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150 Drops of Oil ?

5.6K views 33 replies 15 participants last post by  DaninVan  
#1 ·
The label on the saw motor is to use 150 drops of oil. Who counts 150 drops of oil ? I gave it about a 10 small squirts.




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#2 ·
You've got a thirsty motor. I've been refurbing a couple Westinghouse fractional motors and each of them calls for 30 drops of oil per year if in regular use, every two years if use is occasional. Estimating the total, I applied the oil with a small tube that I dipped in the container and sealed the other end with my thumb.

Like you, I doubt anyone diligently counts drops.
 
#4 ·
You've got a thirsty motor. I've been refurbing a couple Westinghouse fractional motors and each of them calls for 30 drops of oil per year if in regular use, every two years if use is occasional. Estimating the total, I applied the oil with a small tube that I dipped in the container and sealed the other end with my thumb.

Like you, I doubt anyone diligently counts drops.
don't bet on it...

it's an oil impregnated bushing...
serious manufacturing cost saver and if ignored the demise of the motor is at hand...
the principle behind drops over squirts of oil is to give the bushing a chance to adsorb the oil instead of just flowing by...
if at all possible add oil reservoirs to bushinged motors...
bushings tend to make motors light to medium duty...
this is something else to keep in mind when using/buying motors...
 
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#6 ·
counting drops....
a lot of oil applicators are already marked for drop counting so that you really don't have to ''count'' but the secret is slow application...
a pause or two is a good thing during the oiling...
too much oil will just be ejected internally or externally by the motor as though it were pumped out of the housing .....
don't mind the mess.. over oil...
over lubing a motor is bad for the seals FWTW....
 
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#8 ·
especially after they weld themselves to the shaft and ruin the housing...
 
#9 ·
Almost as bad as when equipment requires "ounces or grams" of grease. We've actually had to calibrate the grease guns to determine how much one shot of each type of grease is... a pain.

But all you have to do is smoke a large, critical (and very expensive) motor and you become very critical of over-lubricating. Or worse, mixing incompatible greases.

these little oil cups may work on your machine. Our old south bend lathe is covered in them!

Oil Cups | MSCDirect.com
 
#11 ·
just to be overwhelming....
 

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#10 · (Edited)
Grease-related Bearing Failures
There are several types of grease-related bearing failures:

Lubricant starvation - Occurs when the grease cavity is not packed with the proper amount of grease during bearing installation, when the bearing is not regreased at the appropriate interval with the proper amount, or when the oil is removed from the base of the grease by bearing overheating.

Grease incompatibility - Greases are made with different base compounds such as lithium or poly-urea. Not all greases are compatible with each other; therefore it is important to use the same grease or compatible substitute throughout the life of the bearing. This requires grease specification when a double shielded bearing is ordered so it will be compatible with the grease that will be added during regreasing activities.
The bearing, the grease cavity around the bearing, and the grease used during regreasing has to be compatible.

Wrong grease
- It is important to use the correct grease for the correct application. Some bearing designs and applications need only general purpose (GP) grease while others need extreme pressure grease (EP). Selecting or regreasing with the wrong grease can lead to premature bearing failure.

Over pressurization of the bearing shields
- When grease is added to a grease cavity, grease volume and cavity pressure increases. Damage can occur to the shield on a single or double shielded bearing during regreasing if the grease is added too fast or if the grease cavity is full with no escape path for the excess grease. When the motor is placed into service, the grease will thermally expand. If the grease cavity is full, thermal expansion can create damaging pressure on the bearing shields. In either case, the shields can be dislodged from the bearing or the outside shield can be pushed against the bearing cage by grease pressure, which can lead to a bearing failure (see Figures 7 and 8).

Inside of motor full of grease - If the grease cavity is full and regreasing continues, the excess grease can find its way between the inner bearing cap and the shaft and flow to the inside of the motor. This allows the grease to cover the end windings of the insulation system and can cause both winding insulation and bearing failures (see Figure 9).

Overheating due to excess grease
- The balls of a bearing act as tiny viscosity pumps which roll on a small amount of oil film between the balls and the race. Too much grease volume will cause the rolling elements to churn the grease, resulting in parasitic energy losses and high operating temperatures, which in turn increase risk of bearing failure.

Contamination of grease - Greases are the same as oils when it comes to contamination (water, dirt, fiber, gasket sealant, etc). The more contaminants that are in the grease the shorter the grease life and the greater the reduction of its lubrication properties.


Relubrication Volume
One of the more important and frequently botched components of the greasing strategy is relubrication volume. When asked how individuals determine the amount of grease to apply to a particular component, a common response is “however much it takes.” This is obviously not a precise method. There are many acceptable methods for estimating the appropriate relubrication volume. A common method is recommended by SKF, where grease replenishment volume is defined by the following equation:

Gp = 0.005 * D * B

where
Gp = grease replenishment amount (gm)
D = bearing outside diameter (mm)
B = total bearing width (mm)

This method generally provides positive results, but does not always take every factor into consideration. For example, it does not account for differences in bearing housings and application points. Instead, it assumes the grease is added at the optimum location. Also, it is not always possible to know the amount and condition of old grease in the housing at the time of reapplication. For these reasons, it may be advantageous to modify the calculated values with a condition-based approach. The most advanced condition-based technique is ultrasonic instrumentation, which optimizes the relubrication volume. By establishing a baseline value and determining a statistically appropriate limit, the volume of grease added can be optimized. It is the opinion of the author that this hybrid approach is the best method for arriving at the optimum relubrication volume rather than relying on calculated values or instrument feedback.
 
#13 ·
Stick,

For a lot of our consumers we now use vibration monitoring to determine greasing requirements. The machinery can pick up when the lubrication is less than perfect when we trend it, and we give it a shot of grease then re-test. Part of the whole shift from time based ----> condition based ----> predictive maintenance.

There still is a little bit of black magic in vibration analysis, but I have learned to trust it a lot more in the past few years. The key is LOTS of sampling. We analyze about 60% of our machines each month, or before and after maintenance. The guys don't always like lugging the monitor around, but they've begun to see the benefit.
 
#18 ·
Greetings all!
First time poster here and new member.

I'm I field service technician for a representative of a large international pump manufacturer. Just to add my $.02, a lot of grease lubricated motors actually have a port opposite the Zerk fitting that needs to be opened while greasing to allow the old grease to be purged and it also helps to prevent some of the issues with over greasing. It would normally be left open for a period while running to allow things to stabilize before being replaced. Before lubricating a motor, check to see if it has one of these ports. Sometimes they have a threaded plug that needs to be removed, sometimes they did and the technician "lost" it and sometimes the motor manufacturer has another method. Over greasing can be just as detrimental to a motor as under greasing if not done properly.

The motors I deal with range from 1/2 HP to 300 HP and larger. Most of the problems encountered in my day to day travels can be attributed to one thing... Failure to read that little book that ships with the equipment. It can amaze you what they put in there sometimes.

Regards,
Roger

P.S. This forum looks like it has some outstanding members and I look forward to learning a lot from you all.
 
#20 ·
Welcome Rodger...
what kind of woodworking are you into???
 
#23 ·
Doug,

Those are what are typically called Vertical Turbines. The motor is on top and the impellers are at the bottom connected by a lineshaft in a column as in your photos. There are usually multiple impellers in series in order to increase the pressure or flow requirements. The motor will have anti-rotation pawls to prevent rotating in reverse. It's a very bad thing to rotate backwards. The impellers would spin off the shaft and grind themselves into the bowl. The only thing to do then is lift the entire pump out of the can for repairs. As you have shown, that's not always an easy thing to do on a 45' pump. Fun times! 35 years and doing good. Just shows what can be done with proper maintenance and lubrication. It's not uncommon to run across a 50 year old pump that works like new. Unfortunately, it's also not uncommon to run across one that is 6 months old and trashed because no one took the time to learn about what they have.

Regards,
Roger
 
#24 ·
Hi Stick,

Currently I'm in the process of some exterior refurb work on my 100+ year old craftsman style house. The roof over the kitchen is a flat seam terne metal roof with box gutters. It evidently, was an addition at some point in time and needs some major rework at the moment. I'll be removing the box gutters and extending the rafter tails to match the other roofs of the house which actually brings up a question. Is it possible to use the router to cut the curves into the exposed 2X8 lumber rafter tails? The original ones have a scroll pattern cut into them. Don't really want to use a jig saw since the blade tends to wander and trying to put them up on my band saw table would probably just get me hurt! Any ideas on the best way to do this? I have a Bosch GOF 1300 ACE router. I don't have a lot of accessories yet but can get some if needed.

Thanks,
Roger
 
#25 ·
Hi Stick,

1. Is it possible to use the router to cut the curves into the exposed 2X8 lumber rafter tails? The original ones have a scroll pattern cut into them.

2. Don't really want to use a jig saw since the blade tends to wander

3. and trying to put them up on my band saw table would probably just get me hurt!

4. Any ideas on the best way to do this? I have a Bosch GOF 1300 ACE router. I don't have a lot of accessories yet but can get some if needed.

Thanks,
Roger
1. yes it is... kinda tough on the router bits...

2. this is where having a squared away jig saw will come to your rescue...
Bosch jigsaws are noted for not wandering and true 90° cutting...
I like the JS470.. did know there are over 300 different blades for these saws...
rough cut w/ the jigsaw and finish w/ the router if you like but I think you'll be able to get where you need to go w/ just the jigsaw w/ fine results...

3. there are reasons your brain tells you to watch out.. listen to it..
you don't feel safe.. back up...

4. get the jig saw and have at it...
 
#26 ·
Hey, Roger; welcome!
What Stick said.
Relax on the rafter tail project. I guarantee the originals are far from perfect. They're at least 8' up in the air and you're the last person that's going to see them up close (as you make them).
Any quality commercial duty jigsaw ...but we love Bosch. ...and a rasp to clean up the cuts if you really feel they need it. A bit of a sanding and Bob's your Uncle; on to the next one. Seriously. :)
 
#27 ·
Stick,
Bosch it is then. Just ordered a JS470eb.

Hi Dan,
I'm not stressed about the looks, they are after all just rafter tails.
After two weeks I'll never notice them again and If you saw the 1/4" of paint buildup on the originals, these will be better looking by far. My goal is to use these more or less for practice to work on my skills. If I can't make a smooth rafter tail how in the world will I ever be able to make doors or cabinetry? It's also a lot less expensive to practice on than hardwoods :)

Any recommendations on which blade to use?

Roger
 
#28 ·

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#30 · (Edited)
Hmm. Lets see... For light oil, 18 drops = 1 ml. Conservatively, 150 drops (that is what it says, not 120 drops) that would be 8.3 milliliters. But it says 20 weight oil... 3-In-ONE Motor oil is 20 SAE weight.

8.3 ml per year, 0.7 ml per month, 0.16 ml per week, 0.02ml a day. At 18 drops per ml, a drop would be 0.05 ml.

EDIT-- Something I learned from my father on electric motors was to use Turbine Oil. Is 20 SAE weight, but is rated higher in its lubrication qualities and heat rating. I pick mine up at an industrial bearing supply here, that also sells Baldor electric motors.
 
#31 ·
Greetings MAFoElffen,

Yep, Turbine oil is what we use in the Vertical Turbine Pump motors like in the photo. I have a five gallon jug on my vehicle right now of ISO 32.

BTW, Turbine Oil works great as an air tool lubricant for tools requiring oil. Turbine Oil doesn't break down or oxidize as easily as other oils. Supco also has a neat little 4 ounce bottle of Turbine Oil that has a long pull out tube for those hard to reach places.

Roger