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View Full Version : Giddings & Lewis, surface contact-sensing feature, Amazing why not today?



Old Hat
10-25-2014, 05:19 PM
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0CD0QFjAD&url=http%3A%2F%2Fwww.iamachinery.com%2Fbrochures%2 Fscans%2F0400.pdf&ei=1BFMVMjdJcukyASZwIKACg&usg=AFQjCNEt5Fwnc5ryVbZMA_Wkj-MJivPwFg

I used this feature on a Carlton 8" floor~bar.
I'm here to tell you it's a mind~blowing experience.

Can you picture ramming toward a die-shoe that weighs 3 tons with a 1/2-13 tap at full rapid?
How bout a 1/4-20 tap at full rapid? Remember 8" spindle... might weigh a half ton it's self.

All I needed was X & Y coordinates and a depth and a speed and a pitch.
And this was an old bar in 1999, when I used it.

Why not today?

macona
10-25-2014, 07:49 PM
We do, it is called probing.

Old Hat
10-25-2014, 09:07 PM
Point missed.

CNC 100%
No need to measure tool-lenght, no offsetting.
Simplified programming, and could run even out of a ATC magazine.

One-offs and proto's perfect appliction.
Load tools go to position pull the trigger.
No regard to quantify~ing surface locations.

Edwin Dirnbeck
10-25-2014, 09:40 PM
THIS SOUNDS FANTASTIC. I have never seen or heard of this. I dont know if this would work with todays super high speed rapids .Old time rapids were around 400 inches per minute, Now 1200 and up are common. Consider this ,when a rapid move is commanded to a certain point, the control take this into account and starts slowing down before it gets there. This hapens so seamlesly ,it appears like it is rapiding and bang it stops. With the system that you are talking about ,the control might not have time to stop smoothly. Just my thoughts. Do you remember how fast the rapids were on your machine. Thanks for sharing this interesting concept Edwin Dirnbeck

Doozer
10-25-2014, 09:49 PM
It seems they call it HydroSense.
Must detect hydraulic pressure spike when the tool hits the work.
Seems kinda simple enough. Why CNCs don't have this, I dunno.

--Doozer

Old Hat
10-25-2014, 10:28 PM
I can't be certain how fast the rapids were. This was 1998 or so.
And I was on big bars all the time back then. Maybe 200 IPM at best?
Respectable for an 8" spindle at any circus, then.

I also can't remember which was which, a Bar Man works with a Z & W axis, or a W & Z axis
or on a Bar with a "B~slide" the counter-axis to Z with the rotary table on it might be a Q axis.

I'm gonna say the quill was W, and the ram was Z, the quill was hydaulic, the Z was a DC driven axis.
I remember the quill stopping imperseptably at the point of contact and I'm gonna say that the Z-ram (DC servo'ed)
axis was simultainiously triggered with either the drilling cycle, or a rigid tapping cycle.

I'm sure this must have been the case because if registered taps were used in rigid holders
a replacement tap could be run into a tight hole tapped with a dull tap.
I don't see how this would have been possible in hydraulics.

OH, and yes with the G&L 8000 I seem to remember I could back up in any program
and search out a remerging point.

If I had this bar today,
I could do much of my work in 30 - 50 % less time.

A NOTE:
Fast and ultra past rapids are a fraudulent sell on large machinery.
Far more set-up time, and adjustment~time and tare-down time accrues on a job than chip-time.
And even scrutenising chip-time, rapiding aint the Lion's share. If it is you're a poor programer.
Forethought and plotting your your work is critical! Why subject your lead-screws to 500 / 800 / 1200IPM rapids.

I think Carlton of the G&L family called this simply Surface Sence.
I also can't remember the G-call to use it or if an M-call had to proceed it by a few blocks.

Supposedly this all was an offshoot of the highly refined valving and modulation acheived
at the pinnachel of the tracer (duplicator days.)

Old Hat
10-25-2014, 10:44 PM
My Kingdom for lack of a video-cam back then...... :(
My hair stood on end at full salute when I first let it send a 1/4-20 at that shoe like a torpedo.
I might have almost cried but I could not have in the presence of the dayMan.

macona
10-26-2014, 04:23 AM
Ball screws last a very long time even at high rapids, virtually every machine I worked on has had it's original screws in it. Heck, the Mag 1 we had at work can cut as fast as it could rapid, almost 2000ipm. I have seen it work and wish I could post video, it is amazing. Of course it has a 108hp, 33000 RPM spindle to keep up with that. That machine took 24-30 hours of machine time on a forging down to about 8.

I am not sure how there system worked, I am betting you can find the patents on it somewhere.

Old Hat
10-26-2014, 06:57 AM
I am not sure how there system worked, I am betting you can find the patents on it somewhere.

Mag is the re-incarnated Giddings and Lewis.
And has gone back into bankruptcy / restructuring.

Some of what allows for these insane rapids is the use of linear ways that are recirculating rollers not recirculating balls.
Now much heavier machinery can run with reduced friction losses asscociated with box-ways.
Also twin screws are more common now and share the force-loading.

The ball-screws now have a far coarser pitch which slows the rpm needed to reach these high rapid speeds.
Today's computing speeds are so much faster that slower-moving encoders / resolvers can read a finer vernier output than before.
And two or more trucks on one screw again share the force-loading.

Rendering work from solid blocks and forgings is a pursuit that has little in common with huge weldments.
The features of ultra high speed movement can actually be put to good use carving out airframe parts etc etc.
It's child'splay compared to the set-ups and positioning efforts it takes to do huge hollow, segmented, and chambered weldments.
>>>>Yes, I've done both<<<<

Like the one in ExacTech's video.
https://www.youtube.com/watch?v=8Q3xhyUkqM0

mister honey
10-26-2014, 08:56 AM
Mag is the re-incarnated Giddings and Lewis.
And has gone back into bankruptcy / restructuring.

Just to clarify...

MAG (Maxcor Acquisition Group) once owned Gidding & Lewis and Cincinnati, but today those entities are part of the French conglomerate Fives Machining Systems.

The MAG1 (a product of the Makino Aerospace Group) is a Makino 5-axis horizontal machining center, specifically for aluminum machining. Totally unrelated to MAG, the Maxcor Acquisition Group.

Mike

Old Hat
10-26-2014, 10:03 AM
Thank You.. Mike, that matters.
Even helps back up my point about high rapids applications too.

CarlByrns
10-26-2014, 10:21 AM
What era would that Giddings and Lewis brochure been from?

It looks like everybody bought their clothes from wherever Joe Friday got his :)

Old Hat
10-26-2014, 10:39 AM
60's ? Pretty much.
G&L actually were out in front of Cincinnati Rockford and Kearny & Trecker at times along the way.
The application of this technology that I used on a large floor-bar doesn't seem to surface any hits.

Forrest Addy
10-26-2014, 12:02 PM
We had an open side "planer" version of that same machine. It was big as in a lot of work capacity. maybe 4 x 12 ft. The rail was not adjustable You had to block the work up to it. The spindle ram dropped like a rock and stopped when it sensed the work - probably 100" a minute with a #6 tap sticking out. Drop clunk! and it was tapping following the lead. Scared you to death.

We did a lot of 70-30 copper nickel tube sheets on that machine. Each hole was spot drilled, rough drilled, bored wih a back tapered endmill, reamed, and two grooves cut into the bore and it held 0.0005 tolerances for hole size for thousands of holes.

We had an old driller, Orville Armstrong, whose specialty was drilling tube sheets. He was so consistant and reliable the boiler makers would borrow hime for drilling their tube sheets. He was a pleasant hard working guy who never screwed up. He was highly esteemed by his peers and management

The machine was a sensation and drew crowds at first. I was there rubbernecking when Army first came up to watch that G&L work a tube sheet averageing two minutes a hole. He shook his head and shambled off like he was crushed, obsolete. I think it may have caused him to retire.

Here's a company history of G&L from the perspective of the finance people who could care less about the nuts and bolts so long as tons of money could be accreted by controlling everything while understanding nothing.

http://www.fundinguniverse.com/company-histories/giddings-lewis-inc-history/

Old Hat
10-26-2014, 12:50 PM
Here's a company history of G&L from the perspective of the finance people who could care less about the nuts and bolts
so long as tons of money could be accreted by controlling everything while understanding nothing.

http://www.fundinguniverse.com/company-histories/giddings-lewis-inc-history/

My son calls them "econo-facists".... worse than ever now. I once saw a very large shuttle-bar do it's thing brand new.
The owner of the company came in every day drooling over it while it was being wrighted.
He watched it shift tables no faster than the older ones. He went gray and looked like he was gonna off himself.
All the huge stuff it could do mattered not. He never came to see it again.