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View Full Version : ?? Micro drilling stainless steel QUESTION??



mochinist
08-17-2001, 04:31 AM
<font face="Verdana, Arial" size="2">Originally posted by Rustybolt:
Tiny drills are made for drilling very thin materials.The next questiion would be; how do you center them? Almost any center drill is going to have a chisel point that is going to leave a flat an the bottom. No matter what the material you don't dare dwell at the bottom of the hole or the drill will instantly dull.You have to be careful of the coolant used so as not to accumulate chips and pack the hole and thus break the drill.
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Thanks for the lesson, now let me give you one. Center drills are for making centers in a part that needs to be held on a live or dead center. Spot drills are for centering your hole before you drill it. Here is some miniture spot drills that I have used in the past, http://www.harveytool.com/products/product_detail.php ?product_id=11400&category_id=1&product_family=Miniature+Spot+Drills (http://www.harveytool.com/products/product_detail.php?product_id=11400&category_id=1&product_family=Miniature+Spot+Drills)
I looked at the spot these make under a microscope and they hardly make a flat at all. I would make sure my part is indicated in nice and flat, and then set the spot drill to go in .002", that way the top of the hole would have a nice small chamfer.

As for not dwelling at the bottom of the hole, all I can say is duh. I also use the same coolant whether or not I drill .015" holes on the cnc or drilling 1" holes, I just set it to take such small pecks that chip packing isn't an issue.

As for the other stuff you said, yeah small drills aren't usually made for going that deep, and to be honest I would turn down that job if anyone ever brought it in to my shop.

[This message has been edited by mochinist (edited 08-17-2001).]

Rustybolt
08-17-2001, 08:17 PM
<font face="Verdana, Arial" size="2">Originally posted by mochinist:
Thanks for the lesson, now let me give you one. Center drills are for making centers in a part that needs to be held on a live or dead center. Spot drills are for centering your hole before you drill it. Here is some miniture spot drills that I have used in the past, http://www.harveytool.com/products/product_detail.php ?product_id=11400&category_id=1&product_family=Miniature+Spot+Drills (http://www.harveytool.com/products/product_detail.php?product_id=11400&category_id=1&product_family=Miniature+Spot+Drills)
I looked at the spot these make under a microscope and they hardly make a flat at all. I would make sure my part is indicated in nice and flat, and then set the spot drill to go in .002", that way the top of the hole would have a nice small chamfer.

As for not dwelling at the bottom of the hole, all I can say is duh. I also use the same coolant whether or not I drill .015" holes on the cnc or drilling 1" holes, I just set it to take such small pecks that chip packing isn't an issue.

As for the other stuff you said, yeah small drills aren't usually made for going that deep, and to be honest I would turn down that job if anyone ever brought it in to my shop.

[This message has been edited by mochinist (edited 08-17-2001).]</font>

This was/is intended to help solve Yankees problem not get in a pissing match.
You're welcome for the lesson. I've drilled a lot of holes in a lot of different materials, I'm sure you have too.

mochinist
08-17-2001, 10:30 PM
<font face="Verdana, Arial" size="2">Originally posted by Rustybolt:
This was/is intended to help solve Yankees problem not get in a pissing match.
You're welcome for the lesson. I've drilled a lot of holes in a lot of different materials, I'm sure you have too.

</font>

I can piss farther than you http://bbs.homeshopmachinist.net//wink.gif

YankeeMetallic
03-03-2006, 03:27 PM
I am designing a specialty burner tip for a glass blowing torch. It is going to require drilling over ONE HUNDRED .003" & .004" holes .25 deep within a .850" diameter Stainless Steel face, in a special pattern. I will be producing 100 tips which equates to over 10,000 holes total. My plan right now is to experiment with the different SS steels to see which ones resist warping at temperature. My hope is that 416 annealed SS will work because of it's machinability, with 303 SU or 303 SE as backup materials.
My question is, from someone else's experience would micro carbide drills break too easy, or would Cobalt drills be better because they are less brittle? Obviously I don't want to be spending mucho $ on the drills to be breaking them, or having to spend mucho time resharpening them due to drilling so many holes in the stainless.
Has anybody ever used a drill/reamer combo in this micro size that would be the ticket?
I have found Carbide reamer-drills for stainless but nothing smaller that 1/16".
Any help out there? Thank you in advance.

AZSORT
03-03-2006, 03:37 PM
There are outfits that specialize in perforated steel sheets. You can specify whatever patern you want and they can do quantity jobs very reasonably. A laser process I assume.

SGW
03-03-2006, 03:41 PM
The first thing I'd suggest is to figure out a way to drastically reduce the hole depth. Anything over about 3X the drill diameter gets to be "deep hole drilling," and you're proposing to go 60X to 80X.

Rustybolt
03-03-2006, 04:17 PM
Basically you want to drill a hole the thicknesss of a human hair, a 1/4 of an inch deep. Not really the material or thickness for such small drills. I bet this would be a perfect application for a laser or a water jet if they have orifices that small.

mochinist
03-03-2006, 04:21 PM
Are you planning on doing this on a manual machine, or a cnc? Also if you can resharpen .003" drill, let me bow down to you now, my eyes are pretty good and I have a steady hand, but I think I would toss a .003"drill before I would attempt sharpening it.

YankeeMetallic
03-03-2006, 04:27 PM
<font face="Verdana, Arial" size="2">Originally posted by mochinist:
Are you planning on doing this on a manual machine?</font>

Yep. Manual LAGUN with a Bison SuperSpacer and a DRO for bolt patterns. I will make the outer ring pattern first. Then program the next smaller diameter and reduced number of holes. Of course I would drill all parts with one specific bolt pattern, then reduce the diameter & pattern and drill the others, lather, rinse, repeat.
I haven't figured out the sharpening of the .003" drills yet though.

topct
03-03-2006, 05:01 PM
"It is going to require drilling over ONE HUNDRED .003" & .004" holes .25 deep within a .850" diameter Stainless Steel face, in a special pattern."

Forget it.

I would back up and think about this situation.

What about a piece of micro fine screen. Can be had in stainless?

[This message has been edited by topct (edited 03-03-2006).]

Evan
03-03-2006, 05:12 PM
Not going to work. Those sort of holes would be made with electron beam drilling which has been around for 50 years.

rsr911
03-03-2006, 05:16 PM
I suppose brass is out of the question? I have drill many carb idle, main, and air jet blanks in my time and find it rather easy with brass. As for 303 I just got done machining a part with it and so far it is my favorite stainless to drill. Do you have enough spindle speed for such small drills? Sounds like a pain on a manual machine, you have much more patience than I. On the other hand I doubt my CNC can feed SLOW enough to drill with bits that small. FWIW about deep hole drilling, I drilled a 0.500" hole through a 14" piece of 303 on my last project on my lathe as a pilot for a 1.250" hole, both holes where drilled dry and went perfect. I'd suggest HSS or cobalt, probably flood it real good as well.

------------------
-Christian D. Sokolowski

YankeeMetallic
03-03-2006, 05:42 PM
Based on the replies from those more experienced than I, perhaps that is why this new torch design has not been explored.
"Forget it."
"Not going to work."
"I would back up and think about this situation."

However I am rather stubborn and known for my resourcefulness. I'll keep working on it.
If anybody else has additional suggestions please submit them.

jkilroy
03-03-2006, 05:55 PM
Its not impossible, just highly improbable that you will be able to drill all of those holes in a single piece of stainless without breaking a bit off in the hole. Then the odds of you getting it out without damaging the piece are near zero. Farm it out to a laser cutting outfit is proabably the best idea.

topct
03-03-2006, 06:00 PM
When I said forget it. I meant what you are trying to do.

That's the drilling of that small a hole in that material and especially that thick.

What if the material was much thinner?

Evan
03-03-2006, 06:02 PM
If the pattern is circular then scribe slots in the OD of a piece of round stock. Shrink on a sleeve.

mochinist
03-03-2006, 07:13 PM
<font face="Verdana, Arial" size="2">Originally posted by YankeeMetallic:
Yep. Manual LAGUN with a Bison SuperSpacer and a DRO for bolt patterns. I will make the outer ring pattern first. Then program the next smaller diameter and reduced number of holes. Of course I would drill all parts with one specific bolt pattern, then reduce the diameter & pattern and drill the others, lather, rinse, repeat.
I haven't figured out the sharpening of the .003" drills yet though.</font>

If it works it is going to take a long time and is definately going to test your patience. I would be worried about your spindle speed, a drill that small is going to need to be ran really fast and is going to need to be done one smallpeck at a time. I regulary drill .015" to .032" holes in copper and aluminum, anywhere from a half inch to a little over an inch deep. I like the taper length drills because they are longer and have more flute to clear the chip. I run these drills at about 6000 rpm and I peck drill with a full retract out of the hole after each peck of .005" to .003"(depending on the size of the drill), and I am running flood coolant of course. The deeper holes usually take about 6 minutes to do.

If I was you I would look into getting a sensitive drill chuck, made for doing small hole drilling, or maybe even a drill press made for doing small holes, someone posted something about them either here or at the PM site, I don't remember where though.


<font face="Verdana, Arial" size="2">However I am rather stubborn and known for my resourcefulness. I'll keep working on it.
If anybody else has additional suggestions please submit them.</font>One other thing to look into is lost egyption wax casting. I know very little about this process, but I do remember back in one of my CNC classes I had a teacher that worked at HoneyWell, anyways one day he brought in some sort of fin that went into a jet engine. It was a rather simple looking little fin, but it had little tiny cooling holes running throughout the fin. He said the whole part was cast and held to extremely tight tolerances, it needed no machining after the casting process. I don't remember what the material was, but it was definately not aluminum or bronze.

Evans last two ideas also sound good.

Good luck with however you do it, you are going to need it http://bbs.homeshopmachinist.net//wink.gif

YankeeMetallic
03-03-2006, 07:23 PM
My max speed with my mill is 4200 rpm. I just picked up a nice Albrecht micro drill chuck with manual feed shank. I am going to test drill some different materials when I get the chuck.
Then I'll get a bid for a laser or water jet job for the holes and see if I come out ahead. Finding a shop with a laser around here will be a bit difficult.
I may have to change the design if it doesn't work, which would mean applying for another patent.

herman williams
03-03-2006, 07:27 PM
Hello
Another idea would be to use an EDM hole popper.
re

J. R. Williams
03-03-2006, 07:50 PM
Step drill the holes from the back side leaving only 0.003 to 0.005 inch for the small hole. You are wanting to do the almost impossible.

I remember one time a new machinist came into the shop looking for work. He made comments on his ability. The old shop foreman gave him a small job to drill a series of 0.020 inch cross holes in a 1/4 inch stailess steel rod along with a box of drill bits. The 'hot shot' worked for a while and finally stormed out of the shop and left. His ego was left on the bench in the form of broken drills on the bnch and in the work.

JRW

rkepler
03-03-2006, 09:30 PM
This is one of those "NFW" requirements. There is no freaking way that you're going to drill those holes. Some time ago I was drilling .006 holes in .125 stainless and had to thin the back to about .060 (minimum thickness I could take it to as it was a guideway for optical fiber) before I had any production, and at that would lose multiple parts to make one (the drills looked a lot like hair from my dog).

If you knock out the back to .025 or so you could pop all the holes with a laser, but it's not going to be cheap. I think the holes will have some trouble with greater depth.

Makling an assumption here: If you're trying to get laminar flow of the gas why not simply stack some tubes with about the same total aperture with the holes and spaces between the tubes? I've gotten laminar flow on a larger basis using soda straws in a frame, seems to me it's work with hypodermic tubing as well.

Forrest Addy
03-03-2006, 10:09 PM
Is there any way you could finesse the drilling?

They make real skinny bore hypodermic tubing. How about using a bonded array of tubing orifaces? Once bonded the faces could be lapped and etched to get clean exits and entrys.

Photo multiplier imaging arrays consist of tens of thousands of glass tubes fused and drawn as a mass to a small diameter with the lumins somehow staying complete and in proportion to the size in the original array. Will glass work as your perforated media?

The people who make porous sintered metal products can provide most any alloy, porosity, and reactivity you could desire. Furthermore this stuff can be supplied in most any shape and thickness and will EDM without losing its properties.

wierdscience
03-03-2006, 10:49 PM
My idea would be to have the holes lasered in to SS shim stock first and then sandwiched into the required thickness.

I don't see drilling those as being a good option.

YankeeMetallic
03-03-2006, 11:15 PM
<font face="Verdana, Arial" size="2">Originally posted by Forrest Addy:
Will glass work as your perforated media? </font>

You may be onto someting with the glass. And since it is for glass blowers maybe I can get some input from them on the rods & tubes available in the market.
Thanks for the input.

Ries
03-03-2006, 11:56 PM
I dont know much about glassblowing burners, I have just seen em use either glory holes or torches-
But I have a propane forge I use for blacksmithing, and the burner on that is cast refractory.
Takes the heat, and is sure a lot easier to drill than stainless. Mine was made by my buddy, its about 3" in diameter, with about 50 holes in it, larger than what you are thinking, probably about 1/8" diameter each.
The whole casting is about an inch thick.
No worries about breaking bits, and in my forge, it has lasted more than 4 years now, lots and lots of heating and cooling cycles.

YankeeMetallic
03-04-2006, 12:28 AM
I wish I could explain this better to get better advice, but there is a patent pending on this design (if I can get it to work).

Evan
03-04-2006, 01:02 AM
The micro channel plates for image intensifiers are made by bundling a bunch of dual layer glass rods together. The rods are made of two types of glass, the core can be dissolved without etching the cladding. The bundle is fused together and drawn out to reduce the diameter of the constituent rods and then plates are sawed off and etched to create channels where the core glass was.

Laser drilling at that size isn't suitable for such a deep aspect ratio. Laser drilled holes tend to taper with depth. Electron beam drilling can go that deep and is faster than laser. Electron beam can punch holes in thin stainless at the rate of a couple of thousand per second and can go as deep as .250" at a slower rate, even in ceramic.

model a
03-04-2006, 03:23 AM
I suggest a photolithography process, you coat the substrate with a photo resist, expose the part you want to harden to uv light and rinse the unexposed part away (your hole pattern). The next step is that you etch away the metal where the holes need to be. This would never work with something as deep as you "dream" of going though.

Rustybolt
03-04-2006, 09:38 AM
<font face="Verdana, Arial" size="2">Originally posted by mochinist:
Are you planning on doing this on a manual machine, or a cnc? Also if you can resharpen .003" drill, let me bow down to you now, my eyes are pretty good and I have a steady hand, but I think I would toss a .003"drill before I would attempt sharpening it.</font>

Tiny drills are made for drilling very thin materials.The next questiion would be; how do you center them? Almost any center drill is going to have a chisel point that is going to leave a flat an the bottom. No matter what the material you don't dare dwell at the bottom of the hole or the drill will instantly dull.You have to be careful of the coolant used so as not to accumulate chips and pack the hole and thus break the drill.
There is CNC equipment adapted to to drill tiny holes, but 1.4 is too deep. Mabe if you back relieved the hole in steps. say a #60 down to .200 and then an #80 to say .040-.045 then drill the rest .004. Let us know how this turns out.

Evan
03-06-2006, 11:17 AM
bump

Wirecutter
03-06-2006, 07:14 PM
Um, this may not necessarily help Yankee, but...

Historically, solving "impossible" problems has been were a lot of people and corporations have become really successful. I can remember full-height 5" hard drives coming on the scene. Tell someone then that in 20 years, we'd have Compact Flash sized hard drives with 1 Gig capacity, and they might think you're nuts. (well, maybe not - look at memory density increases)

I've seen stainless tubing with .001" ID and .001" wall thickness. That was 15 years ago, and I'm sure even then, the stuff could be had in smaller sizes. Oh, and I also saw that same tubing welded, by hand, and without damage, by a bunch of Vietnamese women working in a plastics factory.

Perhaps a better question for Yankee is how much are you willing to spend? You can bet your boots that if the US government had a need for such a thing, they (or someone) would find a way, and fast. Problem is, I doubt Yankee is willing to start up and supply some kind of money pipe... http://bbs.homeshopmachinist.net//biggrin.gif

And no, I can't piss particulary far. http://bbs.homeshopmachinist.net//wink.gif