X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from alnrmhc16.comcast.net ([204.127.225.96] verified) by logan.com (CommuniGate Pro SMTP 5.1.5) with ESMTP id 1803411 for flyrotary@lancaironline.net; Thu, 01 Feb 2007 00:22:14 -0500 Received-SPF: none receiver=logan.com; client-ip=204.127.225.96; envelope-from=n3773@comcast.net Received: from rv8 (c-24-21-141-28.hsd1.or.comcast.net[24.21.141.28]) by comcast.net (alnrmhc16) with SMTP id <20070201052107b1600471k0e>; Thu, 1 Feb 2007 05:21:27 +0000 Message-ID: <001601c745c0$d0cd47a0$1c8d1518@rv8> Reply-To: "kevin lane" From: "kevin lane" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: gantry mill Date: Wed, 31 Jan 2007 21:20:57 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01C7457D.B2AEB0D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C7457D.B2AEB0D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jarrett - the titanium bulkheads for a F-15 started out as a 4'x8'x2' = ingot. they had to keep flipping it over while carving away so that it = didn't curl. when completed I could pick up the entire bulkhead with = one hand. none of the cross-sections were over 1/4" thick. I believe = they had 7 axis capability. titanium would cut at 5"/minute, whereas AL = could run at 70". we didn't use punch cards (that was college for = me!), but memory was measured in "K", like wow, 640K! I remember = hearing that the machining files for an entire F-15 took ONE GIGABYTE! = wow, imagine that. now I have a 50 gig hard drive. 4 million a second?! that's like a measurement every 8 degrees for every = cutter head blade turning at 25,000rpm. we used to joke about carving a one piece titanium canoe on a weekend = when no one was watching. http://www.sailplanehomebuilders.com/whatmembersaredoing.htm http://www.glidersport.net/about3.html http://www.pure-flight.com/ and on and on..... ----- Original Message -----=20 From: Jarrett & Heidi Johnson=20 To: Rotary motors in aircraft=20 Sent: Wednesday, January 31, 2007 8:08 PM Subject: [FlyRotary] Re: gantry mill No Kevin I wasn't aware, I'll have to go do some 'googlein' and check = it out. CNC has come a long way from the good ol' days of punch cards = and reel tapes :-) While its nothing in comparison to McDonnell, the = control I'm using on my machine runs at over 4Mhz per axis, that doesn't = sound like much when we have comp's running in the Ghz but, thats 4 = MILLION resolved position calculations and movement commands per = second.The tool will pass through 12 million resolved points per second = at full rate [when runing 3 axis at full rate and can drive up to 6 axis = at this rate if desired] I don't ever plan to run it that fast or to = that high of a command rate as its not needed in my case. As you'd = stated machining a huge titanium bulkhead would need a higher = performance system which can hit these resolutions and stop if an error = is found. I have no idea what Titanium is worth, but I'm sure I don't = want to have to foot the bill for a buggered up part :-). The gantry on = my mill isn't that heavy, its only about 3/4 ton but that was enough :-) = moving stuff like that around in your own shop w/ little to no heavy = lifting gear can be a challange for sure. A twin gantry mill would sure = be a site to see, I can't imagine writing the code for that, even w/ a = proper CAM. It's always exciting to hear of others who have done the = same thing and had success. Thanks! Jarrett ----- Original Message -----=20 From: kevin lane=20 To: Rotary motors in aircraft=20 Sent: Wednesday, January 31, 2007 8:50 PM Subject: [FlyRotary] gantry mill Jarret - when I worked at McDonnell-Douglas they had a twin gantry = mill. the bed was like 40', but the newer fighters had no pieces over = 15' so they added another mill. the gantries were huge, weighing many = tons. a secondary, independent computer would run while parts were = being milled, checking for any errors (not good on say titanium = bulkheads that take 2 months to mill). if it detected an error it could = shut the gantry down within less than thousandths of an inch. they told = me that it sounded like an explosion when all that tonnage hit the wall. = these machines had footings the volume of a 2 car garage. I was in the home built soaring club for a while. there was a man = building a plug doing exactly what you outlined. he was connected with = a university and used their equipment. maybe his plane is the = "lighthawk" I believe? he was proud of his ability to produce many = parts that all fit to tight tolerances. I didn't know if you were aware = of this project. kevin -------------------------------------------------------------------------= --- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.17/661 - Release Date: = 1/30/2007 11:30 PM ------=_NextPart_000_000D_01C7457D.B2AEB0D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Jarrett - the titanium bulkheads for a = F-15=20 started out as a 4'x8'x2' ingot.  they had to keep flipping it over = while=20 carving away so that it didn't curl.  when completed I could pick = up the=20 entire bulkhead with one hand.  none of the cross-sections were = over 1/4"=20 thick.  I believe they had 7 axis capability.  titanium would = cut at=20 5"/minute, whereas AL could run at 70".   we didn't use punch cards = (that=20 was college for me!), but memory was measured in "K", like wow, = 640K!  I=20 remember hearing that the machining files for an entire F-15 took ONE=20 GIGABYTE!  wow, imagine that.  now I have a 50 gig hard=20 drive.
4 million a second?! that's like a = measurement=20 every 8 degrees for every cutter head blade turning at = 25,000rpm.
we used to joke about carving a one = piece=20 titanium canoe on a weekend when no one was watching.
htt= p://www.sailplanehomebuilders.com/whatmembersaredoing.htm
http://www.glidersport.ne= t/about3.html
http://www.pure-flight.com/ = ; =20 and on and on.....
----- Original Message -----
From:=20 Jarrett=20 & Heidi Johnson
Sent: Wednesday, January 31, = 2007 8:08=20 PM
Subject: [FlyRotary] Re: gantry = mill

No Kevin I wasn't aware, I'll have to = go do some=20 'googlein' and check it out.  CNC has come a long way from the = good ol'=20 days of punch cards and reel tapes :-) While its nothing in comparison = to=20 McDonnell,  the control I'm using on my machine runs at over 4Mhz = per=20 axis, that doesn't sound like much when we have comp's running in = the Ghz=20 but, thats 4 MILLION resolved position calculations and movement=20 commands per second.The tool will pass through 12 million resolved = points=20 per second at full rate [when runing 3 axis at full rate and can drive = up to 6=20 axis at this rate if desired] I don't ever plan to run it that = fast or to=20 that high of a command rate as its not needed in my case. As you'd = stated=20 machining a huge titanium bulkhead would need a higher performance = system=20 which can hit these resolutions and stop if an error is found. I have = no idea=20 what Titanium is worth, but I'm sure I don't want to have to foot = the=20 bill for a buggered up part :-). The gantry on my mill isn't that = heavy, its=20 only about 3/4 ton but that was enough :-) moving stuff like that = around in=20 your own shop w/ little to no heavy lifting gear can be a challange = for sure.=20 A twin gantry mill would sure be a site to see, I can't imagine = writing the=20 code for that, even w/ a proper CAM. It's always exciting to hear of = others=20 who have done the same thing and had success.
 
Thanks!
Jarrett
 
 
----- Original Message -----
From:=20 kevin = lane=20
To: Rotary motors in = aircraft=20
Sent: Wednesday, January 31, = 2007 8:50=20 PM
Subject: [FlyRotary] gantry = mill

Jarret - when I worked at = McDonnell-Douglas=20 they had a twin gantry mill.  the bed was like 40', but the = newer=20 fighters had no pieces over 15' so they added another mill.  = the=20 gantries were huge, weighing many tons.  a secondary, = independent=20 computer would run while parts were being milled, checking for any = errors=20 (not good on say titanium bulkheads that take 2 months to = mill).  if it=20 detected an error it could shut the gantry down within less than = thousandths=20 of an inch.  they told me that it sounded like an explosion = when all=20 that tonnage hit the wall.  these machines had footings the = volume of a=20 2 car garage.
I was in the home built soaring = club for a=20 while.  there was a man building a plug doing exactly what you=20 outlined.  he was connected with a university and used their=20 equipment.  maybe his plane is the "lighthawk" I believe?  = he was=20 proud of his ability to produce many parts that all fit to tight=20 tolerances.  I didn't know if you were aware of this=20 project.   kevin

No virus found in this incoming message.
Checked by AVG = Free=20 Edition.
Version: 7.5.432 / Virus Database: 268.17.17/661 - = Release Date:=20 1/30/2007 11:30 PM
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