[acannell]

I think my requirements are:

-Used to save money
-Full 3 axis (no knee mills with 2 axis CNC and a manual quill)
-Automatic tool changer with at least 8 tools
-Enough rigidity to hold 0.001" tolerance at 50ipm, 0.150" DOC full slot in 6061 with no chatter and excellent finish. If it can do that, Im pretty sure it will be able to do whatever else I need to do any any material I will need to do it on.
-Fully enclosed or capable of easily being fully enclosed for cleanliness
-Able to have a coolant system
-18" x 12" x 12" working envelope (i.e. I could machine any edge on that size cube)
-Will fit in the space of a car (so I can use up one of the car spaces in my two car garage)
-Enough reliability to make production quantities of parts (i.e. 100 aluminum intake manifold flanges a day, for instance.)

My experience is sort of odd. At home I use a sherline CNC mill, at work I use a fadal VMC3016L. I definitely need something bigger, more rigid, and faster than the sherline, but I definitely dont need something as big as the fadal.

Please help! My budget is about $7000 max including freight, tax, initial fluids, start up costs..i.e. everything to be ready to go.

[DareBee]

Not going to happen.
Find yourself a 30 year old Fadal or similar is about it.

[Fastest1]

Better buy a lottery ticket.

[acannell]

Which requirements are making it not realistic?

Im open to a 30 year old machine.

What about this 1988 pratt and whitney?

Pratt Whitney Tape Mate CNC Vertical Mill Model B | eBay

[txcncman]

$7000 maybe?

[acannell]

$7000 maybe?

righttt....

so what specifications make it above $7000

[txcncman]

Enough rigidity to hold 0.001" tolerance at 50ipm, 0.150" DOC full slot in 6061 with no chatter and excellent finish

Enough reliability to make production quantities of parts

for 2

The main problem will just be being able to find any decent CNC mill for under $7000. I picked up a used Fadal TRM a couple of years ago for under $3000. But that is an exception, not the rule.

[acannell]

Enough rigidity to hold 0.001" tolerance at 50ipm, 0.150" DOC full slot in 6061 with no chatter and excellent finish

Enough reliability to make production quantities of parts

for 2

The main problem will just be being able to find any decent CNC mill for under $7000. I picked up a used Fadal TRM a couple of years ago for under $3000. But that is an exception, not the rule.

those are the two specs which are the most flexible..

lets say the production quantity is 10 parts a day, so pseudo production of simple parts with hour long tool paths at half load of the spindle and axis motors

and the machining spec..i just made that up as an ideal. whats more realistic at this price?

[awerby]

The problem you'll find with these old dinosaur VMCs is that they will have a hard time executing modern programs. The memory cache of a machine like that Pratt and Whitney is so small as to be almost nonexistent. That worked okay for programs that were written by hand, but the ones written by CAM programs tend to be a whole lot bigger. Even getting your programs into a machine like that can be difficult. Have you ever punched a program into paper tape? It's about as relevant to modern machining practice as player piano rolls are to modern music...

Andrew Werby
www.computersculpture.com

[acannell]

The problem you'll find with these old dinosaur VMCs is that they will have a hard time executing modern programs. The memory cache of a machine like that Pratt and Whitney is so small as to be almost nonexistent. That worked okay for programs that were written by hand, but the ones written by CAM programs tend to be a whole lot bigger. Even getting your programs into a machine like that can be difficult. Have you ever punched a program into paper tape? It's about as relevant to modern machining practice as player piano rolls are to modern music...

Andrew Werby
ComputerSculpture.com ? Home Page for Discount Hardware & Software

If thats what I have to deal with, Im okay with that. Im pretty sure I wont do anything beyond 2.5axis, and Im already used to tweaking toolpaths to have only as few poly lines as possible.

I figure they were making space shuttles and cars in the 80's, so the parts I want to make should transport to that time period okay.

The way I get nc files onto the 10 year old fadal is pretty primitive, just a serial port and a text upload. But it works okay. They had RS232 in the 80's so I dont see why it would be any different. And even if its tape only, I bet there are adapters or ways of getting around that.