Groomlakearea51 Posted August 12, 2011 Share Posted August 12, 2011 Given that Pioneer made RTR's that required lubrication, is it possible that the oil used was the RTR oil usually found in small plastic bottles that came with the decks? Another possibility..... There is a type of oil made for air tools (in the small plastic bottles...). That oil is "dripped" into the air hose feed line of the tool. If the tool is working properly and not worn out, it usually seems to remain inside the tool during, say about 500 nails/ staples, brads, etc. Perhaps that oil would work as well. Also, when I look at the picture of the "washers", It appears that the air in the piston is supposed to "leak" past, thus slowing the piston down. But.... if there is only a small quantity of oil in the bottom of the brass piston sleeve, only enough so that when the tuone-arm is "down" on the LP or in the down position, those two washers should be bathed in the oil. Thus the amount of oil should only be just enough to cover at least one of the washers. When the tone arm is lifted, the oil remains on the washer as it goes up, and "dampens" or slows down the arm when released. The alternative is the piston sleeve is only filled to where the lower washer is located, when the arm is fully raised. That may be the reason for the position of the side screw. Leaks.... I would think that if the assembly is cleaned really well with some type of degreaser, then isopro alcohol, then there sould be no leaks when re-assembled. Just some musings..... [H] Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 Also, when I look at the picture of the "washers", It appears that the air in the piston is supposed to "leak" past, thus slowing the piston down. But.... if there is only a small quantity of oil in the bottom of the brass piston sleeve, only enough so that when the tuone-arm is "down" on the LP or in the down position, those two washers should be bathed in the oil. Thus the amount of oil should only be just enough to cover at least one of the washers. When the tone arm is lifted, the oil remains on the washer as it goes up, and "dampens" or slows down the arm when released. The alternative is the piston sleeve is only filled to where the lower washer is located, when the arm is fully raised. That may be the reason for the position of the side screw. Marshall, these are possible scenarios I'd envisioned as well. I have some Marvel Air Tool Oil which was suggested as a lubricant (can't remember if it was for the spindle or the motor bearings) for my Thorens TD-124 (by Steve at The Analog Dept.). Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted August 12, 2011 Share Posted August 12, 2011 Yah... I've been using Marvel Tool Oil for years now as an alternative to the old "3 in 1 Oil". LOL!! [H] Quote Link to comment Share on other sites More sharing options...
Arkytype Posted August 12, 2011 Share Posted August 12, 2011 Fini--- It looks like the bearing assembly may be sintered bronze which is usually impregnated with oil. However, that alone probably wouldn't allow for a damped tone arm lowering. The screw on the side of the cylinder and the two disks may be clues. The screw on the side may be used to adjust the rate of the arm's descent once the lever is set to "lower" position. That would suggest that the cylinder would use air as the damping medium. Since the two discs don't have an O-ring between them, I doubt the 0.017" gap between the larger one and the side walls of the cylinder would trap enough air to be useful. That leaves only one logical solution which you found on line---high viscosity silicone-based "fluid". At this point one could argue for coating only the walls of the cylinder with the stuff or filling the cylinder full. If the 300,000 cst is as thick as cold molasses, then I'd opt for coating only the walls---otherwise it might take several minutes for the tonearm to drop. The side screw tells me the silicone is used as a seal between the discs and the cylinder and air is being used as a spring to dampen the rise and fall of the tonearm. The side screw sets the rise and fall time of the arm. I am surprised there is no seal to keep the fluid from leaking out over time. Perhaps the turntable was stored on a hot environment and the original fluid's viscosity changed and it ran out? Lee Quote Link to comment Share on other sites More sharing options...
Marvel Posted August 12, 2011 Share Posted August 12, 2011 Yah... I've been using Marvel Tool Oil for years now as an alternative to the old "3 in 1 Oil". LOL!! It's not quite what I had envisioned... [:#] Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 If the 300,000 cst is as thick as cold molasses, then I'd opt for coating only the walls---otherwise it might take several minutes for the tonearm to drop. The side screw tells me the silicone is used as a seal between the discs and the cylinder and air is being used as a spring to dampen the rise and fall of the tonearm. The side screw sets the rise and fall time of the arm. Lee, If I coat only the walls of the cylinder, won't it eventually slump down into the bottom of the cylinder? Would you suggest then that the cylinder be filled up to the level of the discs at their lowest point of travel, the discs being "dipped" into the solution each time it's down? Remeber, though, the piston only travels about 1/8". Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 A couple more photos and notes. Here's the cylinder cap, the side that contacts the cylinder rim. Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 Here's the cyinder with the piston in. With the cap on, it sits a bit deeper (the cap pushes against the retaining clip). When it is all assembled and upright, the bottom of the side hole is approximately at the level of the middle of the lowest disc. This makes me think that maybe the side hole IS a filling port, or a drain port if one overfills the chamber and allows the excess to drip out. Is this clear? Basically, if the oil level is at the bottom of the hole, the bottom disc is submerged in oil (at its lowest point of travel). Does this make sense? Quote Link to comment Share on other sites More sharing options...
MikeFord Posted August 12, 2011 Share Posted August 12, 2011 Go to a hobby store and buy some oil used in RC car shocks, thats what the lifter thing is a damper/shock. Much as I love Marvel Mystery oil, I would not suggest it or silicone oil. Marvel is a mix of oils, some of which evaporate. Silicone oil migrates, it wants to cover every surface, bleh, wouldn't use, unless that turns out to be what the RC shocks use. Quote Link to comment Share on other sites More sharing options...
LarryC Posted August 12, 2011 Share Posted August 12, 2011 If the 300,000 cst is as thick as cold molasses, then I'd opt for coating only the walls--- I think I saw 3 different viscosities of silicone oil available, so you could try the middle if you think 300k is too thick. I still can't figure what the spring is for, unless it's needed against thick oil. I do not think air is involved.I doubt I'd ask him myself, but AJ Conti, world-class TT engineer and president of Basis Audio, might have some diagnostic suggestions about what you're looking at, and pretty good guesses at the viscosity needed. He's been very approachable in the past, but I don't know now because he probably doesn't sell many of his expensive wares to typical audiophiles. Anyway, see http://www.basisaudio.com/products.html See "Damping solutions" under http://www.basisaudio.com/docs/tnm_v4_specs.pdf. He uses thick, viscous, silicon oil. My Vector tonearm drifts down very slowly when I trip the lever down -- only tonearm weight, no springs involved. Quote Link to comment Share on other sites More sharing options...
LarryC Posted August 12, 2011 Share Posted August 12, 2011 On second thought, I'd suggest you not contact Conti. Vinyl engine and like sources show lots of frustrated DIY'ers who have old failed vintage tonearm lifts and can't fix them. Maybe Needle Doctor knows somebody. Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 On Clipped & Shorn's suggestion, I called Kevin at KAB. He actually has one of these turntables, but has never taken apart of serviced the cueing mechanism. Heck of a nice guy, though! Quote Link to comment Share on other sites More sharing options...
T2K Posted August 12, 2011 Share Posted August 12, 2011 I can't help you fini but I was just wondering...are you going to post here if you figure out the solution or are you going to maybe come out with a printed solution guide that includes necessary parts/tools/oil for like $149.95 ? Just wondering. Keith Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 I can't help you fini but I was just wondering...are you going to post here if you figure out the solution or are you going to maybe come out with a printed solution guide that includes necessary parts/tools/oil for like $149.95 ? Just wondering. Keith That's a darn good idea, Keith! Let's see, if I sold ten of them, I'd probably be paying myself about $4/hour for the time and money I've already invested in this dumb project...Will you be my manager?? Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted August 12, 2011 Share Posted August 12, 2011 Of course in the last 24+ hours that we have been talking about this Fini could have tried every idea we have come up with. [] Quote Link to comment Share on other sites More sharing options...
fini Posted August 12, 2011 Author Share Posted August 12, 2011 But I just hate to do things twice. It drives everyone crazy. Quote Link to comment Share on other sites More sharing options...
T2K Posted August 13, 2011 Share Posted August 13, 2011 I remember reading something about this years ago. I can't seem to find it in any links that I have saved. I'll see if I can find my Sansui (1970's) service manual. Keith Quote Link to comment Share on other sites More sharing options...
fini Posted September 10, 2011 Author Share Posted September 10, 2011 I finally got around to trying a few oils. It is a royal PIA to put this back together, due to the super-small screws and my enormous mitts. The 20W turbine oil was too thin. The arm still dropped too fast. Next I tried the 300,000 cst silicone oil I had on hand WAAAY too thick. Might work with 2-pound tracking force. I have various motor oils here I could try. A hobby shop in town (catering to RC cars and planes) has various silicone lubes. I might try them. Anyone have any other suggestions? In this application, would 20W-50 motor oil act more like 20-weight, or 50 weight? Quote Link to comment Share on other sites More sharing options...
Marvel Posted September 10, 2011 Share Posted September 10, 2011 In this application, would 20W-50 motor oil act more like 20-weight, or 50 weight? I wouldn't think you would want to use a detergent oil, but it's just my opinion.Bruce Quote Link to comment Share on other sites More sharing options...
fini Posted September 10, 2011 Author Share Posted September 10, 2011 Bruce, mostly I'm trying to figure out the viscosity to use. The silicone oil at the hobby shop comes in a whole range of weights. Quote Link to comment Share on other sites More sharing options...
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