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View Full Version : Installing a grease nipple on a curves surface ?



TR
07-26-2014, 06:55 AM
I have replace the backgear assembly on my turret mill. The mill is about 30 years old, still in excellent condition. I see there is no external to way to grease
the back gear assembly. I want to install one grease nipple on the curved surface so it directly greases the bull gear. This should be adequate and it will ensure the grease
actually targets the gears.

Should I use an end mill and machine the surface flat and then drill and tap ? Or maybe just use a long grease nipple and have some of it protruding ? The material to drill is about 15mm thick.

http://i663.photobucket.com/albums/uu354/topari/DSCN5056Small_zpsed0254ee.jpg (http://s663.photobucket.com/user/topari/media/DSCN5056Small_zpsed0254ee.jpg.html)

http://i663.photobucket.com/albums/uu354/topari/DSCN5055Small_zps3ed6abca.jpg (http://s663.photobucket.com/user/topari/media/DSCN5055Small_zps3ed6abca.jpg.html)

boslab
07-26-2014, 06:58 AM
Spotface cutter or counterbore will produce a small circular flat for the nipple to sit on
Mark

Mike279
07-26-2014, 08:08 AM
I would drill a small hole in a scrap block to use as a drill guide. Position the block and it will keep the drill from wandering until it can get started. Drill to size and tap for grease nipple. Mike

PixMan
07-26-2014, 08:45 AM
The machine is 30 years old and still in good condition, yet you want to "improve" it's lubrication system? Sounds like a solution in search of a problem.

I have to wonder why there wasn't a fitting there in the first place. Is it possible that it's a sealed area to keep original lube (if any) in there and contaminates out?

TR
07-26-2014, 08:54 AM
Good condition, but for the worn out back gear assembly. It looks like the gears ran dry for years. According to the schematics, it is not a sealed area. A bit of regular grease should keep the gears smooth and quiet for years.

My plan for the grease nipple is to use a two flutted end mill and machine out a flat spot, then drill and tap.

RichR
07-26-2014, 10:37 AM
Good condition, but for the worn out back gear assembly. It looks like the gears ran dry for years. According to the schematics, it is not a sealed area. A bit of regular grease should keep the gears smooth and quiet for years.

My plan for the grease nipple is to use a two flutted end mill and machine out a flat spot, then drill and tap.

You identified the problem, the gears ran dry. So why not just grease the gears and be done with it? I see a cavity with two gears in it. Add a grease fitting and
over time you'll just wind up packing the cavity with grease (and maybe overflow it). You can just as easily pack it by hand prior to reassembly.

KiddZimaHater
07-26-2014, 10:50 AM
You answered your own original question correctly.
Use an end mill to make a flat.
Then spot drill, drill, and tap.

LKeithR
07-26-2014, 12:34 PM
The thing may have lasted 30 years with out grease but it will do better with it. And you don't need to mess around with end mills and flat surfaces for the grease fitting. Use one with NPT threads and it seals on the thread, not on any mating surface...

PixMan
07-26-2014, 01:04 PM
You identified the problem, the gears ran dry. So why not just grease the gears and be done with it? I see a cavity with two gears in it. Add a grease fitting and
over time you'll just wind up packing the cavity with grease (and maybe overflow it). You can just as easily pack it by hand prior to reassembly.

I agree with this.

It lasted 30 years or so without grease, so let me ask how many of those you've had it, how many hours did it run and how long do you expect to use it? If it was bought for a commercial shop originally and got 20 to 60 hours a week for 15 years, and then you got it and used it 10 hours a month, a simple coating of a good open gear lube should make it last a near eternity.

Paul Alciatore
07-26-2014, 01:40 PM
From your photos it looks to me like you are going to have to pump an awful lot of grease into there to insure that just some of it actually jumps the gap and gets to the gears. Then, you are going to have to rotate the gears while greasing them to insure distribution around all the teeth. You are going to wind up overfilling the gear cavity. I would think you would need a grease tube that comes within a few thousandths of the gear teeth so the grease goes there and not all over. I would make that a small diameter tube so you do not apply excessive grease.

A thought: is this really designed for grease? Or perhaps an oil bath?

As for installing the grease fitting, I see no harm in having some space under it's flange, just use some thread locker to keep it in place. If you want a flat, you could just file one. Or use an abrasive wheel. I mean, we are not talking NASA specs here. A counterbore is a good idea too.

Jaakko Fagerlund
07-26-2014, 03:32 PM
Either make a flat with an end mill or just drill at the draft angle and be done with it.

andywander
07-26-2014, 03:45 PM
Many(if not most) grease fittings have tapered threads, and there is no need for the flange on the fitting to be tight against the casting.