Kevinkr, I know how you reconditioned the original bushings is SOP and in fact I've gone through the same process myself, but I've been considering trying to reproduce the vacuum process we've heard was originally used to charge the bushings with oil. I have two vacuum sources I'm considering hooking up via tubing to a sealed jar. The first source is a pretty big vacuum pump, originally used to power a vacuum table. The other source anybody can pick up - a "SealSaver", which includes tubing and a stopper so you can re-seal bottles.
Would putting the bushings in an empty jar, sealing the system, then turning on the vacuum pump drive out the majority of the old oil? Would repeating the process with the jar filled with new oil drive out the air introduced in the previous step?
Perhaps the best way to approach it is to start with the weakest vacuum source, but if anyone has thoughts or real-world experience that would help me set up this little experiment, I'd love to hear them.
Would putting the bushings in an empty jar, sealing the system, then turning on the vacuum pump drive out the majority of the old oil? Would repeating the process with the jar filled with new oil drive out the air introduced in the previous step?
Perhaps the best way to approach it is to start with the weakest vacuum source, but if anyone has thoughts or real-world experience that would help me set up this little experiment, I'd love to hear them.
I have seen a low powered version and it was very good. I was never sure what the motor was exactly. It seemed to be Papst own idea . Hysterisis is said to close to synchronous. As load is applied the speed reduces . If the load is small the speed is almost as good as traditional synchronous. I took a Papst apart once. It did not look like a synchrous. I have no idea if it was typical. 3 phase seems ideal. One idea I saw used was a DC motor from a tape recorder. The speed is set inside the motor. As the man said that is where speed should be measured.
How about rinsing TD-124 motor bush bearing few times in alcohol to dissolve and remove old oil, lightly heat it to clear residue, put in vacuum jar filled with oil so air is replaced by new oil ?
Regards
addition : I guess if one doesn't have vacuum pump (taking precaution) gently heating an air tight glass bottle and filling it with moderately heated oil and bush in it and closing it, pouring cold water over it will create vacuum too.
Regards
addition : I guess if one doesn't have vacuum pump (taking precaution) gently heating an air tight glass bottle and filling it with moderately heated oil and bush in it and closing it, pouring cold water over it will create vacuum too.
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If you can solder you can easily build my design which will do 50Hz and since it is crystal controlled it is very stable, distortion is quite low. (I use a sixth order sallen-key LPF to make clean sine wave.) The design is discussed in another thread in this forum. It's not very expensive to make.
Heating the oil facilitates it flowing into the tiny pores in the sintered bronze (oilite), but a vacuum pump would not hurt if you had one. I'm not sure cold oil would flow into the tiny pores of the bushing even with a vacuum pump if the oil were not warm, and you need to cool the bushings so that the coil stays in place. Seem like additional complication, it won't hurt, but I am not sure it really helps either.
I doubt it would work at all for removing the old oil given that the old oil is a sludgy gell with little or no entrapped air mixed in.
I wonder what this constant desire is to complicate a simple and proven process - no special equipment is required and the results are excellent. We all want to put our stamp of individuality on the things we do, but sometimes the best trail has already been blazed and experience tells me this is probably the case here.
I have a Papst TD-124 3 phase motor and a Mark Kelly controller for it, I just have to finish the whole thing and get it working. My suspicion is it should be quieter on 3 phase power than the stock single phase E50. I can confirm that the Steinmetz connection is not a great idea with this motor.
I know that thread.
Ok for the frequency, but how do you insure the stability of the voltage ?
It is necessary with an induction motor.
This is the one I did years ago. Some of the transitors were because I had a surplus. 2N5401/551 should work in place of these with different pin out. The 23 V is to a Papst motor on a Gyrodek. The 216 V to TD124 etc. Sorry I have lost the circuit. It shows 90% the whole story. The nonpolar caps protect the motor should the amplifer fail. Distortion is about 0.1%. I think 45 watts if a 0.75 degrees per watt heat sink. As the motor is a reactive load 45 watts is a realistic minimum. It will get very warm. The input filter is also voltage set. The 74HC4060 is able to drive the filter, that saves an op amp. I use the power amp as an active filter allso, it is a op amp in style.
One of the steps I'm trying to eliminate is heating the bushings. While one would think 200 degrees should not be an issue, I'm concerned that it's impossible to know for certain what the combustion point is of any old oil (not to mention contamination) that may still be in the bushings. In my case, there is simply no way to know if at some point over the decades, someone decided to open the motor and add oil - perhaps more than once. I'm just wondering if it might not be a variable, something that was not done when the turntable was built, that could be eliminated.
However, you do make a good point about being able to create a vacuum by heating an air tight canister. After all, that's how my wife cans vegetables from our garden each year. Whether it would be sufficient to accomplish the task, I don't know.
However, you do make a good point about being able to create a vacuum by heating an air tight canister. After all, that's how my wife cans vegetables from our garden each year. Whether it would be sufficient to accomplish the task, I don't know.
The motor current draw is constant and I've not had a problem with voltage regulation, that said I do have a schematic version where I have implemented voltage regulation - don't know how well it works however, it will be tested in the next one.
I've done it a number of times with different motor bushings, most of which have no history known to me. Others have done it countless times without having the bushings catch on fire. I'm relatively confident that the combustion temperature for these sorts of oils is well beyond 200 degrees F. You could use a solvent to clean out the bushings, but my understanding is that you may remove the carbon in the bushing which is an integral part of how the oil is stored and wicks through the bushing. This I am told ruins the bushing, this might be hearsay..
I am almost 100% confident that vacuum will not remove the old oil from the bushing, there should be nothing for it to act against, and the original lubricant will have turned to goo or worse.
If you are concerned I would just purchase proper new bushings from a reliable source like Simone Luchetti here: Thorens TD 124 E50 Thorens 135 121 184 Complete Motor Rebuild Kit Made in Italy | eBay
These are real sintered bronze bushings, and should work quite well given his attention to detail.
Kevin, what are you using for a heat source? My past mixed success with using this process on other bushings might be related to not having the control I need. I may also need to work with a larger jar, greater volume of new oil. Thanks.
I use either my shop convection oven, my wife's (!) toaster oven in the kitchen when she isn't looking, or the gas oven. I lay them on a small cookie sheet (gas oven) or toaster oven tray with a little tin foil and more recently a single sheet of paper towel which helps to wick out the old oil once it starts to ooze.. No conflagrations yet.. 
I set the thermostat to 200 degrees F and let the oven warm up first, then after a few minutes I put the bushings in the oven for about 20 minutes.. I then remove them and pat them down a bit, then back in for a further 10 minutes. This seems to be quite effective.
I heat the oil in a small glass jar in near boiling water, or horrors microwave it. (Not recommended at home folks! I like excitement.. LOL) I use enough oil to make sure that the bushings are fully submerged in hot oil, arguably more is better, but I hate wasting oil, and I consider it spent once the bearings are done. The clue that the oil is ready for the bushings is when 20 wt flows almost like water. Leave in until cool. Install with freshly oiled felts. (Sopping) Wipe up all excess oil that oozes out after you have installed the bearing housings.
No question my MKII is much happier. I did clean and lubricate all the rotating components in the drive train and turned the belt inside out and talc'd the living daylights out of it - rubbing the talc into the belt as much as possible and then dusting it off so that it just looks discolored. Table is running very quietly now.
I set the thermostat to 200 degrees F and let the oven warm up first, then after a few minutes I put the bushings in the oven for about 20 minutes.. I then remove them and pat them down a bit, then back in for a further 10 minutes. This seems to be quite effective.
I heat the oil in a small glass jar in near boiling water, or horrors microwave it. (Not recommended at home folks! I like excitement.. LOL) I use enough oil to make sure that the bushings are fully submerged in hot oil, arguably more is better, but I hate wasting oil, and I consider it spent once the bearings are done. The clue that the oil is ready for the bushings is when 20 wt flows almost like water. Leave in until cool. Install with freshly oiled felts. (Sopping) Wipe up all excess oil that oozes out after you have installed the bearing housings.
No question my MKII is much happier. I did clean and lubricate all the rotating components in the drive train and turned the belt inside out and talc'd the living daylights out of it - rubbing the talc into the belt as much as possible and then dusting it off so that it just looks discolored. Table is running very quietly now.
Ok, that's very helpful. The first part, removing old oil is much the same as what I've done, but the question's been temp. I've been reluctant to use the big convection oven, but it will go down to 180, has a digital thermostat my wife says is very accurate, so I guess I'll wait until she's gone for a few days!
The second part of your process, putting the jar inside near boiling pot of water is new to me, but I can see the benefits. I'll have to give that a try. thanks!
The second part of your process, putting the jar inside near boiling pot of water is new to me, but I can see the benefits. I'll have to give that a try. thanks!
I use either my shop convection oven, my wife's (!) toaster oven in the kitchen when she isn't looking, or the gas oven. I lay then on a cookie pan with a little tin foil and more recently a single sheet of paper towel which helps to wick out the old oil once it starts to ooze.. No conflagrations yet..
I set the thermostat to 200 degrees F and let the oven warm up first, then after a few minutes I put the bushings in the oven for about 20 minutes.. I then remove them and pat them down a bit, then back in for a further 10 minutes. This seems to be quite effective.
I heat the oil in a small glass jar in near boiling water, or horrors microwave it. (Not recommended at home folks! I like excitement.. LOL) I use enough oil to make sure that the bushings are fully submerged in hot oil, arguably more is better, but I hate wasting oil, and I consider it spent once the bearings are done. The clue that the oil is ready for the bushings is when 20 wt flows almost like water. Leave in until cool. Install with freshly oiled felts. (Sopping) Wipe up all excess oil that oozes out after you have installed the bearing housings.
No question my MKII is much happier. I did clean and lubricate all the rotating components in the drive train and turned the belt inside out and talc'd the living daylights out of it - rubbing the talc into the belt as much as possible and then dusting it off so that it just looks discolored. Table is running very quietly now.
With regard to the oil in jar technique, I fill the pot to a few cm with hot tap water and then place the jar in the pot, and then gently heat the pot on low heat. I think 150 - 160 degrees gets the oil flowing nicely. (The water will be hotter because of the thermal resistance of the glass jar.) I use gerber baby food jars, they are somewhat heat tolerant, just don't over do it!
Small beakers if you can get you hands on a few should work quite well as an alternative.
Small beakers if you can get you hands on a few should work quite well as an alternative.
Are you doing anything to raise the jar off the bottom of the pot? Do you use string or anything else to suspend the bushings in the hot oil?
The jar just sits directly in the pot with a couple of cm of water around it, the bottom of these jars are coined so only the edge makes contact with the bottom of the pan. I doubt it matters as I am not aiming for very high heat anyway. You don't want enough heat for the water to ever boil.
The bushings sit loose in the oil, if used you should use a paper clip or similar to differentiate between the bushings. I use a medical swab (six inch wood stick) to remove them from the oil when I am ready to install them.
Very simple and direct, I tend not to complicate things much unless they don't seem to work..
The bushings sit loose in the oil, if used you should use a paper clip or similar to differentiate between the bushings. I use a medical swab (six inch wood stick) to remove them from the oil when I am ready to install them.
Very simple and direct, I tend not to complicate things much unless they don't seem to work..