[gtiworks]

Before turning on my Industrial Hobbies Mill which is in the last stages of being converted to CNC, I decided to open the mill head to check for grit/dirt in the oil. When I opened the mill head, it looked like all the gears were rusted, but what I found was a sticky, brown gooey sludge covering all the surfaces.

After several hours of work with paper towels and brake cleaner, I finally cleaned out all the sticky brown goo. This is a new and never run mill. Check your mill.

[ckindon]

Cosmoline? Often used to coat metal parts (especially sea-faring ones) to prevent rust.

[Cruiser]

Most likely it is fine cast iron left over from the machining process at the manufacture site. They apparently don't have a cleaning process between the machine and assembly process. I have cut lots of cast iron in my yrs at a large production shop and know that the fine has an affinity for itself and will stick especially when a sticky coolant is pressent. The best and only bet to rid yourself of it is to dissassemble your gear box and clean the inside with a pressure washer, there are some spots down in the bottom where you just can not reach. Also, the same problem can exist within the quil as both the quil and spindle are machined of cast iron so take it apart too then regrease and assemble. Any left over iron fine will circulate through the gears and bearings. Although the gears can tollerate and eat a lot of this fine without complaint, the bearings will surely fail in short order. Don't trust your cleanup ! take it apart and blast it clean, if necessary take it to a car wash and use the wand !

[underthetire]

Cosmoline? Often used to coat metal parts (especially sea-faring ones) to prevent rust.

I agree
Most machines have this crap all over them. Kerosene/diesel works great to remove it.

[ksanalytical]

I turned my empty head on its side and sprayed it out with carb cleaner. Seemed to work real well. I also added some magnets inside to catch anything that gets close to them and hold it out of the gears.

In the quill, I had to use a long shaft electric die grinder ($35 from Harbor Freight to grind all the rough stuff out. No amount of scrubbing with a wire brush in the solvent bath would get all the loose stuff out. Every time I though I had it clean, more would come out when I rubbed a paper towel through it.

I'm converting to AC bearings and I definitely didn't want $120 in new parts chewed up by loose iron bits.

Ken

[jetflatline]

One of my first learning experiences was putting magnets in the filter on a VW bug engine. Since then, it's almost a religion with steel gearboxes that I open up.

[HorridHenry]

Don't trust your cleanup ! take it apart and blast it clean, if necessary take it to a car wash and use the wand !

An overnight soak in petrol/gasoline will work wonders,damn never heard of water for cleaning metal parts before....you live and learn.

Looks like heavy grease mixed with metal wear fatigue.

[gtiworks]

Thanks all for the responses.

I checked the brown goo with a strong magnet and it is filled with very fine iron particles. I'll now disassemble the gearbox and do a through cleaning. Those fine iron particles would eventually do major damage to the gears.

[Cruiser]

Thanks all for the responses.

I checked the brown goo with a strong magnet and it is filled with very fine iron particles. I'll now disassemble the gearbox and do a through cleaning. Those fine iron particles would eventually do major damage to the gears.

Its not the gears you have to worry about. The gears are much harder than the iron fine and can eat a lot of it without damage. It is the bearings that can not tolerate the fine as it will hang and stall the bearings and they skate and burn up in a heart beat !
Take it to the car wash if you don't have some high pressure system at home or work. Just make sure that you dry it well as soon as possible, compressed air works good and a hot air gun will get the water out of pores. Then just oil the iron. These are sand mold iron castings and will have a very rough texture to the touch and the rough surface and the cavities will hold fine in a state of adhesion but running is swirling oil it will release and circulate through the bearings. It is imperative that it gets the clean out that should have been done at factory between machining and assembly but never did because the factory will not do what it can get away with undone !
I have machined tons of iron in my years as a machinist and know that the fine and free graphite will adhere to the base iron like a nasty little gremlin.
The dark stain on your paper towel is FREE GRAPHITE ! and isn't your worry like the iron particulates are.

I have been preaching this for a very long time, nobody hears me tho ! Then they come back and cry that their bearings are all wasted ! Don't be one of those !

[Cruiser]

An overnight soak in petrol/gasoline will work wonders,damn never heard of water for cleaning metal parts before....you live and learn.

Looks like heavy grease mixed with metal wear fatigue.

When I worked at a large shop, we used a hot water pressure wash to clean nearly everything. Then we would give it a blast of air to blow off the loose water and let it dry. Then we gave them a spray of CRC56 for protection. WE tried Wd40 and it does not work worth a damned ! EXCEPT for killing yellow jackets and starting fires !

[LUCKY13]

You would be surprized just how good something like good ole Dawn dish washing detergent works. Dawn does better than the other soaps and it washes out good to.


Then using heat either a blow drier, or hot air gun will get it dry. A space heater works good and doesnt take as long if you have such. But you must get it dry.



Jess

[gtiworks]

Brown goo removed. I washed down the milling head gearbox with lots of brake cleaner and then a thorough washing with soapy high pressure water. I used dish washing soap and it came out very clean. I reassembled the gearbox, added gear oil, and it all moves smoothly. Thanks to all for the helpful suggestions

[henryarnold]

I'm rebuilding my Grizzly G0519 Dovetail Column Mill which has a gearbox similar to the IH Mill and I also found brown sludge in my gearbox. I cleaned the gearbox out and I am replacing all the bearings.

I'm documenting the process here:
http://www.metalworkingfun.com/showt...d=3417#pid3417

[gtiworks]

To my surprise, all the bearings in my mill head gearbox were shielded on both sides and thus were not exposed to the particle contaminated brown goo. I would have thought that the bearings would have been open and exposed to the lubricating gear oil. Since the shielded bearings turned smoothly with no hint of particle contamination, I did not replace them.

Are shielded bearings normal in these mill heads?

[henryarnold]

My bearings were shielded but I decided to replace them anyway. I wasn't sure what the sludge was and whether it could get inside the bearings.

[DarkStarMedia]

I turned my empty head on its side and sprayed it out with carb cleaner. Seemed to work real well. I also added some magnets inside to catch anything that gets close to them and hold it out of the gears.

In the quill, I had to use a long shaft electric die grinder ($35 from Harbor Freight to grind all the rough stuff out. No amount of scrubbing with a wire brush in the solvent bath would get all the loose stuff out. Every time I though I had it clean, more would come out when I rubbed a paper towel through it.

I'm converting to AC bearings and I definitely didn't want $120 in new parts chewed up by loose iron bits.

Ken

Which ones did you use? I will be swapping out to the 30 taper spindle and I cant seem to find the thread that has the part numbers and the instructions... I remember seeing it somewhere...

Richard

[ksanalytical]

The part numbers are 7206 and 7207. I got SKF brand, but many have had good luck with cheaper stuff. I haven't actually gotten around to installing them as the spindle and quill will require some grinding to get the proper fit. It's critical that the bearings are not a press fit as that would make it nearly impossible to properly set the preload.

Ken

[DarkStarMedia]

The part numbers are 7206 and 7207. I got SKF brand, but many have had good luck with cheaper stuff. I haven't actually gotten around to installing them as the spindle and quill will require some grinding to get the proper fit. It's critical that the bearings are not a press fit as that would make it nearly impossible to properly set the preload.

Ken

according to SKF you need an interference fit...

"
Angular contact ball bearings are
usually mounted with an interference
fit onto the shaft.
"
http://www.skf.com/files/264272.pdf

pg 16

Richard