cleaning and re-oiling sintered bronze bearings
I'm working on a different turntable at the moment, but as the subject of how to properly clean and re-oil sintered bronze has come up in this thread (as well as how to safely press new bushings into place). I thought I'd pass on this information, courtesy Lagermetall.
I'm including some of their text intended to explain how to safely machine the alloy, as it also speaks to what can happen if one were to buff sintered bronze and make it all nice n shiny!
I can speak to the effectiveness of using a heated oil bath to replenish oil. I've done it and watched as air bubbled out of the bushing. Nice to get the exact temperature from a knowledgable source though.
Lagermetall - Oljebrons
"The bearing surface of self-lubricating bearings must not be grinded as the oil transportation pores then will close. The outer surface of the bearing can, however, be machined in any way required. If external additional lubrication is used then even the pores on the outside diameter must be kept open.
The bearing can be heated on an electrical hot plate after machining to check that the pores are still open. Oil will then ooze out of the bearing.
Bearings usually lose oil during the turning operation and the lost oil should be replaced before the bearing is used again.
A simple method of doing this is by immersing the bearing in oil SAE 20, heated up to 80° C. (176 degrees f.) The bearing should be immersed until the oil has cooled off.The pores are filled with oil by this process and the bearing is once again ready for use.
Assembly
The sintered bearings are porous and can be damaged if fitting is not carried out correctly. Assembly by hammer blows deforms the bearing. The correct method is by using a shouldered insertion pin.
When the recommended interference between housing and bearing (H7/r7) is used the shrinkage of the inner diameter will be 0,5-0,6 times the interference.
Fitting without the use of an insertion pin can only be done where a tolerance of more than IT8 is acceptable on the fitted bearing.
Insertion force required per mm 2 of outside surface area:
ESSEM Oil-bronze - approx. 3N
ESSEM Graphite-bronze - approx. 2N
ESSEM Ferro-bronze - approx. 5N"
I'm working on a different turntable at the moment, but as the subject of how to properly clean and re-oil sintered bronze has come up in this thread (as well as how to safely press new bushings into place). I thought I'd pass on this information, courtesy Lagermetall.
I'm including some of their text intended to explain how to safely machine the alloy, as it also speaks to what can happen if one were to buff sintered bronze and make it all nice n shiny!
I can speak to the effectiveness of using a heated oil bath to replenish oil. I've done it and watched as air bubbled out of the bushing. Nice to get the exact temperature from a knowledgable source though.
Lagermetall - Oljebrons
"The bearing surface of self-lubricating bearings must not be grinded as the oil transportation pores then will close. The outer surface of the bearing can, however, be machined in any way required. If external additional lubrication is used then even the pores on the outside diameter must be kept open.
The bearing can be heated on an electrical hot plate after machining to check that the pores are still open. Oil will then ooze out of the bearing.
Bearings usually lose oil during the turning operation and the lost oil should be replaced before the bearing is used again.
A simple method of doing this is by immersing the bearing in oil SAE 20, heated up to 80° C. (176 degrees f.) The bearing should be immersed until the oil has cooled off.The pores are filled with oil by this process and the bearing is once again ready for use.
Assembly
The sintered bearings are porous and can be damaged if fitting is not carried out correctly. Assembly by hammer blows deforms the bearing. The correct method is by using a shouldered insertion pin.
When the recommended interference between housing and bearing (H7/r7) is used the shrinkage of the inner diameter will be 0,5-0,6 times the interference.
Fitting without the use of an insertion pin can only be done where a tolerance of more than IT8 is acceptable on the fitted bearing.
Insertion force required per mm 2 of outside surface area:
ESSEM Oil-bronze - approx. 3N
ESSEM Graphite-bronze - approx. 2N
ESSEM Ferro-bronze - approx. 5N"
I wouldn't have expected any less from you! Your miles ahead of me on all of this. I was just happy to have a target temp to work with!
I asked a lot of questions and read a lot. One of my closest friends although an EE also happens to be one hell of a machinist so I asked him for his take on things and he made me a couple of little tools to make things easier.
I was just asked to refurbish another TD-124 which I will be taking on this fall. I think this will be the seventh one I have directly worked on. Loosing count.. lol
I was just asked to refurbish another TD-124 which I will be taking on this fall. I think this will be the seventh one I have directly worked on. Loosing count.. lol
Tools? You have tools? ;-) OK, I have special tools . . . two shot glasses - one for heating oil, one for heating me . . .and I try real hard not to get them confused.
Hello Kevinkr,
Can you post some pictures of a shouldered insertion pin? I've replace a pair of bushings on my 124 bearing housing using a bench vise and some wood. While I was turning the vise the bearing started to go in at an angle. I straightened it and continued. The spindle seems to run smooth, but I am still concerned that I may have distored the bearing. I don't want to run the spindle in this housing for fear of damaging it. I have an old spare bearing assembly that I am using now. So, should I just press out these bearings and install new ones the "correct way?"
Regards,
David
Can you post some pictures of a shouldered insertion pin? I've replace a pair of bushings on my 124 bearing housing using a bench vise and some wood. While I was turning the vise the bearing started to go in at an angle. I straightened it and continued. The spindle seems to run smooth, but I am still concerned that I may have distored the bearing. I don't want to run the spindle in this housing for fear of damaging it. I have an old spare bearing assembly that I am using now. So, should I just press out these bearings and install new ones the "correct way?"
Regards,
David
I suspect careful visual inspection would reveal whether or not you have damaged the bushing. I would expect if the shaft turns freely that the bearing may be OK. You could replace the bushings if that made you more comfortable.
The picture of the tool already resides somewhere on this thread. I can repost at some point if you don't find it.
You can make one easily with a hardwood dowel if you have access to a wood workers lathe. Ideally you would first turn the dowel to a few thousandth less than the OD of the bushing and then turn a step of about 1.0" length to the ID of the bushing. I usually push them in by hand, whatever you do never use a hammer even on the dowel.
The picture of the tool already resides somewhere on this thread. I can repost at some point if you don't find it.
You can make one easily with a hardwood dowel if you have access to a wood workers lathe. Ideally you would first turn the dowel to a few thousandth less than the OD of the bushing and then turn a step of about 1.0" length to the ID of the bushing. I usually push them in by hand, whatever you do never use a hammer even on the dowel.
Thanks for confirming...figured this was the case. This table is like a blossom opening its petals
It starts with me noticing a new passage of music on a record I had played many times before which gives way to the airy and extended highs of a string section or an electric piano hanging suspended for a moment. The solidity of bass and overall quality of refinement I heard so much about is coming to the fore with each revolution and each day, with no other changes to my system save a little 20wt oil with some cleaning and adjustment. What started as hard and compressed is now open and effortless.
It starts with me noticing a new passage of music on a record I had played many times before which gives way to the airy and extended highs of a string section or an electric piano hanging suspended for a moment. The solidity of bass and overall quality of refinement I heard so much about is coming to the fore with each revolution and each day, with no other changes to my system save a little 20wt oil with some cleaning and adjustment. What started as hard and compressed is now open and effortless.
Sounds like you are moving in the right direction, this is how I would describe both of mine, of course it is the combination of arms and cartridges with the table, but the only other one I've liked nearly as much was a Garrard 301 also with a Schick arm and a now forgotten but very good LOMC.
batsong - KCMO here. OK, kevinkr and everyone else . . . I'm about at a point where coming up with something respectable (inexpensive) in the way of a cartridge for the TP-14 tonearm has to be determined, so I'm open to suggestions.
This is a TD-124/II with the iron sub-platter (as confirmed by my highly scientific "if a refrigerator magnet sticks to it" test).
So far, the cartridges that have been recommended are the Denon DL103 or DL103R, and the Nagoka MP11 Boron (I know, not made anymore).
I'm leaning toward MM, simply because I've only got one preamp that will do MC and adding that to the magnetic sub-platter, just seems staying with MM for the time being makes the most sense. But I'm open to all suggestions.
Oh and anybody just sitting on a spare finger lift, let me know. That and the Thorens badge are MIA on my headshell.
This is a TD-124/II with the iron sub-platter (as confirmed by my highly scientific "if a refrigerator magnet sticks to it" test).
So far, the cartridges that have been recommended are the Denon DL103 or DL103R, and the Nagoka MP11 Boron (I know, not made anymore).
I'm leaning toward MM, simply because I've only got one preamp that will do MC and adding that to the magnetic sub-platter, just seems staying with MM for the time being makes the most sense. But I'm open to all suggestions.
Oh and anybody just sitting on a spare finger lift, let me know. That and the Thorens badge are MIA on my headshell.
I think the DL-103 in a proper body is still the hottest reasonably priced option you have. I have a cast iron platter on my TD-124/II and have used at least 5 different SPUs (soon to be a sixth) on it without difficulty as well as a ZU DL-103 and a Denon DL-103D.. I'd also look for a used DL-103SA which is pretty rare now.
A set of transformers like the Partridge 977 will provide enough gain and are a great match for a DL-103 and run you about $150.. Good sounding as well..
A set of transformers like the Partridge 977 will provide enough gain and are a great match for a DL-103 and run you about $150.. Good sounding as well..
You can purchase a number of different bodies which make a remarkable improvement to the performance of this cartridge.
The other option is to just purchase a new or lightly used ZU Denon DL-103: http://www.zuaudio.com/turntable-cartridge.php I purchased a very lightly used Grade 1 for very reasonable money, up to that point it was the best cartridge I had ever heard, and clobbers a stock DL-103 in direct comparison.
Something like this in wood:
Denon DL 103 Exotic Wood Cartridge Body Upgrade Thorens Micro Seiki McIntosh | eBay
or
Club Wood Denon DL 103 Mpingo Wood Upgrade | eBay
There is also a seller of nice metal housings over at Lenco Heaven last time I checked.
Note that these all require you to carefully remove the existing body, there are a number of good places to find out how to do this including here: http://www.youtube.com/watch?v=-ENq8PoXhaU (Courtesy of Thomas Schick)
I have my suspicions that at least one very expensive LOMC cartridge in an aluminum housing with a spherical stylus and a suspiciously familiar generator assembly is in fact a repackaged DL-103.. What I am saying is it has good roots..
Even diying a used good cartridge into a good body is going to pay off as long as you don't break it in the process.
The other option is to just purchase a new or lightly used ZU Denon DL-103: http://www.zuaudio.com/turntable-cartridge.php I purchased a very lightly used Grade 1 for very reasonable money, up to that point it was the best cartridge I had ever heard, and clobbers a stock DL-103 in direct comparison.
Something like this in wood:
Denon DL 103 Exotic Wood Cartridge Body Upgrade Thorens Micro Seiki McIntosh | eBay
or
Club Wood Denon DL 103 Mpingo Wood Upgrade | eBay
There is also a seller of nice metal housings over at Lenco Heaven last time I checked.
Note that these all require you to carefully remove the existing body, there are a number of good places to find out how to do this including here: http://www.youtube.com/watch?v=-ENq8PoXhaU (Courtesy of Thomas Schick)
I have my suspicions that at least one very expensive LOMC cartridge in an aluminum housing with a spherical stylus and a suspiciously familiar generator assembly is in fact a repackaged DL-103.. What I am saying is it has good roots..
Even diying a used good cartridge into a good body is going to pay off as long as you don't break it in the process.
OK, thanks for the info. Modding this cartridge is something I've not read about before. I can see the advantage. Reminds me a bit, though, of the Shure V15/III and the "DU" version that shipped with many Duals. I've got one of both flavors, so it was easy to spot that other than markings, the "DU" version is different only in that it's sans the chrome painted plastic body.