Need Help!- Tooling questions??

[tskguy]

Hi all,

Im a bit of a newbie and just recently built a CNC router to help build microphone capsules. I found a video that shows some CNC machining of exactly what Im building. I have some questions for you experts out there regarding tooling and hold down fixtures.
I need more info regarding the CNC drilling portion but the lathe stuff would very helpful as well.

Here is the video;

YouTube- How It's Made (Season 11 / Episode 7 / Part 1)
THANKS!!!!!
Eric

[tskguy]

Anyone???

At least the video is cool to watch.

[will gilmore]

What is your question specifically?

[tskguy]

Ok my specific questions are this.

If you watch the video at 2:20 mark they are drilling a microphone capsule.
I want to know what they are using to hold down the part for drilling. I also need to know the two different methods they are using to drill the holes. It looks like the first step is just a diamond bit drilling starter holes. The second bit is what I cant figure out. It looks to be off center. Just to give you guys an idea of scale the holes they are drilling are .7mm and 1.1mm. Pretty small stuff. At the 2:30 mark they are sowing a facing operation. I need to find out what kind of collet the are using to hold the capsule. I also need to know what kind of tool they are using for the facing operation. Its something Im not familer with. Thats about it.

Thanks in advance!!!

Eric

[will gilmore]

I haven't done a lot of small hole drilling but looks like a center drill first and then the proper size drill bit. I see the wobble you are talking about but I dont know what it is. It's in one of the edge holes. Could they be tapping? As for the collet I'm sure they use a custom bored soft collet that fits their lathe. You can do the same. Lathe tools are called trepaning (cutting grove into face of work) and facing.

[tskguy]

YES! They are probably tapping. I didn't think of that. Thanks for the other info.

As for the lathe collet I think I have a good idea. What about the chuck they are using to hold down the brass for drilling. Any ideas?

Thanks for the help

Eric

[will gilmore]

Originally Posted by tskguy What about the chuck they are using to hold down the brass for drilling. Any ideas?

Another custom fixture. How many of these are you doing? You could clamp that part in a vice. A fixture lets you load blanks in the same place everytime (production).

[tskguy]

I want to do a bunch of them. Also there is a another set of holes on the other side of the brass and its very important to flip the part as accurately as possible because the hole depth can converge. Hope thats clear. I'm using a 3 jaw chuck from a lathe already. It works OK but its a little difficult to get good repeatability.

Eric

[will gilmore]

3 jaws are not very repeatable. Do you need the part to be rotationally indexed during the flip? maybe you could make a rectangular fixture to clamp the part to and flip the whole fixture. easy to clamp in a vice doesnt rotate or move. even better make a fixture that holds a bunch of the plates. machine the tops of all of them, flip the whole fixture and finish machinging. even better build a 4th axis that will flip the fixture for you...

[tskguy]

Thats a good idea!

I will give that a shot. Sadly building a fourth axis would be a little out of the budget!

[will gilmore]

I'm curious what you come up with. Post some pictures when you get it done.

[tskguy]

I will!

Its been a frustrating road, hopefully I will get this figured out!

Eric