Re: Bridgeport CNC retrofit recommendations wanted.

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Kim Lux <lux@d...> wrote:

> On Tue, 2003-12-16 at 08:09, doug.rasmussen@c... wrote:
>
> <snip>
>
> > With a budget of 15K, IMO, you'd be far ahead by purchasing a

used

> > commercial machine. In that price range there's plenty

available

> > given the current state of the used machine tool market.
> >
> > The dedicated commercial controls of even 15 years ago generally
> > will be far ahead in functionality of the hobby-oriented

(EMC,etc)

> > PC controls.
>
> I highly disagree with this statement, on a number of fronts:
>
> a) *some* controllers, ie my version of TurboCNC, has everything a
> modern CNC controller has (and then some) and much, much more than

a 15

> year old controller has. For example, many 15 year old

controllers did

> not have hellical milling routines (ie G72/G73), decent on screen

code

> editors, etc. It is highly unlikely that an older controller

could be

> made to perform a rigid tapping operation, for example. 1988 was

15

> years ago. PCs were just beginning to have some power. The

controls on

> a 15 year old machine are likely to be quite limited.
>
> b) the control electronics on 15 year old machines are quite old

and

> subject to various problems. What does one do when a control card

quits

> on a 15 year old machine ? We just retrofitted a 13 year old

machine

> because the owner couldn't (or wouldn't) fix a failed operator

interface

> panel.
>
> c) the flexibility and power of a "source code available"

controller

> allows the owner to get the machine to do things the way he wants

it to,

> not the way the programmer *thought* it should work 15 years ago.
>
> Kim
>
>
> > --
> > Kim Lux <lux@d...>

Hi Kim,

First off, I didn't mean to suggest buying a machine that old, I was
only making the statement that I feel the commercial controls of
that age generally have more features than the current hobby PC
based
types. This is not a criticism of hobby controllers, you wouldn't
expect them to be the equals of the commercial controls that were
developed by groups of engineers over years.

My advice to the OP was based on my assumption that he was more
interested in machining than building a machine. And with a $15K
budget it's possible to buy a fairly newish machine and be making
parts tomorrow rather than piecing something together over the next
several months.

a. I don't know anything about TurboCNC. I think you're using it
on a lathe, right? Compare it to an Emco-Maier T1 control which is
over 15 years old. How many canned cycles do you have? Turning
cycle, face or longitudinal with tapers & finishing pass? Tapered
and face threading? Grooving, face & radial? CCR? Constant
surface speed? What's your rapid speed? How many tool & work
offsets? Do you have an operator panel or do you work off a
keyboard? Spindle load meter? Auto lube? Those are just a few
of the ways I'd compare the two, and keep in mind the T1 in it's day
was not a high end control.

b. Yes, older controls electronics will always be a problem.
Repairs can be expensive, but the expenses can be offset by the
productivity. I figure about $1000 a year in maintenance on each of
my controls.

c. Two of my controls have macro programming, so it is possible to
make them do things the way you want. I think I've only used the
feature a couple times out of curiosity. Another point, I don't
think most commercial controls were designed by programmers, maybe
implemented, but not designed. More likely designed by indivduals
who understood machining processes. On the other hand I think some
of the hobby controllers were desinged by people with little or no
machining experience.

Have you ever used a modern commercial control? If so, I don't
understand how you could make your arguments.

thanks,

Doug