On 06/14/2010 03:42 PM, Wes wrote:
Tim wrote:

Then I thought "Ah ha! Delrin is a pain to machine because it squirms
away from the bit! I'll drill a 1/16" hole, then widen it with the
5/64" bit!" Success! the 5/64" bit took out enough material for a good
press fit on the shaft.

Never say die, and you may just succeed!

(Interestingly enough this also doesn't belong on _rec_.metalworking
because it's for a customer project -- I needed a flywheel on a test
article that I'm writing control algorithms for -- the _real_
metalworking involved was making the steel outer edge for the flywheel,
that the Delrin hub presses into).


What do you mean work doesn't count? I made a crappy little tool consisting of a .55 dia
pilot that fits into a pneumatic piston we have to put a U cup on. Round thing screwed to
a piece of .50 x .25 x 3" stock that has a strategically placed 3/16" dowel pin pressed
though the rectangle stock that just clears the edge of the piston by 0.010" so if they
get the U cup started, a twist of the wrist spins it on.

Request from one of the ladies on my assembly line.

Of course the engineer had to approve it, he of course started improving it (we will see)
but he did take it out to the line for use until he gets his tool made his way.

Well, if he does improve it then huzzah! And if he's smart enough to
get out of the way when yours works -- huzzah twice!

One of the things I needed to learn as an engineer is when you want to
just get by with a crappy little tool, and when it's essential that you
step back, take a deep breath, and really _design_ something.

I don't know if I'm there yet -- I've finished projects, fat and happy
in a pile of new tools, then realized that I could have done the whole
thing with a sharp stick and a rock.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

Tim Wescott wrote:

Of course the engineer had to approve it, he of course started improving it (we will see)
but he did take it out to the line for use until he gets his tool made his way.

Well, if he does improve it then huzzah! And if he's smart enough to
get out of the way when yours works -- huzzah twice!

I found his solidworks file on the network today ( I have RO access to engineering) and
inserted the piston into his assembly. He did okay. Drew it with the pin tangent to the
piston but he has enough clearance for the fastener that I can slide the handle out enough
for it to work as I made my proto type. I wanted the pin 0.01" proud of the piston on the
diameter.

(worse comes to worse, I have a round file )


One of the things I needed to learn as an engineer is when you want to
just get by with a crappy little tool, and when it's essential that you
step back, take a deep breath, and really _design_ something.

I don't know if I'm there yet -- I've finished projects, fat and happy
in a pile of new tools, then realized that I could have done the whole
thing with a sharp stick and a rock.


I made a sharp stick and a rock product to prove my idea. He did pretty it up a bit. Wish
I could post pictures of mine and his but that NDA is in the way.

He did okay, there was one change I wanted to make and he made it as I suggested.

I'm pretty happy with it.

Wes

Tim sez:

"I don't know if I'm there yet -- I've finished projects, fat and happy
in a pile of new tools, then realized that I could have done the whole
thing with a sharp stick and a rock."

Right on, Tim ! It kinda differentiates engineers from the "inspired tinkerers" from whom most
great ideas originate. It adds validity to the old saw which states, "Technology without
mathematics would only be two weeks behind".

Bob (I are one) Swinney

Tim Wescott wrote:

I don't know if I'm there yet -- I've finished projects, fat and happy
in a pile of new tools, then realized that I could have done the whole
thing with a sharp stick and a rock.

Everyone does. If you can remember what tooling you have on hand, (that is starting to be
an issue for me both at home and at work) your options have increased.

IOW, if you have three ways to do something, maybe you will think of one of them before
buying something else.

Wes
--
"Additionally as a security officer, I carry a gun to protect
government officials but my life isn't worth protecting at home
in their eyes." Dick Anthony Heller