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View Full Version : Rotary Multi-Axis Index Table For EDM?



Swamp Donkey
01-09-2005, 05:50 PM
My business is diesel fuel injectors for truck and tractor pullers, and I'm looking to get an EDM machine to drill small holes in the injector nozzles, ranging from .006" to .012", with 3-10 holes being drilled in each nozzle.
I'll probably get an Agie Charmilles unit that's in the 34K price range.
The injector nozzles are roughly cone-shaped with a tip the diameter of a pencil point. I need to drill holes at a point equivalent to where the lead comes out of the wood on a pencil.
The holes are not all on the same plane; the axis of the holes in relation to the axis of the nozzle varies from ~7* to 33*.
So, I need to rotate the nozzle, and change the angle of inclination, but still keep the nozzle under the electrode.
A rotary index table on a sine plate will give me the different angles, but I don't like the idea of manually resetting the angle after each hole.
I looked at all kinds of multi-axis index tables on the web, but they were all way too big to fit the machine, and it looked like the nozzle would swing out of position under the electrode ever time I changed the tilt.

Any suggestions?

JIMofalltrades031
01-09-2005, 06:00 PM
If I understand you correctly couldn't you set up on a standard indexing jig and set the edm head at the first angle cut those holes and then shift the edm head to the next angle and cut those holes? Maybe I aint gettin it.

John Stevenson
01-09-2005, 06:02 PM
One way I can see to do this is to use two rotary axis an A and a B.
The A holds a jig that also holds the B axis which is just a rotational axis.
You set the injector nozzle so the centre of the tit is on the 0,0 axis in a collet on the B.
This will allow you to alter the tilt on A without loosing reference under the EDM and the B will allow you to index round x number of times.

Can you follow this.?

Have a look at http://www.divisionmaster.com for some ideas.

John S.

Sprague M
01-09-2005, 06:53 PM
Sounds as though you would be using a sinker edm. If so the fluid and tank can severely hamper the available working area and all fixturing if electrically powered would have to be sealed. An edm drill or "hole popper" would be less expensive and more open to additional Programmable axis.

Swamp Donkey
01-10-2005, 02:43 PM
It's a hole popper, not a sinker.

John,
The table in the link will definately take care of the rotation aspect, but now how do I do the tilt?
For instance, I could set the table up so there is a 110* angle between it and the machine table. But, if I rotate it, all the holes will be at the same angle in relation to the nozzle axis, whereas I'll need them between 7* and 33* or so, but with no two on an injector the same.
I know that I could put it on a sine plate, but it seems to me that every time I changed the angle on the plate, that I'd have to reposition the nozzle under the electrode, and that sounds like a lot of opportunities to get something misaligned.

(I'm new at a most all of this machining stuff, so there's a lot of basic stuff I don't know, so its really possible I'm overlooking something simple.)

Thanks, guys!