Rek-O-Kut Turntables - ROK
- Thread starter jcmjrt
- Start date
I'm late to the party... but I have arrived! After messing with all manner of ROKs for the last 3 years I've finally landed the Deluxe w/ Ashland motor. Of course, I'm having a little trouble that I can't sort out.
The table is struggling to engage 78 rpm ... let me explain.
To get 33.3 I've needed to adjust the idler pressure pretty high. Sounds great. 33 and 45 work fine. When I switch to 78 though, there isn't enough clearance between the pulley and the idler for the idler to drop down to the 78 portion of the pulley. It stays stuck on the 45 section.
If I back off the idler tension it drops down fine, but I'm spinning at 33.7. Suggestions?
The table is struggling to engage 78 rpm ... let me explain.
To get 33.3 I've needed to adjust the idler pressure pretty high. Sounds great. 33 and 45 work fine. When I switch to 78 though, there isn't enough clearance between the pulley and the idler for the idler to drop down to the 78 portion of the pulley. It stays stuck on the 45 section.
If I back off the idler tension it drops down fine, but I'm spinning at 33.7. Suggestions?
Not had one that couldn’t be tamed though. Idler washers in place?
I think I figured it out... hard to pin down what exactly fixed it though.... there were no washers above the idler, so adding some there helped to keep it from riding too high, but I think it has something to do with cleaning these 2 points and hitting with some 3-1 oil 
I'm not sure exactly of their function but they seem to need to move freely when shifting between speeds.
Love this thread and these tables! Couldn't be more thrilled with the Deluxe. Always assumed the Ashland was going to be grungy noisy and just pure brute force .... I was wrong - wow. Totally silent, hard to tell it's even on just by looking and listening. What a feat of engineering. And damn this comes to speed faster than my JVC QL-5.
I thought I was done once I got the B-12gh up and running... I think I'll stop now.
I'm not sure exactly of their function but they seem to need to move freely when shifting between speeds.
Love this thread and these tables! Couldn't be more thrilled with the Deluxe. Always assumed the Ashland was going to be grungy noisy and just pure brute force .... I was wrong - wow. Totally silent, hard to tell it's even on just by looking and listening. What a feat of engineering. And damn this comes to speed faster than my JVC QL-5.
I thought I was done once I got the B-12gh up and running... I think I'll stop now.
adnick
Addicted Member
That’s great Fred
In my experience those washers have to be in place….the Rondine Deluxe is one of the quieter tables I’ve had, that was after cleaning and a new idler of course.VR
Andy
kismetnarb
New Member
Hey all, I have a Rondine Deluxe with a B12H motor. My goal is to get it running at a reasonably accurate speed switching from 33, 45 and 78. I have all the idlers available, Ukrainian, Russian, Terry's Rubber Rollers, and Abe's (from Vermont). I'm using the correct oil and bearing, washers are properly placed and I'm familiar with how to adjust the speed correctly. I can get it to run accurately at 45, but then it's too fast in 33. When I adjust it to run at 33, the idler (tried all of them) doesn't make contact (spin the platter) at 45 or 78. Does that indicate the capstan is not aligned correctly? Is there away to adjust it's tilt? All bushing's have been replaced as well.
Andy, you're familiar with this table... wondering if you or anyone here can advise. I'm using a KAB speed strobe to measure speed (more accurate than an app).
Many thanks!
Andy, you're familiar with this table... wondering if you or anyone here can advise. I'm using a KAB speed strobe to measure speed (more accurate than an app).
Many thanks!
^ 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.
adnick
Addicted Member
You’ve got something out of alignment if it’s playing at 45 then won’t engage at 33, it’s not an idler problem in and of itself, never had an issue myself with my Rondine Deluxe, but only have a TR12H and TR43H at the moment. The idler pressure screws are called “fine speed adjustment screws” by ROK, but that’s not what’s causing your issue..
VR
Andy
Just a thought, if the idler is sitting too low then some contact with the 45 section of the pulley may be causing it to run fast.
With the platter off, can you verify that when you switch speeds the idler is moving up and down to the correct part of the pulley?
With the platter off, can you verify that when you switch speeds the idler is moving up and down to the correct part of the pulley?
I would love to know how to adjust the alignment of the motor and idler if anyone has info...
kismetnarb
New Member
Thanks, really appreciate your responses!
The idler is at the correct level for the capstan at all speeds. Andy, it's actually your old rondine deluxe that I'm trying to adjust. When adjusted at 45 (99.99% accurate) and then switching to 33, it's 3% too fast. When I then adjust it to run at 33 (99.99% accurate) and switch it to 45 and 78 there's not enough pressure for the idler to engage with the platter. That's all of the idlers (2 1/2" diameter). This is what makes me think the capstan in misaligned or slightly tilted. Does anyone know how to adjust the capstan tilt? Or any other suggestions would be greatly appreciated. The capacitor tests good.
The idler is at the correct level for the capstan at all speeds. Andy, it's actually your old rondine deluxe that I'm trying to adjust. When adjusted at 45 (99.99% accurate) and then switching to 33, it's 3% too fast. When I then adjust it to run at 33 (99.99% accurate) and switch it to 45 and 78 there's not enough pressure for the idler to engage with the platter. That's all of the idlers (2 1/2" diameter). This is what makes me think the capstan in misaligned or slightly tilted. Does anyone know how to adjust the capstan tilt? Or any other suggestions would be greatly appreciated. The capacitor tests good.
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kismetnarb
New Member
Perhaps I need a new capstan...
kismetnarb
New Member
Does anyone know the spec diameter of each speed of the capstan for an idler with a brass bushing diameter of .250? I know people have speculated on it here, but it would be good to know the original spec. Also, the specs for the capstan with the smaller idler brass bushing of .220?
thanks
thanks
SidSmith
Active Member
My Rondine Deluxe is difficult to adjust precisely. The manual mention that you must adjust the speed at 45 RPM only. A more practical way will be to adjust the speed you listen the most.
My observations are that the original Idler do not fully engage the 78 RPM speed on the motor shaft. Just the lower part of the cross section of the O-ring engage.
My original idler oscillate and we remade a new one respecting the originals sizes. We remade a new motor shaft too.
The cross section size of the rubber, in my case nitrile square O-ring, and the number of washer and their thickness, matter. The new O-ring need to wear out a bit before attain is balance state, which improved speed and most importantly, quietness of operation.
A larger cross section mean a greater surface of contact with the shaft, which cause more friction and ultimately greater speed.
I tried to adjust all three speed precisely, but it was not possible to have satisfacting result for all three.
Ultimately, I set up my table by dissengaging the 78 RPM speed completely (I do not listen to 78 RPM records anyway) by raising the idler wheel with washer thickness.
After a 15 minutes warm up, speed reading are 33.3 RM and 45.3 RPM (±0,3%) by a rudimentary tachometer and double check with a strob.
All of this made by lot of trial and error.
My observations are that the original Idler do not fully engage the 78 RPM speed on the motor shaft. Just the lower part of the cross section of the O-ring engage.
My original idler oscillate and we remade a new one respecting the originals sizes. We remade a new motor shaft too.
The cross section size of the rubber, in my case nitrile square O-ring, and the number of washer and their thickness, matter. The new O-ring need to wear out a bit before attain is balance state, which improved speed and most importantly, quietness of operation.
A larger cross section mean a greater surface of contact with the shaft, which cause more friction and ultimately greater speed.
I tried to adjust all three speed precisely, but it was not possible to have satisfacting result for all three.
Ultimately, I set up my table by dissengaging the 78 RPM speed completely (I do not listen to 78 RPM records anyway) by raising the idler wheel with washer thickness.
After a 15 minutes warm up, speed reading are 33.3 RM and 45.3 RPM (±0,3%) by a rudimentary tachometer and double check with a strob.
All of this made by lot of trial and error.
adnick
Addicted Member
Oh, that’s great, but the second part of your adjustment process doesn’t make sense, or at least I’ve never encountered a similar situation on several I’ve built….The same guy who makes the Delrin idlers can make capstans out of the original material…it’s certainly not an electrical problem, many people use to run them with what we now call dim bulb tester with a low watt bulb to lower the voltage..That table is a very early model, and takes the larger version idler bushing , (just for future reference)
Andy
adnick
Addicted Member
That’s a great write-up, it’s a very hard to explain process, and the adjustments are extremely sensitive….and your also correct about checking speed with more than one device, the most accurate is a stop watch over a several minutes
kismetnarb
New Member
I'll probably look into getting a new capstan. But I guess a lot of people say it's necessary to have the motor on hand to make a proper capstan. you're not aware of a way to adjust the capstan tilt? and yes, the idler bushing is the larger one at .250". The newer smaller one is .220". I was referring to the idler's outer diameter of 2.5"
adnick
Addicted Member
Yes understood you were talking about outer diameter of the idler….
Couple of thoughts:
Had the capstan made for for my TR43 without issue
Never use 78 much, but I wouldn’t expect a mechanism driven machine to keep perfect speed when switched between speeds without minor adjustment.
Certainly adjust my other idlers between speed changes, but I’m also not constantly checking speed unless it’s obvious…
VR
Andy
Couple of thoughts:
Had the capstan made for for my TR43 without issue
Never use 78 much, but I wouldn’t expect a mechanism driven machine to keep perfect speed when switched between speeds without minor adjustment.
Certainly adjust my other idlers between speed changes, but I’m also not constantly checking speed unless it’s obvious…
VR
Andy
kismetnarb
New Member
\
Thanks for your response
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