Re: Total Novice - Not a Clue (where we all started!)

<SNIP> I figure I could do a milling machine for less providing I
didn't have to rebuild the

> machine first. I've always got my eyes open for a cheap manual

Bridgeport.</SNIP>

The most expensive and time consuming part of doing a large mill is
replacing the current leadscrews with ballscrews. There are kits out
there it do it but they can be pretty expensive and you still have to
do all of the installation. A lot of the guys have been able to find
older commercial CNC mills and use some or all of the components.
The price for a CNC Bridgeport with a busted controller is normally a
lot less than a manual Bridgport in the same condition and the
ballscrews are alread installed! If you can use the existing
steppers or servos (i.e. they are not burned up) there is another
expense avoided. Rumor has it that you can find used Bridgports or
other commercial CNC mills in the 1000 to 2000 range that are
mechanically in good shape.

I have a mill project under way (for over 18 months now) converting a
manual Gorton to CNC. It's got a variable speed head and power knee.
The only reason I did not buy a used CNC machine is that I was given
the Gorton for free. I traded for the DC servos to run it and have
access to other components from all the scrounging I did to build
other projects. The biggest job I have left is to mount the two zero
backlash ballscrews.

I won't have a lot of money (< 1000) in this retrofit but a lot of
man-hours are going to be invested before I see the first CNC part
made. I have had to keep the manual part functional to build all of
the custom plates and fittings for my other CNC tables.

A guy down the road just spent $25,000+ on a new CNC mill and is
struggling learning the CAM part of the equation. He came down and
looked at my servo driven torch table and just shook his head and
left. I didn't have the heart to tell him how little cash I have
tied up in any of my machines.