For you machinist out there...

CaptPatrick · Post by **CaptPatrick** » Oct 31st, '11, 10:26

Brewster Minton · Post by **Brewster Minton** » Oct 31st, '11, 10:39

New meaning to a square peg in a round hole.

Harry Babb · Post by **Harry Babb** » Oct 31st, '11, 15:27

Now being able to drill a square hole....ON PURPOSE.....opens up a whole new world! ! !

I am the king of drilling a triangular hole with a round bit! ! ! LOL

Several years ago I had to make some parts and supply Socket Head Cap Screws with the order.....these bolts were 1'' thread size and made of XM-19.....due to the alloy I had to have them custom made.

I found a place in South Florida that could produce them. I thought the "Hex" had to be Hot Formed, but when they came in it was obvious that they had been machined......blew my mind.......no significant radius in the corners either.

I am thinking that if these guys can do a Square hole they probably can do a Hex hole.....

Good one Capt

hb

Carl · Post by **Carl** » Oct 31st, '11, 16:55

Harry,
You can do a Hex, Spline, Key, Square pretty much any shape with a Wobble Broach in the lathe, mill or even a drill press.

Real simple tool in theory, Cutter looks like a punch with a sharp concave face, and a good deal of draft. Cutter goes into a head and tool bit spins freely with the work, the head is offset. After you have hole to spec you introduce cutter to hole and as tool spins with the piece, the front face cuts/ shears the shape. Works pretty good...although the heads are pricey and tools are not cheap, but with the right job...

Capt Pat that is a pretty cool clip.

Wanna see something mind blowing...at least to me it is. I understand how it works yet it still escapes me how its done. After the 2 minute mark is where it gets interesting

http://www.youtube.com/watch?v=FfPGGVceO6g&NR=1

randall · Post by **randall** » Oct 31st, '11, 17:29

that is cool......usually i can visualize how things work....this time time....not so much.

ianupton · Post by **ianupton** » Oct 31st, '11, 17:38

This might help.

The bit does not rotate on its' center, and the corners of the square are not really squared off.

From Wikipedia - "The Harry Watt square drill bit has the shape of a Reuleaux triangle and can, if mounted in a special chuck which allows for the bit not having a fixed centre of rotation, drill a hole that is nearly square."

Ian.

Capt.Frank · Post by **Capt.Frank** » Oct 31st, '11, 18:55

Amazing.

mike ohlstein · Post by **mike ohlstein** » Oct 31st, '11, 22:42

Saw it done many years ago, but you still had to clean up the corners.

You can draw a cross section of the drill bit pretty easily.

Draw any line. Use a compas to span the length of the line, and then use it to draw an equilateral triangle. Put the point of the compas on any corner and scribe the arc between the other two points. Repeat for the other two points. Have Harry mill up the bit, and put it in a wobble chuck.

Of course some folks can drill square holes with a standard drill bit, but most of us would call that wallerin'......

Rawleigh · Post by **Rawleigh** » Nov 1st, '11, 10:01

Square drilling has been around since the turn of the century. Those old guys were pretty smart.

Harry: Google "Rotary broaching" and you will see how they may have done it. Any shape you want! Tool stays stationary to the work and the rotation of the chuck makes it wobble to do the broaching.

http://www.youtube.com/watch?v=gUEcagEmmZo

It also works on a mill and you can really see the wobbling action.

http://www.youtube.com/watch?v=uTsPXFy7 ... re=related

coolair · Post by **coolair** » Nov 1st, '11, 21:51

That is awesome. there are way to many cool things i know way to little about

scot · Post by **scot** » Nov 2nd, '11, 16:58

I believe they call that a Mazda Rotary (Wankle) engine.

Harry Babb · Post by **Harry Babb** » Nov 2nd, '11, 19:08

Several years ago a guy came in the shop and need a bearing pressed off of a shaft.

This shaft was part of a Gear Reduction that he used on his barge and tug.

The inner workings were eccentrics, plates, and pins that would act as a gear reduction and would not free wheel at all.....there was not the first gear inside of this thing and looked as like a very simple device.....but had some pretty complicated geometry.

for the life of me i cannot remember the name of the reduction or the manufacturer.....From what i remember he told me it was not very expensive.

It worked on what looks like the same principle as the square drilling hole.

I know the description is rather vague....but have you guys ever ran across a gear reduction like I tried to describe??

hb

jspiezio · Post by **jspiezio** » Nov 3rd, '11, 07:36

Harry, I think I found it-

http://en.wikipedia.org/wiki/Cycloidal_drive

Harry, it sounds like a trochoid or gerotor gear. They are used a lot in hydraulic pumps.

Here are some links:

http://en.wikipedia.org/wiki/Gerotor

http://en.wikipedia.org/wiki/Hydraulic_pump

Harry- I was curios and looked around, any of these?

http://en.wikipedia.org/wiki/Sun_and_planet_gear

http://en.wikipedia.org/wiki/Epicyclic_gearing

Harry Babb · Post by **Harry Babb** » Nov 3rd, '11, 17:33

Well Joe I got real curious also and could not get it out of my mind.....so I did a little digging and found what I am talking about.

Take a look
http://www.youtube.com/watch?v=YRATbJs6 ... re=related

http://www.youtube.com/watch?v=EFni742p ... re=related

hb

jspiezio · Post by **jspiezio** » Nov 3rd, '11, 21:16

Wild stuff!

BCBertie · Post by **BCBertie** » Nov 3rd, '11, 22:04

Harry Babb wrote:Well Joe I got real curious also and could not get it out of my mind.....so I did a little digging and found what I am talking about.

Take a look
http://www.youtube.com/watch?v=YRATbJs6 ... re=related

http://www.youtube.com/watch?v=EFni742p ... re=related

hb

Man, that is beautiful. There is genius in this world...

bertram31.com

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