This may beat the cow head...

Now I know why I do so much better than my competitors sometimes... Just got a call from a potential customer who wants to drill .250" holes in
radiation hardened 316l stainless while spraying the unit with mercury... 1" thick stainless with no coolant.
Sounds like a prank call at first, but turns out to be a nuke application. All my competitors turned him away. Wonder why. :)
If the drill "bit" breaks, they close the door, destroy the whole container and start over with a new unit from me.
I'm guessing that I need to run at 50 RPM or less. Any thoughts?
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
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I don't understand this. Spraying what unit with mercury?
And how hard is "radiation hardened" 316L?

?????????
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Remove "nospam" to get to me.

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Joe, it sounds like you'll be using the mercury as a "coolant", right? I suspect it doesn't have much in the way of lubrication qualities, but I'm not sure. If you'll be using a conventional style of drill, you might want to get a Rockwell C hardness for the material. If it's below 35RC, you might be fine with a cobalt screw machine length bit.
If the material is harder, or if drill life is paramount (and it sounds like it is), perhaps you should talk to MA Ford about their "Twister XD" series of carbide drills. I've used them in 316L and Invar, and like them a lot. Ask for speed/feed recommendations, or you can try their S/F chart for starters:
http://www.maford.com/SpeedFeed.htm
No affiliation, just a happy user.
Wud
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316L stainless and mercury seems to be the Spallation Neutron Source; are these guys from Oak Ridge?
Though http://www.ornl.gov/~webworks/cppr/y2001/rpt/109853.pdf suggests the geometry is 1-inch ID tubes with 1/16" walls - or perhaps that was the prototype.
Tom
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wrote:

I can't say where they are from and where they are not from... Because if I say they are not from XXXX now and later simply say that I can't confirm that they are from XXXX, then I've basically confirmed where they are from, eh? Cheerios anyone?
We have a verbal NDA of sorts where they know I am going to look into the details publicly (here, elsewhere) for tips on the process, but that I won't ID them as an agency/facility/entity/whatever. All I can say is that they have a .GOV or similar web presence so it's not some yahoo in a banned country, etc..
We got the order for one test unit... I'll have some feedback from them soon I hope. I just won't accept returns or items needing service. :)
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
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Joe AutoDrill wrote:

Why not Joe? I'd think "Glow in the Dark" managemant would set you apart from your competition! LOL You'd also be a real hit at parties and such.
--

John R. Carroll
www.machiningsolution.com
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We have a "no flashing" rule in the office.
--


Regards,
Joe Agro, Jr.
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On Thu, 28 Feb 2008 17:39:48 GMT, "Joe AutoDrill"

<snip> =========After reading all the responses, I have to ask if conventional machining is the best solution, given the apparent very high value of the units, toxic environment, and ultra hard material.
What about some form of laser drilling, chemical or electro chemical milling or tap disintegrator/hole shooter? It won't be as fast, but then the cost of a broken tool bit and loss of a unit appears to justify a very slow process.
Without seeing the unit, I envision some sort of dam around the tube to allow horizontal positioning, possibly made from rtv, and stuck on the tube with rtv, with continuous flushing/filteration and recycling, to cover the disintegrator or electrochemical anode. A bottom drain on the dam would allow any leaking mercury to be trapped in the bottom of the fluid recirculation sump and get it out of the way of the cutting tooling.
Good luck, and I hope you are not one of our "glow in the dark" contributors after this project.
Unka' George [George McDuffee] ------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
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But.... We don't offer laser, chemical or electro-chemical options... <G>

Vertical drilling - from below the part...
In other words, imagine a radiation hardened stainless bucket full of mercury... You can't use coolant and have to drill a hole in the bucket to vent the mercury (possibly under pressure?!?) out the hole. When your drill breaks through, you can therefore expect the mercury and anything else in there in the form of liquid or gas to spray out the flutes of teh drill and/or hole and all over your machine. Not only that, but the stainless is four times the thickness of your drill's diameter...
So... I'm guessing the entire area that your machine (er... my machine?) is in as well as the area surrounding the work area is totally sealed and recirculated somehow.
I don't know how they plan on capturing the mercury, chips, radiation-tainted "stuff" all over the place, etc. but that's their part of the project. My part is making sure the drill can perform the process with no problems...
Here is my take on it... The biggest worries I have are (in no particular order):
1. Radiation's effect on my unit's seals, etc. It can't stroke and crete thrust for drilling if the seals disintegrate...
2. Radiation's effect on the air motor components, tubing, etc.
3. Mercury contamination of whatever... I have no clue what it will do if it pools in my unit's bearing surfaces and somehow makes it past selaed bearing surfaces and into the bearings, inner workings of the unit, etc.
4. That they may actually send the thing back to me at some point for some reason... I'll be scribing the serial number into every part and looking for them in the future...

What makes you think I'm not already glow in the dark, eh?
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com
V8013-R
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