Lathe Spindle Oil Filter

A friend of mine has installed a generic automotive filter on his truck transmission. He claims it filters out all the clutch wear particles. I don't think you can use a finer filter in series with the pump because they have excessive back pressure and would limit oil volume. I think finer filters need to be used as a bypass filter. This means a certain amount of oil is bled off and ran through the filter and then back to the tank. This same friend uses this technique and claims it will remove the black in his diesel oil. After several thousand miles, he claims the filter weighs 3 lbs more than a new filter (both full of oil).

chuck

.....snip

Can an automobile oil filter handle that flow? If so, don't most auto oil filters have a spring-loaded bypass valve just for that reason? You can get generic, remote-mounted oil filter kits at auto parts stores or off-road vehicle stores.

Dave Berryhill

Detroit Diesel's use to use a knife edged strainer before the fuel filter to remove larger particles of material. They don't use them anymore as far as I know. I thought of using one as a filter on my parts washer, but couldn't find one. We used to have to turn the knife edge every round of the engine room to removed particles from the strainer mesh. I don't remember how often we drained the housing to remove the particles that settled on the bottom. I believe that a strainer would probably be what one would want instead of an actual filter as the filter would probably clog up quite fast.

Just my two cents....

Dave Young

gradstdnt snipped-for-privacy@yahoo.com (gradstdnt) wrote in news: snipped-for-privacy@posting.google.com:

A little tougher to do maybe, but probably the best way would be to filter the oil on the return side, this way, a) the particulates aren't eating up your pump, and b) you don't have to worry about pressure/volume to your critical components. If possible, a return 'windage' type tray could be fab'd in the gearbox to catch the majority of the oil and direct it through a gravity type filter media.

The problem is that centrifugal pumps have relatively low delivery pressure and the flow is reduced as back pressure is increased. To put it simply, a filter will reduce, maybe stop, your oil flow. Your lathe has run for 30+ years. Why re-invent the wheel. Leave the system alone but change the oil regularly. How about every 10 years, whether it needs it or not? The cost of an oil filter will probably pay for 3 oil changes. If you still have the lathe in 40 years, email me and tell me I was wrong.

John

Exactly. Because there are no products of combustion with which to deal, and the volume of oil that is circulated is low, plus operating cycles are often low, with constant interruptions, so there's more than enough time for the oil to self clarify by settling. They've been building these slow speed devices that way for a long time with outstanding success. The odd oil change along the way is more than enough to keep them running as intended.

Harold

Hey Guys,

I've often wondered about using an automobile engine filter in the return line instead of the feed line. Protect the pump a bit too. Suppose you could mount it so that the returning oil could drip/dribble/run/pour down a pipe into the filter, and the "head" pressure alone would force it through the filter and spill into the sump. If the filter became plugged, or for some reason can't keep up with the flow, the oil would just overflow the pipe and into the sump. I have never tried this, so I don't know what length a pipe would have to be, but I would think not longer than a foot.

Take care.

Brian Laws>

|I'm in the final stages of putting back together my Clausing |Colchester 13" machine. I've cleaned off 30 years worth of overall use |and abuse. | |This machine has an oil tank holding about 2.5 gallons of spindle lube |underneath the headstock. A pump driven by the main drive motor |distrubutes oil to the spindle bearings as well as dumping oil on the |forward and reverse wet clutch and splash lubing the rest of the |gears. When I first opened up the headstock, everything was coated |with a fine black grime. My best guess is that this was clutch |material resulting in normal wear from years of use. Since the |machine has an oil pump, placing a filter on the output of the pump |seems like a good idea on keeping harmful particulates out of the |headstock. | |Any ideas on what might work. Micron size rating that would filter |abrasion from clutch use. The finer the filter the better but the |tradeoff is greater restriction resulting in lower flow rate. The |pump is a centrifugal impeller style putting out maybe 5 to 10 gpm |with fairly low working pressure as a best guess. I don't want to |kill my machine by cutting off the oil supply but I would also like to |keep the oil as clean as possible. | |Any experience in this arena is greatly appreciated.

No experience on this particular (no pun intended) matter. Remote automotive filter adapers are readily available. Most use a spin-on Ford filter. Best micron rating may be in the Mobil 1 filters, but I think a Wix or other good quality filter would be sufficient.

Rex in Fort Worth

My idea stemmed from the presence of an oil pump being in place. Just like a small engine, when you have an oil pump, the application of adding a filter becomes practical. I'm not worried about pump wear, as it is a simple fan impeller with generous clearances. I am worried about the main spindle bearings and the very tight tolerances they work under. As I said in my initial post, the internals didn't exactly look squeaky clean when I started tearing into it.

The complication arises in that this is not a positive displacement pump, thus low working pressure. This more than likely won't work too well when coupled with a filter, especially a low micron one. I agree that the way the sump and tank are set up that contaminants will have an opportunity to settle out. It is very possible that this machine didn't have it's oil changed as often as it should resulting in the condition I aquired it. A lot can happen in 30 years.

On the plus side things are cleaned up and it's remaining years it will be well cared for. I think my best direction at this time would be to keep things as they are. Thanks for everyone's input. I appreciate the different prespectives I received here.

No experience, but a guy I worked with had a motorcyle that had a different method of filtering the oil, it had a cup on the crank that spun, return oil was centrifuged in it to get the crud out and was then pumped to the bearings. Might be something you could use with that idea. The advantage is that there's no pressure drop, being located before the pump. On the other hand, your tank is large enough that everything should settle out before being pumped back through, particularly if the pump pickup is located properly.

Stan