Still working my way towards chambering a barrel.

The rotary union I bought has a rather small hole through it - 3/16". I didn't find it in the Deublin catalog because the part number had a typo in it when the listing was typed. With that corrected I was able to look it up. It is intended to be Mounted on the non-tool end of a spindle that rotates at up to 12,000 or so rpm to supply through the spindle coolant to tool tips like drills, reamers, etc. It was apparently designed to be used with water soluable oil coolant and is said to flow near 5 gallons a minute of that, though the supply pressure isn't mentioned and I'd think it would be quite high to get that flow through such a small hole. It has a 60 micron inline filter requirement which isn't a problem.

I used soluable oil on the mill, and in truth it works really well when one is cutting. Metal finish is excellent, the low viscosity allows it to flow like a fast river which, because of the fluid energy, blows chips away much better than heavier oils and with its low viscoisity (like water) it doesn't stick to cutters and then come loose to fly across the room unless the cutter is spinning really fast - I don't have an rpm number but I remember being really suprised at how well it behaved. It was clear to me that there is a reason it is used in nearly all industrial applications where coolant is used. Alas, it has water in it and it does what water based things tend to do - it grows algae and stinks after while. It would get under the mill vise and turned the mill table black with algae growth. It was a bitch to get off and evidence of it's use remains to this day.

On the mill I changed to cutting oil and didn't like that either. It stuck to the tool and splattered all over the place, wouldn't move fast enough to move chips out of the way, didn't want to flow back down the drain pipes fast enough to prevent table overflow, and surprisingly didn't give as nearly as good a surface finish as the soluable oil did. I changed to hydraulic fluid diluted half and half with Mineral Spirits. That worked after a fashion, sort of. It was better than having to remove the mill vise after each session to wipe down under it, and it moved chips out of the way, but finish wasn't nearly as good as with the water soluable oil.

On the lathe I only used cutting oil, and that only when I was threading or drilling both of which aren't done at high speeds, so it worked out just fine to use a good grade of pure cutting oil. I intend to fill the coolant tank that gets used for threading and drilling with 5 to 7 gallons of Oatly dark thread cutting oil. That stuff works quite well.

That then leaves the question of what to do when reaming chambers. I spent some time studying the situation and reading. Reaming will be done at 300 rpm or less, probably more like 150 rpm, which, with things an inch in diameter, shouldn't be flinging coolant all over the place. I think I need as much flow as one can push by the reamer pilot to agressively clear chips which it would seem is the main purpose of the coolant. At 150 rpm speeds the reamer isn't going to have over temp problems any more than a 1/2" drill would have at the same rpm - but chips would ruin the chamber finish if not delt with. I also think I have a chance to fit a dedicated reaming catch trough under the chuck/muzzle/reamer that would catch essentially all of what flows out of the barrel breech during reaming. The trough would have drain tube that takes the coolant back, past some screens, to a dedicated reservoir, thence through a suction screen, pump, discharge filter (that meets the 60 micron requirement), and back into the barrel - what did get on the lathe bed could be wiped up and wouldn't cause algae to grow under a mill vise like it did on the mill. This looks like a situation where I could make use of soluable oil.

So my question, what do those of you who use a muzzle flush use for coolant?

Thanks
Fitch

The question that come next is what to use for a coolant/chip flush fluid. I think chip flushing is probably the number one job since reaming is done at relatively low speed.

You might want to run a search on the boards.

IIRC there was a great post awhile back with nicely detailed photos and descriptions of a home made pumping system and I think it went into a little detail about fluid.

-Spencer

We use rapseedoil whitch is an 100% vegitable oil. The brand is called Biocut 20.
It is pumped tru the muzzle. We have a manualy regulated bypass valve, to prevent splattering.
The result is wery nice chambers fully finished from first a rougher, and then a finisher in about 1 - 2 min pr chamber.
Reamer lifetime, is better than 500 chambers using hss reamers, and better than 1500 chambers using carbide reamers.

The lifetime of the oil is better than 3years, and as it does not containe sulpher, it wouldn't ruin carbide reamers

Your on the right track. I use Rustlick 255R, my only problem is I run the coolant in the lathe sump (built into lathe bed) and it is extremely hard to keep oil out of it. If you use a catch like you were talking about (I do) you won't have to worry about cleaning the coolant up after every job. I am getting ready to clean my sump out and hook up an oil skimmer to try and keep the coolant cleaner for the next batch. I have had the same coolant in the machine for 2 years, while it doesn't smell or look bad it grows alot of bacteria in the sump mostly from the tramp oil that gets in it.

Thanks guys. Between these posts and doing the suggested search I think I'm in posssession of enough data to make a decision.

Fitch

I use Mobilmet 766 mixed with transmission fluid. The 766 is a newer replacement for Omega. I live in a fairly remote location and the "local" Mobil distributor had a great price and free delivery as long as they were dropping something else off locally.
http://www.mobil.com/USA-English/Lubes/PDS/GLXXENINDMOMobilmet_760.asp
http://www.metalfluids.com/products/Mobil_Mobilmet_766_...ma_Omega-397-23.html
The reason I got the 766 is my shop is small 22x22 and stuffed with machines and my bench is 4' from my lathe. I didn't want to smell like dark thread cutting oil every day. The dark oil cuts great chambers but the scent lingers forever. Dave Kiff suggested using the atf in the mix. You might talk to a few reamer manufacturers.

Rustlick 255R seems to be popular. I was going to buy some but Kiff didn't recommend it. I'm not saying it hasn't cut a ton of good chambers. Most water soluble oils are designed for cooling without rusting. It's also very spendy and hard to get around here.

The carbonator pump I use is one I bought from fleabay. It's a Procon vane pump and is very quiet. I've got a Teel backup gear pump that hasn't run yet. The noise level will be much higher with that one. I've got a 1/2 hp carbonator motor that is a direct mount with the pump. I got the Gretan video and he recommends a much larger pump. I haven't needed any more power yet. Another consideration is the pumps are rated for a certain viscosity and running outside the envelope will diminish the life of your system.

I forgott to mention that the reason we changed from mineral EP oils, was a lot of health problems as skinirritation, and stomac problens (frequent diarea) among the staff.

After changing to a pure vegitabile oil, all the health problems has disapeared, and toollife has improoved. The cost of the vegitabile oil is also lower, and the enviromental problems is highly reduced

quote:

Originally posted by gunmaker:
I use Mobilmet 766 mixed with transmission fluid.

Reading about the 700 series it looks like good stuff. I note that you added ATF. Was that to make it thinner so it would flow better?

I looked at the mobile.com web page you provided the link to. Looking at it, I see that 766 has a viscosity of around 36 @ 40C and 6 @ 100C which would be pretty thick for pumping through the 3/16" hole in my rotary union. 762, on the other hand, has a viscosity of 10@40C and 3@100C which is considerably thinner and should pump better through my small rotary union.

Reading about it on the page you provided the link to, I found the following:

"Mobilmet 762 is particularly suitable for drilling, deep hole drilling (less than 20 mm diameter), threading, tapping, parting-off and automatic lathe operations on small work pieces."

20mm is a bit over 3/4" and all the chambers I'd be doing will be smaller than that - so reading the WEB page It would seem like 762 is the one that would be most suitable based on their application description.

So I have to ask, is there a reason to choose 766 +ATF over running undiluted 762 right out of the can? I'm asking, I don't have an answer.

I'm very glad you pointed this oil out to me.

There are real advantages, at least for me, to using a cutting oil as opposed to a soluable oil:

First, I can use the same 10 gallon coolant tank I use with the low pressure coolant pump as a common reservoir. Pump the stuff out the low pressure nozzle when threading, parting, or doing other things besides chamber reaming that require a coolant. Add a second outlet pipe with strainer to supply the high pressure muzzle flush system.

Second, I don't have to fabricate a seperate catch trough to fit in the bed. I can just let the oil flow where it always did and drain into the regular coolant tank under the lathe.

Third, I don't have any of the corrosion issues assiciated with soluable oil. It won't camp out in crevases and grow black algae for example.

Fourth, I can probably make it work with things I have on hand.

I think I can get by with a half HP pump. 5gpm at 100 psi would be around 0.3 HP. Rounding up would say use a 1/2 HP motor. As a happy coincidence I happen to have an unemployed Baldor 1/2HP 1725rpm TEFC motor on the shelf. I also have an unemployed small gear pump. Coupling those together with some appropriate filtering and a pressure relief valve would get me up and running sooner than later. The gear pump may be a bit on the small side, but if it wears out I can replace it easily enough.

I'll go mull this over. The devil is usually in the details - so it pays to go think it through for a few days.

Thanks
Fitch

I can't remember why Kiff recommended adding ATF. I just took his advice.

I use an air quick coupler to connect to my rotary union and there's no pressure problem through the little hole in the male end. The 766 is the replacement for Omega which was their heaviest duty cutting oil with less stink. I did call the Mobil Tech line to ask for advice as well and they pointed me towards 766. The only time I get any pressure problems is when I forget to connect the quick coupler to the rotary union and my bypass is not set to bypass. The gauges bury the needle pretty quick. I haven't blown a hose yet. The hoses and fittings I use are push connect from McMaster. No hose clamps needed. Not too expensive when you figure you don't have to buy any clamps. My pressure drops pretty low when I'm chambering a big bore. You have to file the pilot screw head inline with the flutes on the reamer to get the oil to pass. Bigger reamers have bigger flutes and less pressure going through. The 22cal reamers have chips blasting out, the 35cal and up not so much. Some guys use a water filter from Home Depot. I'm not sure the water filter would have survived my oops. I made a magnetic filter with super magnets for the suction side. I also use the super magnets in the tray I made out of alum flashing that runs the oil directly into the drain in my chip pan. I try to not fill my chambering oil with the junk that's in my chip pan. Most of it has to go through my pump. Not sure if I would try vegan oil. I'm kind of partial to the real thing. It would be hard to convince me that Mazola is better. I would rather use lard oil. In fact, there's a little lard oil in the Mobilmet 766.

One more thing. I thought it was pretty funny that the guy at the hardware store called the little tiny package "super magnets". Until I got the skin on my finger pinched between 2 magnets the size of M&M's.

quote:

Originally posted by gunmaker:
One more thing. I thought it was pretty funny that the guy at the hardware store called the little tiny package "super magnets". Until I got the skin on my finger pinched between 2 magnets the size of M&M's.

I like the super magnet swarf trap idea as well. Ought to be able to make some sort of small aluminum tube with the super magnets in it to trap metal particles.

This is starting to sound like a plan.

Edited:

I found a possible relief valve here
Set for 100 psi or so that should allow me to use short pieces of rubber air hose with QC fittings for the connecting tubing.:

That valve won't work.

I'm working on a schematic and parts list. I'll post it here when I get it finalized.

Thanks Again
Fitch

I bought my valve from MSC. It's bronze and cost around $20. The nylon one looks like it's got similar specs. I got some good ideas from benchrest central forums.

Fitch

You may have already made up your mind but,
I use Mobilmet S-122. It has worked very good for me.

James

quote:

Originally posted by gunmaker:
I bought my valve from MSC. It's bronze and cost around $20. The nylon one looks like it's got similar specs. I got some good ideas from benchrest central forums.

Do you have a part number?

Thanks
Fitch

quote:

Originally posted by J Bennett:
Fitch

You may have already made up your mind but,
I use Mobilmet S-122. It has worked very good for me.

James

I'll look it up. I haven't bought anything yet - now is the best time to change my mind so I'm looking at all candidates that show up before I buy something.

Thanks
Fitch

quote:

Originally posted by jørgen:
We use rapseedoil whitch is an 100% vegitable oil. The brand is called Biocut 20.
It is pumped tru the muzzle. We have a manualy regulated bypass valve, to prevent splattering.
The result is wery nice chambers fully finished from first a rougher, and then a finisher in about 1 - 2 min pr chamber.
Reamer lifetime, is better than 500 chambers using hss reamers, and better than 1500 chambers using carbide reamers.

The lifetime of the oil is better than 3years, and as it does not containe sulpher, it wouldn't ruin carbide reamers

Very interesting, Jørgen! Is the Biocut made for the industy, and were do you buy it?
Can Rapseedoil made for cocking be used in a pinch?

quote:

Originally posted by Bent Fossdal:

quote:

Originally posted by jørgen:
We use rapseedoil whitch is an 100% vegitable oil. The brand is called Biocut 20.
It is pumped tru the muzzle. We have a manualy regulated bypass valve, to prevent splattering.
The result is wery nice chambers fully finished from first a rougher, and then a finisher in about 1 - 2 min pr chamber.
Reamer lifetime, is better than 500 chambers using hss reamers, and better than 1500 chambers using carbide reamers.

The lifetime of the oil is better than 3years, and as it does not containe sulpher, it wouldn't ruin carbide reamers

Very interesting, Jørgen! Is the Biocut made for the industy, and were do you buy it?
Can Rapseedoil made for cocking be used in a pinch?

Hi Bent
The rapseed oil sold as Biocut, is an industrial oil, I know of 2 thiknes : Biocut 10, a thin versino, that we use for deephole drilling, and Biocut 20 that ve use for reaming, cutrifeling and chamber reaming. I know a lot of automatturning facilities who also use it on both (stangautomater?)massproduction short stroke lathes, and longturninglathes .


I dont know if rapseedoil for cooking wil last that long, because of its tendency for oxydation(guess it will harden like linseedoil)