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Rek-O-Kut Turntables - ROK

kismetnarb said:
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Good to hear regarding your capstan. I agree with you about mechanism driven turntables... I'm just trying to have it engage at all 3 speeds. I'll look into to dealing with the capstan and report back.
Thanks for your response
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I recommend you to adjust precisely the height of the washers that supporting the idler wheel. The adjustment need to be precise because the motor pulley steps are not tall enough to allow room for adjustment. In my case, I wanted to used use PTFE washer exclusively for that task, and was limited by their thickness.

It is strange that Rek O Kut didn't design the B12 to make full contact with the motor pulley at 78 RPM. Using for a long time exclusively this speed will use unevenly the elastomer portion of the idler wheel, degrading the noise performance of turntable.
 
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SidSmith said:
I recommend you to adjust precisely the height of the washers that supporting the idler wheel. The adjustment need to be precise because the motor pulley steps are not tall enough to allow room for adjustment. In my case, I wanted to used use PTFE washer exclusively for that task, and was limited by their thickness.

It is strange that Rek O Kut didn't design the B12 to make full contact with the motor pulley at 78 RPM. Using for a long time exclusively this speed will use unevenly the elastomer portion of the idler wheel, degrading the noise performance of turntable.
Click to expand...
Thanks for the recommendation. The idler is at the right level in each speed for the capstan, however I'm still having the same issue. The washers are correctly placed as well. It's a mystery.
 
I’ve never seen a hysteresis (H) motor of any table that was running not turn within a few rpm of the design specifications even at low voltage…

I’d check the pressure spring assembly, see if anything is amiss, make sure the wood dowel is intact and turned in the right direction …
 
According to Serge at Karmadon (turntable restoration) the diameter spec of the capstan for 33.3 = 5.18mm, 45 = 6.98mm, and 78 = 12.1mm. That is for an early model rondine deluxe B12H with an idler brass bushing diameter of 6.35mm (.250"). I have also confirmed its best to have the motor on hand when replacing the capstan. "It is always preferable to have the motor here to measure shaft errors and fit the capstan accurately while measuring the errors."
 
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adnick said:
I’ve never seen a hysteresis (H) motor of any table that was running not turn within a few rpm of the design specifications even at low voltage…

I’d check the pressure spring assembly, see if anything is amiss, make sure the wood dowel is intact and turned in the right direction …
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The pressure assembly is correct. wood dowel rounded corners are facing down. what about the spring tension screw? would it help if I adjusted it?
 
I'm curious if anyone knows if the amount of washers placed between where the motor bracket attaches to the center of the table would effect the alignment of the capstan - tilting it in one direction or the other depending on the amount of washers. see photo.
 

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kismetnarb said:
I'm curious if anyone knows if the amount of washers placed between where the motor bracket attaches to the center of the table would effect the alignment of the capstan - tilting it in one direction or the other depending on the amount of washers. see photo.
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You seems to have 3 washers fibre between the table frame (105) and the shift lever sub assemblie (100). According to the part list exploded view, you shoud have just one (82) Washer Fibre 3/4 x 1/4 x 1/16 there.

I doubt it will change something, but it is a departure from the original design.
 
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Selmerdave said:
^ I had that problem with the delrin idler wheel, and while it was difficult to find the happy medium with the original wheel I did eventually get there. I haven't checked 78 since I only use 33 and 45, and I've had to accept 33.25 and 44.8 or so, but that works for me and is preferable to adjusting speed when I change from one to the other.
Click to expand...

If you have a dim bulb tester, put in a 40 watt bulb and plug the turntable into it, this will make speed adjustments easier especially if they are running a bit too fast, it generally reduces W&F a bit also….this is an old trick that gets overlooked.

This works better than a variac and/or a bucking transformer, not sure why, but mine reacts even a bit better when plugging the dim bulb tester into my bucking transformer.

Many may already know this but just in case….

Andy
 
adnick said:
If you have a dim bulb tester, put in a 40 watt bulb and plug the turntable into it, this will make speed adjustments easier especially if they are running a bit too fast, it generally reduces W&F a bit also….this is an old trick that gets overlooked.

This works better than a variac and/or a bucking transformer, not sure why, but mine reacts even a bit better when plugging the dim bulb tester into my bucking transformer.

Many may already know this but just in case….

Andy
Click to expand...
Interesting, maybe I'll try that. I don't have an issue with speeds too fast or too slow, with the delrin wheel I had some physical noise that was audible from the listening position and when adjusted for 33.33 speed it wouldn't make contact at 45, so 45 required adjusting the wheel. The sound from the table was a little better but the physical noise was an annoyance, so I've gone back to the original wheel which gives me both speeds at the same setting and very close to silent.
 
Selmerdave said:
Interesting, maybe I'll try that. I don't have an issue with speeds too fast or too slow, with the delrin wheel I had some physical noise that was audible from the listening position and when adjusted for 33.33 speed it wouldn't make contact at 45, so 45 required adjusting the wheel. The sound from the table was a little better but the physical noise was an annoyance, so I've gone back to the original wheel which gives me both speeds at the same setting and very close to silent.
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Had the opposite experience with Delrin idlers, on several tables, but just got a bad Audiosilente idler for my Garrard so mistakes can be made by the best of them…

One thing of note, the dim bulb trick was used most often to reduce rumble….it certainly reduces voltage but my guess is that it cleans up or filters the power source?
 
Yeah I'll have to check that out. I don't have a lot of rumble, it's quite acceptable but there's a little there on quiet records.
 
Hi all! I’m working through my deluxe b12h and was hoping for a bit more help. I started another thread impulsively but I’ll hop over here now. Man it’s easy to get lost in all these pages, took me a while but I got through them. I’ve already received a lot of great help so thanks to all who’ve been a part of that!

One point is confirmation: I have the early Rondine Deluxe with the pop-up adapter so I likely need the 1/4 in ball bearing correct?

Next is that during the process of replacing all the grommets and putting in the nice new idler I discovered that there were no washers above the idler installed, just the two below. I should probably replace all these anyway but what are the latest good sources for these? I think there were some old links to ‘bay folks with Teflon RC washers, but those were gone. Also there was one reference to a McMaster Carr PFTE washer but then I don’t think it worked or was the wrong size. If anyone could help I’d love to get new of both the thick and thin needed.

Also, I was fortunate enough to get a great price on a Micropoise arm from a member here, and an antiskate balance weight for it from another member. I ended up buying a new headshell from Best off the ‘bay, I got a backup for my AR-XB from them recently and was happy so I went with that thinking some day I’ll figure out a more original solution but this will do for getting it going. When I tried installing it, it seems to not quite fit all the way in and is a mm or two loose/long, it does work with the collar but it’s not tight. Has anyone experienced this or alternatively used those headshells successfully with a Micropoise?

Lastly, I did a clean out of the bearing in an initial cleaning/polishing. I replaced the oil using the zoom spout white lily sewing machine oil that was recommended for the AR-XB, but I know that the original specs call for the straight 20wt. Is the white lily too thin? I have various oils from my 40s car around so I can change it, but if it’s not essential I’ll wait and use what I put in for now.

Thank you!
 
May need larger ball. Try increasing size till you get clearance. If you can't find them, let me know and I'll send a couple different sizes that work in B12.

Washers help position the idler in relationship to the drive pulley. You want it roughly centered in each speed.

20wt oil is good but I'm not religious about it. If white lilly works, then it works. I use Anderol (available on AMazon) or 3 in One motor oil (it's 20wt , not the normal 3 in One)
 
Thanks for the input and the offer hirscwi, very generous. I can get bearings, I’m planning on ordering a ceramic one to replace the metal, I just want to make sure it’s right and same for the bushings on the idler. Ideally I can order them both from a place like McMaster carr or other since my spouse is starting to ask about all the strange charges I’ve been making and the “car parts” excuse is running thin due to the size of the packages!

I forgot another ROK question, I’m going to use the original plinth for now but it has no feet. I haven’t seen much here about replacement feet, has anyone found replacements or good reasonably priced upgrades? Esoteric has a lot of options (the bay is overwhelming) but no info on if they will directly replace the stock feet. Reasonable price is also because someday I might build a different plinth so I don’t want to put $$$ into this one now.
 
2325Veepster said:
Thanks for the input and the offer hirscwi, very generous. I can get bearings, I’m planning on ordering a ceramic one to replace the metal, I just want to make sure it’s right and same for the bushings on the idler. Ideally I can order them both from a place like McMaster carr or other since my spouse is starting to ask about all the strange charges I’ve been making and the “car parts” excuse is running thin due to the size of the packages!

I forgot another ROK question, I’m going to use the original plinth for now but it has no feet. I haven’t seen much here about replacement feet, has anyone found replacements or good reasonably priced upgrades? Esoteric has a lot of options (the bay is overwhelming) but no info on if they will directly replace the stock feet. Reasonable price is also because someday I might build a different plinth so I don’t want to put $$$ into this one now.
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Lots of choices for feet. Good rubber ones available from Parts Express. If you want turned aluminum ones, there are lots of choices on eBay - from $20 to $200. Some also on Amazon.

I'm less worried about the use of ceramic than Robert but I don't see any advantage (I've used both). Add a PEEK washer to the thrust plate if you can find such. I don't think you'll need to replace the bushings on the idler.
 
^^^ +1 n adding a PEET or similar thrust plate, I’ve also had very good luck with HDPE and similar plastic balls, however they are not an add and forget type of modification. Have had some in use for over a year now, so they don’t wear out quickly….

VR
Andy
 
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