Serious - Drilling a square hole

[Rusty Heap]

VERY interesting cammed cutter chucked up in a CNC cutting chips in an aluminum test fixture.

Yup, drilling a square hole.

Slo Motion Video:

drill.mp4 video by randallwhitman - Photobucket

[Scott Douglas]

Dang, never would've believed it.
Thanks for posting this.

[widebody911]

Reuleaux Triangle -- from Wolfram MathWorld

[motion]

I watched the video and I still don't see how its possible... guess its not a true square. I had squares cut with a plasma burner a while ago into a piece of 3/16 diamond plate. Cool stuff.

[drcoastline]

Originally Posted by motion

I watched the video and I still don't see how its possible... guess its not a true square. I had squares cut with a plasma burner a while ago into a piece of 3/16 diamond plate. Cool stuff.

it looks like theres a dual action in the drilling process

[Reg]

what about a mortise chisel? 4 sided chisel with drill bit in center - been around for ages.

[MattKellett]

It using two processes to make the square hole. Basically rotating and chiseling, but the thing is moving so fast that we can't see the tool doing the chiseling.

I suspect it pauses rotation for a fraction of a second, while it chases out the corner with the chisel part of the cutting tool, similar to a hammer motion.


Edited - Basically as Reg says above, the wood working tool for this has been around for ages. Still a cool cnc process.

2 nd edit, if I'd bothered to watch the end of the video, I would have seen this!

[Hard-Deck]

I have a mortiser for woodworking, not new tech.

[Hawkeye's-911T]

If I remember correctly from a technical lecture (far too many years ago), it is theoretically possible to drill any multi-sided polygon shaped hole. The trick is to set up some kind of drive unit for the bit to perform a necessary similar type motion as shown in the video. The drill bit would always have one less cutting side than number of faces in the drilled hole, hence the 3 'sided' bit for a four sided hole. I would guess maybe it follows that one could not drill a 3 sided hole. At the end of the day, it probably has limited practical applications.

Cheers
JB

[Dantilla]

Old technology or not, somebody way smarter than me figgured that out!

[Normy]

The specially-shaped bit moves in an eccentric motion. It is impossible to drill a square hole with just rotary motion. This whole thing requires a special drill, not just a special bit.

N!

[Rusty Heap]

blah blah blah, end of the day, it's cool to watch, UNDERSTAND, and hence I posted it...........

cough cough, so credit to the guy who give 2 edits to his post before even watching to the end of the 2 minute video.

geez they show the rotary cammed XY motion diagram in the first :20-:25 seconds.


things must be needed faster in CA. Microwave not always better, slow roasted meat gooderer

[Flieger]

If the hole is big enough you can just use a normal milling machine bit on a square path. Then you even get nice radius edges as well. This looks better than broaching, though.

[masraum]

Haven't you ever done a crappy job of drilling through thin sheet metal and ended up with a hole roughly shaped like this with a regular old drill bit.

[DUK]

I was just going to say, my drilled holes usually look triangular. So really I've already accomplished 3/4 of what they just did. LOL

[Porsche-O-Phile]

Very cool - I'm thinking of all kinds of uses for that...

[dondarnell]

UK company Microbore makes tools that will do this and more....