Re: upgrading conventional

--- In CAD_CAM_EDM_DRO@e..., ptmachine@z... wrote:

> Does anyone have any experience with the up grades of conventional
> bridgeports to cnc? I have a flung dung bridgeport wanna-B and am
> wondering if upgrading is cost effective. Also will it truly work?
> Thanks, Neal

As regards being cost effective the answer is no. At the moment you
have a manual clone valued at say $3,000.
Add ball screws, pressure oiling, a decent Z axis feed, controller,
drive cards and motors. Even from second hand sources this will cost
anything from $1,000 to $3,000, a lot more if new.
Add this to the value of your manual machine and it's standing you at
anywhere between $4,000 and $6,000.
Actual worth of the retrofitted machine though has decreased though
to possibly $1,000 to $2,000 as it's now special.
None of these figures takes into accout time spent on the conversion
as I'm assuming that it's a hobby deal.

OTOH there are quite a few older CNC mills out there, usually with
either broken controllers or just outdated ones that have no
commercial worth. I can't speak for the US but here in the UK we are
tripping over these all for less than 1K. Machine tool dealers don't
want them because as they are either not working or not competetive
so who's going to buy one ?

If you really want a CNC mill and you have the space, look for an old
CNC. If space is a problem, sell the clone and buy a dedicated CNC
machine.

John Stevenson
Nottingham, England.