Suggestions

[L Hanft]

Making part for research project. 16 gauge 304 SS need to drill 300-500 1 MM holes in each part. Using bench top CNC no coolant, only air to blow chips. Any ideas on feeds, pecks, etc..... have a limited supply of bits!

[Balbir]

Are you using HSS or Carbide?

It is very hard without coolent, But you can use cutting oil and 40-50SFM(approx. 3000RPM)with .0005-.001 Chip load and try to use .01-.015 peck for 1MM drill.

Good Luck

[L Hanft]

Thanks for the reply. I will be using 1 mm cobalt twist drills. Not having coolant is a problem.

[BernieT]

Have you considered getting a spraymist add-on. Trico makes a model 30605 with 2 nozzles that turns on and off with M8 and M9 in the program and the spray is adjustable from air only to coolant only with everything in between. I'm guessing the cost is around $600-700.

Just a thought...

BerTau

[L Hanft]

BerTau... I am at a major university... engineering.... but budget cuts have created problems.... I would like to add some sort of mist system but... can't afford anything this year!!!

[camguy]

buy some plasticine,or play-dough, or anything similar, roll it out and build a dike about 1/4" high around the edge of the part and fill it with coolant. you may have to top it up a few times, but it should be enough to do the job. Good luck.

[Guy]

You could try right-tru coolant maybe...

------------------

Guillaume Côté

Hexco inc, Montreal Canada

Stainless steel specialist

[mikee]

Try Boelube and a acid brush. Works great with stainless or other exotic material. I belive MSC carries Boelube. You can use this in a mist system also.

mike

[Guest]

Any type of a spray bottle will accomplish the same thing. However, if the little bench machine has no covers on the servo motors, be cautious... could be trouble. (It would work for a little while then Buzz, Buzz, Pop... No more machine and an "F" on the project!)

Andrew

[Ambassador]

Also you will want to Flatten the edges of the drill and leave a point in the center. This will stop the material from deforming as the twist drill goes through. If you leave the standard 118 degree angle, you may find the SS will either xxxx the drill as it breaks through or pull up and deform the piece. This also acomplishes center drilling.

Ambassador

[This message has been edited by Ambassador (edited 07-23-2001).]

[Chips Ahoy]

I've drilled many holes in #304ss and I prefer a split webb drill. If the webb of your drill is not split already "good luck on splitting it" you will need a good drill grinder or a steady hand. You could also order some drill bits that have the webb split already. Ptd brand might go that small in a QC or EZ style. I liked the idea of putting some putty like substance for the swimming pool. You could also put some duct tape under the part so the water won't leak out. Once the drill goes through, the hole will close back up to hold the coolant in the machinist bathtub that you have created.

[Trevor Bailey]

What Ricky said is real important. Use a split point drill with 135 tip angle. There is also a "canister" type coolant that only blows extremely cold air. It works great from what I understand for applications like yours where you can't use liquid. Check out MSC on the web or call 800-645-7270 for more information. YOu hook it up just like a spray mist system. Very simple.

The sytem is called Vector Air Cool.

Hope this helps,

[ 07-30-2001: Message edited by: Trevor ]

[L Hanft]

Thanks to all that replied to my problem....

Lots of good suggestions. So, here is what I have done. Since I am using 1 MM drill bits, there is not a lot of choice on tip design etc. Because the machine is small and can only reach 75% of the part I created an indexable fixture with a shallow pocket. This allows me to create a pool of fluid and turn the part 180 to be able to reach all the part surface. The 1 MM bits are tricky... they flex, walk, and break with ease.......... now how do I debur the holes?

[awheeler]

For lots of holes the fastest way I have found to deburr them is to use a small countersink in a cordless drill. I usually use the slow setting so I dont take off too much material. This isn't highly accurate but it is quick and easy.

[Will Slota]

You could load a wire cup brush in the spindle and run it over the top of the holes to break off the burrs...maybe!

[Chips Ahoy]

Deburring the holes could be tricky. I have at time taken a fine Arkansas stone over the face of the part you have drilled. It then has a tendency to push the burr into the holes but, loosens the burr up. I have then taken the part to the glass bead blaster and cleaned up the holes beautifully. It also usually cleans up the scratches that the stone had left. This is "usually" an exceptable finish to most customers.

[L Hanft]

Some good deburing suggestions, 1 MM is approx. 0.0394... 0.0385 if you measure the tool..... maybe I'll let the customer worry about deburring!