 
Thanks Andy, agreed, would be good to hear from Bill.

Heeellllooooo @BillWojo can you hear me now?

I was rereading @MisterDK thread and he made a wood idler arm, I would like to know Duane, how that sounded and how it worked. I think wood would be better than my idea of Delrin. I have a nice chunk of maple which I could mill into the proper shape. Duane, how did you get the shafts out of the original idler arm?

I may be chasing a non audible problem at this point, but it is fun to experiment.

I'm listening for input.

cheers
 
ve7kilohertz said:
Thanks Andy, I ended up using ISO 46 hydraulic oil, heated it on the wood stove then let it cool in the can of oil overnight, it should be good now. When the table is going back together I will fill the well with the same oil.

Today I stripped one of the tables….cleaned it all and it's ready to go in for powder coating, bright red, should look good with black or chrome tonearm. It's a shame as the finish is darn near perfect but I just don't like baby blue, I'll probably keep the other one original.

I'm just going to coat the top surface, and only what's visible, keeping the underside and under the platter area clean so I can put damping pads on….Still stewing on the whole look but I have time.

More later.

Cheers

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Paul, If you haven’t sent it out for powder coating just yet - I wanted to mention WRINKLE FINISH. I believe you can get it done by that method of finishing, besides the old “spray bomb” method but not sure how nicely it comes out in comparison… I happen to love wrinkle finish, for when I was a kid, it was on practically everything industrial.. It’s tough and durable and lasts for a long time. Takes some patience to use, but if you know the trick, a spray bomb is relatively easy - (use thin, multiple layers at different directions, prewarm both part and your spray up to and around 70ºF, then when wrinkle is barely starting, oven bake at around 80ºF). You’ll need to research brand for a spray bomb… Or, ask the powder coater..
Done on my AR XA table around 1986:

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ve7kilohertz said:
Thanks Andy, agreed, would be good to hear from Bill.

Heeellllooooo @BillWojo can you hear me now?

I was rereading @MisterDK thread and he made a wood idler arm, I would like to know Duane, how that sounded and how it worked. I think wood would be better than my idea of Delrin. I have a nice chunk of maple which I could mill into the proper shape. Duane, how did you get the shafts out of the original idler arm?

I may be chasing a non audible problem at this point, but it is fun to experiment.

I'm listening for input.

cheers
Click to expand...

Paul, I didn’t remove those 3/8” shafts. I happened to have some hollow ones I used, held in place with stainless 10/32 bolts & stainless Nyloc nuts. The bolts were made a tight fit by placing ‘em inside silicone fuel tubing for model planes (a very tight fit..). I *think* the metal hardness of the two shafts may be too soft but I haven’t recently checked for wear.
The wooden idler arm looks nice enough - but I think it transfers more noise than a more dense arm, like the original, would.. When I have funds to buy one from Serge in Ukraine (and if he’s still making them), I’ll buy one of his made from brass.. I believe V.2 is correct for the Studio Pro B.

https://www.karmadon.net/shop/russco-broadcast-turntable-idler-shaft/

Duane
 
Thanks Duane,

I haven't sent it in for powder coat yet, but still want to, or fire up my spray gun and paint it myself. I still want to have this one bright red. BTW, I also love black wrinkle finish and have 2 brand new cans here ready for my EAR834 I'll be scratch building soon, I want to have exposed tubes on top, black wrinkle finish chassis.

I think I'll leave the stock idler arm for now until I get the table reassembled and if need be, build one then. I have too many variables right now and need a baseline for comparison to begin with.

Thanks for the input.

Cheers
 
@ve7kilohertz , do you have access to a dial indicator⁹ setup? Might want to check and see if your motor spindle has a slight bend, look to see if the area that drives the idler wheel is wobbling around. I wouldn't want to see more than 0.001 total indicator runout (TIR). With the long slender spindles on these motors it doesn't take much of a blow to get runout and vibration.
I found mine running out about 0.0015 and using a drift with a mallet I was able to get it to about 0.0005 TIR using small taps.
Aside from that I just took the motors apart and cleaned/ lubed the bearings. Also check them for play, should be very little.
Finally as Andy stated, as you assemble it tap the housing lightly as your snugging the bolts, it can get you into a smoother running position.
If your careful, there s nothing tricky about working on these motors, just watch the placement of shims and washers. They come apart same as a big industrial motor meaning they were made to be serviced.
A few other things, axles for making your own idler bracket is best done using industrial dowle pins. Standard size for a 3/8 pin is 0.3750 to 0.3752. I use a 0.3745 reamer diameter in metal but you might want to go to 0.3740 for plastic like Delrin. As far as material goes for the bracket I like Andys suggestion to try Delrin. Possibly it can be beefed up with a lot more material in the areas that need it. I suspect it would be very quiet if used along with Abe's Delrin idler wheel.

BillWojo
 
BillWojo said:
@ve7kilohertz , do you have access to a dial indicator⁹ setup?
Aside from that I just took the motors apart and cleaned/ lubed the bearings. Also check them for play, should be very little. BillWojo
Click to expand...

Got the dial indicators from the shop and set it up on the spindle, only a needles width of wobble, see attached link to a video I recorded, gauge markers are .001".

Going to redo my spindle bearing today using the newly arrived Delrin rods. Mmmm, actually, I don't think I will, forgot, I need to find a collet setup for my lathe, I have the collets but no way to use them (that I know of).

Here is my measuring setup and video link.

Cheers

https://drive.google.com/file/d/1DVLoVSo8J4dIU4ne7BvG0wTdf_kLdkZR/view?usp=sharing

IMG_4502.JPG
 
ve7kilohertz said:
Got the dial indicators from the shop and set it up on the spindle, only a needles width of wobble, see attached link to a video I recorded, gauge markers are .001".

Going to redo my spindle bearing today using the newly arrived Delrin rods. Mmmm, actually, I don't think I will, forgot, I need to find a collet setup for my lathe, I have the collets but no way to use them (that I know of).

Here is my measuring setup and video link.

Cheers

https://drive.google.com/file/d/1DVLoVSo8J4dIU4ne7BvG0wTdf_kLdkZR/view?usp=sharing

View attachment 2854783
Click to expand...

To be a bit nitpicking, my approach to this test is with the motor powered up….
 
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