Fw: [CAD_CAM_EDM_DRO] CNC bridgeport

Sorry guy's...my email server is burping again!
MC

----- Original Message -----
From: "Marcus and Eva" <implmex@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, November 30, 2003 9:40 AM
Subject: Re: [CAD_CAM_EDM_DRO] CNC bridgeport


> Hi Jessie:
> I agree with all you say about the versatility of turret mills like
the
> Bridgeport.
> They are an excellent compromise between the conflicting needs to be able
to
> tipped and tilted for screwy setups, and the requirement for rigidity when
> taking decent cuts.
> They are, in my opinion, a rather poor base for a CNC mill though (here
come
> the FLAMES!!!)
> The quill mounted Z axis is a dreadfully inefficient piece of work; the
> stroke's too short, the quill is hanging out way too far most of the time
> and flapping around, there's a single little bolt transmitting all the
> force...I could go on and on.
> Driving the knee instead is in some ways a bit better, but now every hole
> you peck drill has the knee plus the saddle and table, plus the job
humping
> up and down from here to eternity, and the guts of the elevating mechanism
> are not really up to it, unless heavily modified.
> Not only that, but the flex in the machine frame means you can't drill a
> big, deep hole without rubbing the side of the drill on the top corner of
> the hole once you get in a ways.(unlike drilling with the quill, where the
> drill follows the direction that the quill is pointing)
> The whole frame opens up like a too-skinny C-clamp, and you end up
trashing
> a whole lot of big drills, unless you take it real slow.
> Jobbing machining is NOT about taking it real slow!!!
> There's no enclosure...the coolant and chips go everywhere, and you can't
> control them like you can when milling manually, so your whole shop turns
> into a free-fire zone and then into a pigpen in moments.
> The super useful tilting head in manual mode becomes a huge liability for
> CNC, unless you CNC the quill, and do it in such a way that you can still
> tilt the head with it mounted.
> Even then, it's really only good for engraving on a job that you don't
want
> to set up on a sine plate...and how often do you think you are going to do
> that?
> If you don't put folding safety handles on the tables, you'll sooner or
> later take a slap in the n*ts, and the safety handles are a pain to use
> manually.
> Every time you go to grab a handle, it ain't there so you have to break
> concentration to go look for it.
> That messes up the rhythm of your work enough to be a real drag, and takes
> most of the pleasure out of using the machine.
>
> When I got into CNC I thought long and hard about this option too...I
> abandoned it because of these big liabilities, and also because I got the
> opportunity to spend half a year on a Milltronics with all of the
Bridgeport
> conversion features except the Y-Z plane knuckle on the head.
> That cured me fast, of any love for these kinds of machines, especially
> since there were a couple of Okumas and a Toshiba standing 50 feet away.
> While their drivers stood in comfort having a smoke, I was jumping around
> dodging the bullets and the spray, and I trashed more than one job when
the
> head shifted.
>
> If you're serious about CNC as a means to make a living, I wouldn't settle
> for anything less than a fully enclosed, toolchanger and coolant equipped
> bedmill.
> Trust me on this...you cannot be competitive without these features.
> If you're just hobbying around or picking up the odd job, you can get by
> with a pretty unsophisticated setup, but if you need it to keep the wolves
> from the door, a proper VMC is a "must have" in my opinion.
>
> In your words " I love the idea of having a manual machine that will
double
> for a CNC machine".
> You ain't gonna get that...what you'll get is a crappy CNC and a useless
> manual mill that you, yourself, so lovingly wrecked!!
> Do yourself a favour and get a decent VMC and a Bridgie for all the manual
> jobs.
> The pain of the lease payments hurts, but if this is supposed to be a
> business, it's a small price to pay for a huge gain in productivity.
> OK guys...you may now begin to flame!!!
> Cheers
>
> Marcus
>
>
>
>
>
> ----- Original Message -----
> From: "Jessie" <rebel307@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Saturday, November 29, 2003 6:15 PM
> Subject: [CAD_CAM_EDM_DRO] CNC bridgeport
>
>
> > when I was in tool&die tech in college I started to all but worship
> > the bridgeport mill. It just seem to be so versital and it stood by
> > me in my workplace even though the one I used at work had over .100
> > play in the lead screws. I am planning on starting my own job shop
> > and need CNC. I was looking in the microkinetics website for a
> > bridgeport CNC retrofit. I . Thats why I joined the group a
> > few minutes ago, I need to know a few things about the CNC retrofit
> > kit. Does the quill feed actually control the quill and not the
> > knee? and if so will the quill feed still be able to be controlled
> > by the handle we all are so accustomed to? I can program CNC in the
> > dark so making programs is as simple and drawing a stick figure to
> > me. The motor mounts, ball screws, and Z axis mounts run up to 3,235
> > $ from microkinetics, flashcutCNC offers the same as an option to
> > their retrofit for 4,995$. Does microkinetics offer the controller
> > and everything else, cause I couldnt find it one their site or the
> > 42M1150 steppers. I would rather have servos. I dont like the 695$
> > price on the motor mounts when I could probally make them myself for
> > way less then 100$. I dont know how the Z axis mount works cause I
> > have never seen a quill feed like that put on a manual bridgeport. I
> > downloaded the flashcut demo and I like it theiy controller connects
> > to a serial port on your computer versis the microkinetic controller
> > card. Sorry to make my first posting here so long but before I
> > invest that much money in something I wanna know what I am gitting,
> > thats why I hate shopping online,, cant see it,,, cant feel it. if
> > you have read this far,, thanks,,, if not, I guess you;ll never know.
> >
> >
> > Rebel
> >
> >
> >
> > Addresses:
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