Return-Path: Received: from mtiwmhc13.worldnet.att.net ([204.127.131.117] verified) by logan.com (CommuniGate Pro SMTP 4.1.5) with ESMTP id 2624383 for flyrotary@lancaironline.net; Sat, 04 Oct 2003 21:22:19 -0400 Received: from unknown (249.birmingham-03-04rs.al.dial-access.att.net[12.86.89.249]) by mtiwmhc13.worldnet.att.net (mtiwmhc13) with SMTP id <20031005012213113007mhoue>; Sun, 5 Oct 2003 01:22:13 +0000 Message-ID: <003301c38adb$9c62d6e0$f959560c@unknown> From: "Michael D. Callahan" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Mill Drill and Lathe Date: Sat, 4 Oct 2003 19:57:10 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0030_01C38AB1.B2789FC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0030_01C38AB1.B2789FC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageRusty, Just my $.02, but hold your horses here. If you want to get into the = machine tool end of things, the FIRST thing you want is a good lathe = that is at least 12x36". A lathe is the basis of all machine work, and = learning how to properly operate one is the best basis for learning = machine tools. With a nice milling attachment, the lathe basically converts into a = 3in1 machine as it can be used for turning, milling and drilling = operations. The milling and drilling are horizontal and it won't have = quite as much movement when milling. Now here's why you don't really = want this 3in1 machine. Ed, I don't mean to knock your new toy, but I had a little 3in1, a = Smithy 12x20 (basically the same machine as this one, but this one is a = LOT nicer). I was not at all impressed and kept it less than a year. It = was an OK little machine...if it's all you had. The lathe was by far the best feature, but it was awkward. Note the = feed crank is on the opposite end of the bed from the chuck, where you = do most of your work, and it has no means of rapid traversing like the = typical carriage handle. It takes forever to get to the other end of a = long piece of work. Not only that, this machine has (and mine had) no = quick-change gearbox. A real PITA when trying to make finishing cuts and = when threading. You have to manually remove and install different gears = to change the feed rate. Changing belt speeds was no fun, either. It required a couple of = wrenches and about ten minutes work to change the spindle speed. TOTALLY = unacceptable for lathe work. You HAVE to be able to change speeds = instantly unless you are set up for finish turning on a production run = of a constant diameter. This one is only a 22" bed. Trust me, it's too short. I would go at = least 36" if I only had one machine. I have a 9x20 Jet lathe, and it's = WAY too small to really do much with. This machine doesn't have any more = swing over the carriage and it is only two inches longer, but that huge = tailstock is going to eat all of that up. It'll probably end up 18" = between centers. (After I typed that last sentence the pic with the tape = showing 19" finished up;-)). Get the longest bed lathe you can find that = will fit in your shop. Very rarely will you use the entire capacity, but = you will see the wisdom in these words in days to come. The greatest flaw in this type of machine is the mill head. Note = that the mill head can be swung back out of the way when not needed. = Great idea!....but that means it is on an un-keyed round column...BAD = idea! Anytime the mill gets under load, or hangs up, the head will = rotate on that column. It will eat up work, break bits, and screw up = your set-ups. This was my primary dislike of the machine, other than the = fact the table was too small and didn't have power feed when milling. = Since this machine has two motors, you may at least get one power feed = axis (x) for milling. (I rigged one up using the lathe leadscrew and an = old Hamilton Beach electric mixer motor ..it was variable speed, too!) Note that the distance from the mill spindle nose to the table is = only about 9". You put a 2" long endmill in there, and a vise that is 4" = tall to hold stuff in, and you can't get anything of any size under = there. Same goes for the drill press. You put a Jacob's chuck on the = quill (3-4"), and a 1/2" drill bit that is 4" long and you have about 2" = to play with. Forget the vise, it won't even fit. This is not really a very heavy machine. It says 925 with cabinet. = The little thing I had was about 750, but it had only one motor, the = table was smaller, and the mill head didn't have as much reach. The = basic bed on my machine and this one look identical. The bigger and = heavier the machine, the greater its accuracy. This is going to sound = strange at first, but my huge 24"x72" 25hp American Pacemaker lathe at = the museum is MORE ACCURATE than a watchmakers lathe. It is SO big and = SO rigid that you can take 1/4" deep cuts in 3" cold roll steel and it = won't even leave a mark when you back up. Mass is everything in machine = tools, just the opposite of airplanes. This machine probably weighs = about 850lbs without the cabinet. The lightest mill I have is 1300, the = heaviest is about 4000. The Pacemaker lathe is 12,000lbs. The little = ancient 10x48" South Bend toolroom lathe at the museum weighs more than = this whole machine and cabinet. What you need to do first is get a nice big old quick-change lathe, = with a milling attachment, taper attachment, four-jaw and three-jaw = chucks, live and dead centers, steady rest, follow rest, and tailstock = (make sure it has one). That should cost about what this machine sells = for, an leaves you with the shipping money to buy extras (which you will = find by the millions as soon as you get into this stuff). You can then = buy a cheap import drill press (which will be just as good as the one on = this machine and have LOTS more room) and matching vise for a couple of = hundred bucks and start saving up a couple of grand for a good mill. = That 2K should get you a very nice 20yr old Bridgeport, which will be a = FAR better machine than ANYTHING with slanty eyes, and will be easier to = get parts and tooling for. There are CNC and DRO conversion kits out the = yang for the Bridgeports. DRO or CNC conversions will cost about the = same no matter what machine it is, this one or a Bridgeport. DRO is worth its weight in gold, and about that same price. You'll = spend $1000 on a good three axis setup. Increasing the size of the = components has VERY little effect on the cost, so don't worry if you ned = up with a Bridgeport that has a 50" table, it won't cost any more to DRO = than this thing. Unless you already know G code, or just get a big kick = out of playing with text-based computer commands, you will probably find = CNC to be pretty useless for the home shop. It will take MUCH longer to = write the program to make a part than it will take to just turn the = wheels and whip it out. On a maual machine with a decent DRO, you can = easily get under .0005" tolerances. Most low-end CNC like this stuff = will do good to get in the .001-.002 range. If you need four thousand = identical parts, CNC is WONDERFUL. If you need two, it's a waste of = time. I will be glad to help you find a nice lathe if you want me to. I = recently found a lathe for friend in PA, who is finishing an Exec helo. = I found him a hardly-used 20yr old variable-speed 5hp South Bend 14x50" = toolroom lathe with quick-change box, 3 and 4 jaw chucks, follow rest, = steady rest (roller type), collet holder, full set of 5C collets, taper = attachment, coolant system, quick change toolpost, Jacob's tailstock = chuck, and cabinet for about $3K. He had to drive about 250miles to get = it. Mike C. ------=_NextPart_000_0030_01C38AB1.B2789FC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Rusty,
    Just my $.02, but hold your = horses here. If=20 you want to get into the machine tool end of things, the FIRST thing you = want is=20 a good lathe that is at least 12x36". A lathe is the basis of all = machine work,=20 and learning how to properly operate one is the best basis for learning = machine=20 tools.
    With a nice milling attachment, = the lathe=20 basically converts into a 3in1 machine as it can be used for turning, = milling=20 and drilling operations. The milling and drilling are horizontal and it = won't=20 have quite as much movement when milling. Now here's why you don't = really want=20 this 3in1 machine.
    Ed, I don't mean to knock = your new=20 toy, but I had a little 3in1, a Smithy 12x20 (basically the same machine = as this=20 one, but this one is a LOT nicer). I was not at all impressed and kept = it less=20 than a year. It was an OK little machine...if it's all you=20 had.
    The lathe was by far the best = feature, but=20 it was awkward. Note the feed crank is on the opposite end of the = bed from=20 the chuck, where you do most of your work, and it has no means of = rapid=20 traversing like the typical carriage handle. It takes forever to get to = the=20 other end of a long piece of work. Not only that, this machine has = (and=20 mine had) no quick-change gearbox. A real PITA when trying to make = finishing=20 cuts and when threading. You have to manually remove and install = different gears=20 to change the feed rate.
    Changing belt speeds was no fun, = either. It=20 required a couple of wrenches and about ten minutes work to change the = spindle=20 speed. TOTALLY unacceptable for lathe work. You HAVE to be able to = change speeds=20 instantly unless you are set up for finish turning on a production = run of a=20 constant diameter.
    This one is only a 22" bed. Trust = me, it's=20 too short. I would go at least 36" if I only had one machine. I have a = 9x20 Jet=20 lathe, and it's WAY too small to really do much with. This machine = doesn't have=20 any more swing over the carriage and it is only two inches longer, = but that=20 huge tailstock is going to eat all of that up. It'll probably end up 18" = between=20 centers. (After I typed that last sentence the pic with the = tape showing=20 19" finished up;-)). Get the longest bed lathe you can find that will = fit in=20 your shop. Very rarely will you use the entire capacity, but you will = see the=20 wisdom in these words in days to come.
    The greatest flaw in this type of = machine=20 is the mill head. Note that the mill head can be swung back out of the = way when=20 not needed. Great idea!....but that means it is on an un-keyed round=20 column...BAD idea! Anytime the mill gets under load, or hangs up, the = head will=20 rotate on that column. It will eat up work, break bits, and screw up = your=20 set-ups. This was my primary dislike of the machine, other than the fact = the=20 table was too small and didn't have power feed when milling. Since this = machine=20 has two motors, you may at least get one power feed = axis (x) for=20 milling. (I rigged one up using the lathe leadscrew and an old = Hamilton=20 Beach electric mixer motor ..it was variable speed, too!)
    Note that the distance from the = mill=20 spindle nose to the table is only about 9". You put a 2" long endmill in = there,=20 and a vise that is 4" tall to hold stuff in, and you can't get anything = of any=20 size under there. Same goes for the drill press. You put a Jacob's chuck = on the=20 quill (3-4"), and a 1/2" drill bit that is 4" long and you have about 2" = to play=20 with. Forget the vise, it won't even fit.
    This is not really a very heavy = machine. It=20 says 925 with cabinet. The little thing I had was about 750, but it had = only one=20 motor, the table was smaller, and the mill head didn't have as much = reach.=20 The basic bed on my machine and this one look identical. The bigger and=20 heavier the machine, the greater its accuracy. This is going to = sound=20 strange at first, but my huge 24"x72" 25hp American Pacemaker lathe at = the=20 museum is MORE ACCURATE than a watchmakers lathe. It is SO big and = SO rigid=20 that you can take 1/4" deep cuts in 3" cold roll steel and it won't even = leave a=20 mark when you back up. Mass is everything in machine tools, just the = opposite of=20 airplanes. This machine probably weighs about 850lbs without the = cabinet. The=20 lightest mill I have is 1300, the heaviest is about 4000. The Pacemaker=20 lathe is 12,000lbs. The little ancient 10x48" South Bend toolroom = lathe at=20 the museum weighs more than this whole machine and cabinet.
    What you need to do first is get = a nice big=20 old quick-change lathe, with a milling attachment, taper attachment, = four-jaw=20 and three-jaw chucks, live and dead centers, steady rest, follow rest, = and=20 tailstock (make sure it has one). That should cost about what this = machine sells=20 for, an leaves you with the shipping money to buy extras (which you will = find by=20 the millions as soon as you get into this stuff). You can then buy a = cheap=20 import drill press (which will be just as good as the one on this = machine and=20 have LOTS more room) and matching vise for a couple of hundred bucks and = start=20 saving up a couple of grand for a good mill. That 2K should get you = a very=20 nice 20yr old Bridgeport, which will be a FAR better machine than = ANYTHING with=20 slanty eyes, and will be easier to get parts and tooling for. There are = CNC and=20 DRO conversion kits out the yang for the Bridgeports. DRO or CNC = conversions=20 will cost about the same no matter what machine it is, this one or a=20 Bridgeport.
    DRO is worth its weight in gold, = and about=20 that same price. You'll spend $1000 on a good three axis setup. = Increasing the=20 size of the components has VERY little effect on the cost, so don't = worry if you=20 ned up with a Bridgeport that has a 50" table, it won't cost any more to = DRO=20 than this thing. Unless you already know G code, or just get a big kick = out of=20 playing with text-based computer commands, you will probably find CNC to = be=20 pretty useless for the home shop. It will take MUCH longer to write the = program=20 to make a part than it will take to just turn the wheels and whip it = out. On a=20 maual machine with a decent DRO, you can easily get under .0005" = tolerances.=20 Most low-end CNC like this stuff will do good to get in the .001-.002 = range. If=20 you need four thousand identical parts, CNC is WONDERFUL. If you = need two,=20 it's a waste of time.
    I will be glad to help you find a = nice=20 lathe if you want me to. I recently found a lathe for friend in PA, who = is=20 finishing an Exec helo. I found him a hardly-used 20yr old = variable-speed 5hp=20 South Bend 14x50" toolroom lathe with quick-change box, 3 and 4 jaw = chucks,=20 follow rest, steady rest (roller type), collet holder, full set of 5C = collets,=20 taper attachment, coolant system, quick change toolpost, Jacob's = tailstock=20 chuck, and cabinet for about $3K. He had to drive about 250miles to get=20 it.  Mike C.
   
------=_NextPart_000_0030_01C38AB1.B2789FC0--