[juanvaldez]

We have a great condition but old shaper and hobber machines (Barber Colman). Currently we are running small- 10" to large 20" ring gears of carbon steel. The machines have always run on cutting oil but we are trying to decide if it would be possible to switch over successfully to an emulsion type coolant (semi-synthetic) or fully synthetic. We have tried the idea successfully on cast iron parts and would like to see if there is anyone out there that has made this switch or know of someone who has on hardened steel. Thanks in advance! We are using Chemetall coolant products :idea:

[RICHARD ZASTROW]

Those machines were built to use oil. The coolant will more than likely infiltrate the lube system and cause bearing failures as well as worm/worm gear corrosion.

I'd be willing to bet you already have some cutting oil in the lube system.

IMHO use cutting oil.

Dick Z

[juanvaldez]

The encouraging situation that supports the idea to switch from cutting oil to a semi or fully synthetic is that we are already using a semi synth. in another Barber-Colman shaper, only cutting cast iron. This has been running with the Chemetall coolant product for about 5 months being used everyday, 2-3 shifts, 5 days-a-week. My concern with switching on our other shaper and hob machines is the hardness of the metal being cut, carbon steel. I just wanted to get someone else to support the idea w/ their experience... or shoot it down. A seminar I attended at MasterChemical in Toledo for machining fluids showed all kinds of reasons to switch: fewer dermatitus issues, longer tool life, and recyclability. We have several machinists in our plant trained 'old school' that are resisting the idea because this steel is harder and without cutting oil tools and/or parts will be damaged.

[Geof]

I am not surprised the 'old school' guys are resisting, they were probably brought up on the high sulfur stink like hell cutting oils and don't feel comfortable unless they are working in a cloud of smoke and oil mist.

It is possible you could get better tool life with an emulsion type coolant because you will get better cooling right at the cutting edge. If you do switch I suggest you go with a much richer mix than most manufacturers suggest. I find this works better on operations like tapping and broaching where the tool is moving slowly under lots of pressure, shaping and hobbing is similar in this respect.

[RICHARD ZASTROW]

I'm one of those smoke and mist guys. I do prefer using rich mixtures of semi-synthetic water based coolants IN THOSE MACHINES THAT ARE DESIGNED TO USE IT.

Those older gear cutting machines have a lot of bushed type bearings and worm wheels that can be easily corroded by water based coolants. I tried it. It didn't work.

BTW, high sulfur content cutting oil will corrode bronze parts as well. There are far better modern cutting oils made specifically for your application.

Maybe you'll be luckier than I. LOL

Dick Z

[juanvaldez]

Thanks for your help gentleman! Every bit of info I'm getting right now is being weighed into the decision. That's one thing positive about this ugly economy... all things are being looked at for efficiency of all kinds. I'm the safety guy at our shop and I actually worked production for 6 months in addition to my safety responsibilities (instead of being laid off). So, I have been able to see the machining end of things with new eyes. The shaping and hobbing part of our shop seems to be one of the worst areas, oil everywhere. If switching to a coolant improves the machinists world in this area of the shop AND doesn't kill the machine then I'm all over it!

[MikeZee]

Gear cutting and Hobbing - sulphur based oil is the only way to go - it's all about lubricity.

[ctate2000]

The Old Guys are right. Use the oil. The oils do not cool as well as the soluable products, true. However, they do not need to as they tend to reduce the volume of heat produced by providing better lubricity.

Even the most advanced gear proceses today will employ oil as the cutting fluid. The water based products will work but you will struggle to obtain the same finishes.

I agree that the older machines will be happier with the oil bath. I have yet to aee any of the auto makers use water based lubes in the crank case.

[RICHARD ZASTROW]

Or you could have us convert your B/C to high speed CNC and run it dry. LOL

Dick Z