Mill choreography
 

Tom Gardner wrote:

I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events. With my old BP
and methods I guess this would have taken close to two days! And, every
operation was within two thousandths. Think/cut!

So, after all that outrageous productivity, I took a little nap at my desk!


And just how much extra time did all that prep take? :-) :-)
...lew...

Mill choreography
 

"Tom Gardner" wrote in message
...
I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations
with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events. With my old BP
and methods I guess this would have taken close to two days! And, every
operation was within two thousandths. Think/cut!

So, after all that outrageous productivity, I took a little nap at my
desk!



I've long been of the opinion that a machinist should have the right to had
a
drawing back to the designer and say, "there's the mill; go make it..."

A little cleverness in the design can save a world of time (and cost) in the
making...

Jerry

Mill choreography
 

"Tom Gardner" wrote:

I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events.

[snippage]

I'm probably not the only guy that gets part way through something and
change how I process things as I figure out a better way to do the job.
Maybe some day I'll consistently get it right from the start.

Wes

Mill choreography
 

"Jerry Foster" wrote:

A little cleverness in the design can save a world of time (and cost) in the
making...

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

Wes

Mill choreography
 

"Wes" wrote in message
...
"Tom Gardner" wrote:

I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations
with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events.

[snippage]

I'm probably not the only guy that gets part way through something and
change how I process things as I figure out a better way to do the job.
Maybe some day I'll consistently get it right from the start.

Wes

Ayup! I try not to cut metal until we are on version 3 or better in
Solidworks. Even then, I make note of all the improvements for the next
version of a machine subsystem but we don't change design in the middle of
the build anymore, that version gets built and run knowing another complete
version might be justified. I have to be careful not to let the good be the
enemy of the perfect.

This machining I did was for version 3 of a mechanism that has been in use
for four years. I haven't thought of a single improvement yet and it will
go on a production machine next week. If it works, it will be the last
version...probably.

Mill choreography
 

On Oct 12, 11:11 pm, "Tom Gardner" wrote:
So, after all that outrageous productivity, I took a little nap at my desk!

This is sort of related and I'm dying to share it with the group, so I
think I'll put it here. I just got back from a trip to the good old
Boston area and made it a specific goal of my trip to visit the
Starrett factory in Athol, MA when I was there. I went and devoted
about 3 hours to the place. In particular, I had called ahead and
found out that if you ask them, they will send down an apprentice to
give you a tour of the factory. I went on the tour and was amazed by
what I saw.
Basically, the Starrett approach to manufacturing is to use older
specialized machines and toolroom-built tooling and fixtures specific
to each type of component, rather than more expensive, newer,
multipurpose machines. There inventory rarely undergoes major changes
and so these make sense. This is not to say they don't use CNC, for
example, I saw a half dozen high capacity CNC milling centers
(Japanese, as it turns out, don't remember the exact company) turning
out parts dozens of times faster than manual equivalents. However,
they still use over a dozen automatic multi-spindle screw machines to
turn out all sorts of parts. Not CNC, changing the part requires
manipulating cams and gears inside the machine, they still have an
edge over a CNC turning center. In particular, they have 6 spindles
rather than just one. I saw machines with more than a 2" bar
capacity, dating back to the mid 1900's.
I found this system of specialization and custom tooling to be very
much suited for the kind of production they make.
ww88

Mill choreography
 

I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events. With my old BP
and methods I guess this would have taken close to two days! And, every
operation was within two thousandths. Think/cut!

So, after all that outrageous productivity, I took a little nap at my desk!

Mill choreography
 

On Sat, 13 Oct 2007 01:01:54 -0400, Wes wrote:

"Jerry Foster" wrote:

A little cleverness in the design can save a world of time (and cost) in the
making...

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

Wes

That was somewhat the case at one time in some places. It's still a
good idea. New engineers weren't exactly apprentices because they
didn't need to achieve the skill level that an apprentice must to
become a journeyman. They were there to gain an appreciation of what
is done and how things work on the shop floor, in the drafting room,
in the test & eval lab, etc -- and the only way to gain that is by
doing it, working side-by-side with people who do it for a living.
Newly-degreed young engineers did not design anything until they had
about 2 years of such OJT and experience to complete their education.

Mill choreography
 

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.


30 years ago, as a new engineer fresh out of school, I had coffee with the
shop foreman and mentioned to him I'd like to know more about he made
things. He set me up with a couple second shift fellas. I learned a ton AND
got a bunch of government projects done. Plus, making good friends in the
shop made all those rush jobs get done on time.

Any young engineer should do the same thing today.

Karl

Mill choreography
 

"Wes" wrote in message
...
"Tom Gardner" wrote:

I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations
with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events.

[snippage]

I'm probably not the only guy that gets part way through something and
change how I process things as I figure out a better way to do the job.
Maybe some day I'll consistently get it right from the start.

Wes

Having worked from prints for what seems my entire life, it wasn't uncommon
for me to redraw (on scratch paper) and re-dimension parts so they were
meaningful in the way they'd be made. No changes were introduced, just
dimensions provided in a way that was useful. By working to nominal
dimensions at all times, you are able to use any portion of a machined piece
as the datum point. That's important when you start changing reference
points.

Harold

Mill choreography
 

Tom Gardner wrote:

This
by changing the way I do my drawings and visualizing all the operations
with the thoughts of reducing set-ups

There are many different ways to make a drawing with different ways to how
to place the dimensions.
For manufacturing
For functional checks (in the pre-CAD times)
For structural analysis
For quality checks


Nick
--
The lowcost-DRO:
http://www.yadro.de

Mill choreography
 

Wes wrote:

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

I know that some companies punish stupid or hard to assemble constructions
an engineer did by sending him to the assembly line and letting him do the
work for at least one day.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Mill choreography
 

"Tom Gardner" wrote in
:

I did 18 mill operations in less than 2 hours including set-up time.
This by changing the way I do my drawings and visualizing all the
operations with the thoughts of reducing set-ups, minimizing tool
changes, laying out the tools and parts and figuring the correct order
of events. With my old BP and methods I guess this would have taken
close to two days! And, every operation was within two thousandths.
Think/cut!

So, after all that outrageous productivity, I took a little nap at my
desk!



Tom,
Here is a post I wrote a few years ago over in a.m.c., that addresses
what you are talking about.

Long URL:
http://groups.google.com/group/alt.m...thread/ac5d019
1487bbb6a/c1cfd4b753dd32fd?lnk=st&q=#c1cfd4b753dd32fd

Tiny URL:
http://tinyurl.com/3cum59

--
Anthony

You can't 'idiot proof' anything....every time you try, they just make
better idiots.

Remove sp to reply via email

Mill choreography
 

Wes wrote:
"Jerry Foster" wrote:


A little cleverness in the design can save a world of time (and cost) in the
making...


I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

Wes

And repairing them also....

Paul


--
-----------------------------------------
It's a Linux world....well, it oughta be.
-----------------------------------------

Mill choreography
 

In article ,
Nick Mueller wrote:

Wes wrote:

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

I know that some companies punish stupid or hard to assemble constructions
an engineer did by sending him to the assembly line and letting him do the
work for at least one day.

A smart company (try and find one of those) would do it as S.O.P.,
regardless of design "good" or design "bad" - the opportunity to see
what went right and what wrong, and what thing the designer thought
would help that's irrelevant, and what thing the designer thought would
be easy that's hard - all these are important.

--
Cats, coffee, chocolate...vices to live by

Mill choreography
 

Thats where the Methods Engineer comes in. He/she bridges the gap between
the designer and the machinist.


"Jerry Foster" wrote in message
. net...

"Tom Gardner" wrote in message
...
I did 18 mill operations in less than 2 hours including set-up time.
This
by changing the way I do my drawings and visualizing all the operations
with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events. With my old BP
and methods I guess this would have taken close to two days! And, every
operation was within two thousandths. Think/cut!

So, after all that outrageous productivity, I took a little nap at my
desk!



I've long been of the opinion that a machinist should have the right to
had
a
drawing back to the designer and say, "there's the mill; go make it..."

A little cleverness in the design can save a world of time (and cost) in
the
making...

Jerry

Mill choreography
 

I give my Engineering Machine Design students a short stint on the lathe
and the mill. Sure calms down the exotic nature of the designs!!!

And when they cay that the project MUST have something done on the CNC,
I say 'sure, but it's your responsibility to schedule the 12 to 20 hours
of open shop time to get up to speed on the Haas' About 1 in 10 bites
the bullet and I wind up with a budding machinist.

Tom Gardner wrote:
I did 18 mill operations in less than 2 hours including set-up time. This
by changing the way I do my drawings and visualizing all the operations with
the thoughts of reducing set-ups, minimizing tool changes, laying out the
tools and parts and figuring the correct order of events. With my old BP
and methods I guess this would have taken close to two days! And, every
operation was within two thousandths. Think/cut!

So, after all that outrageous productivity, I took a little nap at my desk!

Mill choreography
 

Harold,

Having worked from prints for what seems my entire life, it wasn't uncommon
for me to redraw (on scratch paper) and re-dimension parts so they were
meaningful in the way they'd be made. No changes were introduced, just
dimensions provided in a way that was useful.

My early engineering education happened just before CAD took over
completely. It existed, but our colleges had not yet ripped out all of
their drafting machines. As a result of that, I learned graphical
methods from books that probably had their first several printings in
Sanskrit. My descriptive geometry class started with a grinning
instructor saying "... all but one of these guys are dead" - referring
to the author. He of course was not taking joy in their demise, but
emphasizing how long the book had been in print.

Ok, so the book was ancient. However, we were clearly being taught how
to pass the buck on responsibility for mistakes. Over-dimensioning
introduces opportunities to get something wrong, so it is strongly
discouraged (IMHO) to let the other guy/company be the one who absorbs
the cost of any mistakes.


By working to nominal
dimensions at all times, you are able to use any portion of a machined piece
as the datum point. That's important when you start changing reference
points.

Understood. I ran into this just yesterday, having taken ten thou too
much off of something. The good news is that I picked a good dimension
for the mistake, but it lead me to have to start thinking about what
could/should and must not move as a result. Basically the parts are
rectangles with holes near the corners and a window (weight reduction)
inboard of the holes. The hole spacing has to match another part, so I
left it alone, and slid the window back ten thou in the affected direction.

One could argue that I should simply eye-ball the window, but the next
parts won't be so forgiving, and I (clearlyg) need the practice
holding tolerances. So, I try to build what I design down to a thou or
two, and use common sense in what I scrap. Of course, I made the
mistake on a stack of five plates, and after all other block dimensions
were correct - too much time and metal to toss over a matter of pride.

As for how I blew it, I had noted I was about 0.050" from final size, so
the plan was to take 0.020 twice and then measure again. I was
flycutting a stack, which is not the best way to hold tolerances on my
mill-drill, but if I stay on top of it, it works. Perhaps my real
mistake was to be emailing and making phone calls between cuts, but
somewhere either something slipped or I made a cut I forgot about (I'm
starting to think that is what happened). At one point, I was expecting
to have to take off ten, but measured 20+ to go. I measured, looked for
burrs and chips, re-measured a couple of times. Shortly after that I
measured again and found it undersized.

Bill

Mill choreography
 

ABSOLUTELY!!! Let the engineer listen to the gripes from the assembly
workers in the break room

Heh, heh, true story: Years back, I worked in a boat store, sold a
particular brand of trailer that has a TERRIBLE tilt mechanism, had to
rework every one that we sold. I promised that if I ever got the chance
I'd tell the designer a thing or two (or 10!) A couple years later I was
interviewing for an mfg engineering job. We got to talking, guess who
had designed the offending part? I bit my tongue for at least 5 minutes.
I finally figured out how to politely say the design was c**p, he
allowed as how it was, asked how I would have changed it. I got the job.

Ecnerwal wrote:
In article ,
Nick Mueller wrote:

Wes wrote:

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.
I know that some companies punish stupid or hard to assemble constructions
an engineer did by sending him to the assembly line and letting him do the
work for at least one day.

A smart company (try and find one of those) would do it as S.O.P.,
regardless of design "good" or design "bad" - the opportunity to see
what went right and what wrong, and what thing the designer thought
would help that's irrelevant, and what thing the designer thought would
be easy that's hard - all these are important.

Mill choreography
 

Having worked from prints for what seems my entire life, it wasn't uncommon
for me to redraw (on scratch paper) and re-dimension parts so they were
meaningful in the way they'd be made. No changes were introduced, just
dimensions provided in a way that was useful. By working to nominal
dimensions at all times, you are able to use any portion of a machined piece
as the datum point. That's important when you start changing reference
points.

I taught a short class to a bunch of design engineers and techs. One
major point was to dimension the parts in the way they were going to be
inspected. Picture a 3 hole group where two of the holes were
dimensioned from one end of a 6' long tube with a sweep bend in the end,
the other hole from the other end. Since there were more dimensions
involved, it was a lot of math to get to the desired hole spacing. Why
not just dimension the parts as a group? It was easier to snap the lines
on the CAD system.

Some snot in the back mentioned that under geometric tolerancing, the
tolerances were not cumulative. My response: that's true but you better
have better inspection folk and way more training because they are going
to reject the parts.



Harold

Mill choreography
 

Tony wrote:
Thats where the Methods Engineer comes in. He/she bridges the gap
between the designer and the machinist.


And adds another opportunity to screw up the communication between
engineer's brain and finished object.

Mill choreography
 

Tony wrote:

"Jerry Foster" wrote in message
. net...

"Tom Gardner" wrote in message
...
I did 18 mill operations in less than 2 hours including set-up time.
This
by changing the way I do my drawings and visualizing all the
operations with the thoughts of reducing set-ups, minimizing tool
changes, laying out the tools and parts and figuring the correct
order of events. With my old BP and methods I guess this would
have taken close to two days! And, every operation was within two
thousandths. Think/cut! So, after all that outrageous productivity, I
took a little nap at
my desk!

I've long been of the opinion that a machinist should have the right
to hand
a
drawing back to the designer and say, "there's the mill; go make
it..." A little cleverness in the design can save a world of time (and
cost) in the
making...

Jerry

Fixed that confusing top-post for ya ...
Thats where the Methods Engineer comes in. He/she bridges the gap
between the designer and the machinist.


Bull**** , that's just another layer of insulation between the guy who
designs and the guy who does . Every designer needs some time in the real
world of doing , IMNSHO . (I build commercial millwork , you wouldn't
believe some of the idiocies architects can dream up !)
--

Snag aka OSG #1
'90 Ultra , "Strider"
The road goes on forever ...
none to one to reply

Mill choreography
 

"Lew Hartswick" wrote in message
...
Tom Gardner wrote:

I did 18 mill operations in less than 2 hours including set-up time.
This by changing the way I do my drawings and visualizing all the
operations with the thoughts of reducing set-ups, minimizing tool
changes, laying out the tools and parts and figuring the correct order of
events. With my old BP and methods I guess this would have taken close
to two days! And, every operation was within two thousandths.
Think/cut!

So, after all that outrageous productivity, I took a little nap at my
desk!
And just how much extra time did all that prep take? :-) :-)
...lew...

Just the mental part, everything else in the 2 hour window. I posted a
while ago about changing the way I do drawings, optimized for the DRO.

Mill choreography
 

Ecnerwal wrote:

and what thing the designer thought would
be easy that's hard - all these are important.

CATIA has a function that automatically (or not) finds out wether a part can
be assembled or not. And it plots the path and shows how the part has to be
tilted and turned. Interesting with dashboards that go into the body fully
pre-assembled.


Nick
--
The lowcost-DRO:
http://www.yadro.de

Mill choreography
 

On Oct 13, 9:04 am, Paul wrote:
Wes wrote:
"Jerry Foster" wrote:

A little cleverness in the design can save a world of time (and cost) in the
making...

I'm a firm believer that engineers should spend some time as apprentices
making the things they aspire to design.

Wes

And repairing them also....

Paul

--
-----------------------------------------
It's a Linux world....well, it oughta be.
-----------------------------------------

That is what my dad has said for years. He always wondered if the
engineer designing "X" ever actually had to repair it. When you have
to dissassemble an entire machine to access some medium/high wear item
it's frustrating. Particularly when you look at it and if the
designer would have made "this" little tweak it would be a simple job.

I have tried to keep that in mind as I have been in the design
environment.

JW