Re: Bridgeport MDI update

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:

> machines@n... wrote:
> > What is queer about it is that it only has one
> > drive card and it swaps this between axis as required.
>
> OH NO! That is a mess! These are called 1D or 1.5D machines. I

think

> you'll find this a very poor substitute for real 3 Axis CNC.
>
> > This means it
> > can do canned cycles like drilling, pockets, slotting, bolt

circles

> > etc and linear moves but it can't circular interpolate.
>
> It can't linear interpolate, either (unless it is parallel to an

axis).

>
> > When I found
> > this out before I bought it, It put me off but after realising

that

> > 90 % of my CNC work is only done in one axis at a time

Jon,
I looked carefully at this and after watching my full CNC machine do
3 consecutive jobs and other than going to the start position which
was a diagonal move ALL the other moves were linear one axis moves.
You have to realise that this is not my first and main CNC machine
but is one bought to take some of the work off the big Beaver. As Tim
has said in an earlier post it would convert very easy with 3 G320's
but it's time etc. This one is working, able to be quickly
programmmed at the console and can do the simple silly jobs plus some
manual work.
What I don't need at the moment is another project. I have one big
CNC mill, an Acton Powercentre with 10 x 54 table inside, halfway
through an Ahha refit. I'm trying to do this as simply as possible as
all I want is a CNC drill for sub contract work, - no milling.
The problem is every time I get onto it to do a bit more, another
rake of work comes through the door.
I won't begin to mention what's outside sheeted down <g>

> >I think the limited working area of 18" x 12" will be more of a

problem than the

> > linear axis moves.
>
> HAW! You think YOU'VE got problems. I'D DIE (well, almost) for 12

x 18"!

> I have expanded the X travel to about 28", but I can only get about
> 6.9" in Y right now. I need to hack off some interfering bits of

material

> in my CNC conversion to regain the full travel of the machine, then
> I'll have 9" of Y. This is on the old, round-ram Bridgeport, which
> had a smaller knee.
>

Jon,
I do a lot of long shaft type work and need a decent X axis more than
the Y. The 12" Y shouldn't be a problem but the 18" X could well be.
It just means I'll have to pick jobs for it. Some of the keyways can
be up to 32" long.
I wasn't actually moaning just passing a comment. When I was first
looking for a CNC I passed over a couple of Series 1's as not being
suitable for my job and went for the long bed Beaver. As a second
machine these limitations aren't as great.