hi.total ignorant to cnc but buying one

[jking]

Hi all.I want to learn cnc and want to put one in my shop to play and learn on.A relative works at a place and they are closing.They have this BP mill.

I am aware that it is old.On another board a guy said it wouldnt be too hard to change the drives and connect a computor and update it.I want to learn and dont want to spend a fortune for one of these.This has 3 axis which is a big plus.I will know Monday if this worked ok which he thought it did but will confirm.
Is this a stupid move to buy this to do a conversion or even run it the way it is?
What would be a fair price on this mill? I wont be doing anything for NASA so I dont need a super tight machine.Just want to mess around.I work in a job shop and have a small shop that I do work out of so I do know how to machine.Also am a good tinkerer but not a computer wiz nor electronics either but bro inlaw is. : )What do you think? Thanks Jim

[erd39030]

Well, it depends only in the price.

I always prefer machining centers than "converted" milling machines.
I got my machining center for $3000 .

If you are learning, I would recommend you to buy a machine with newer controller, with screen and text menus, so you can see all the information the machine is working with.

Something that bothers me, when using my machines, is not having a "go to" reference, so I can know at every step of my program where the machine is, and where it is moving to. Without that reference, I have to be sure that my program is ok before I run it.

Also, it is most useful to have a complete Z axis automatic movement. Once I put all the tools in the machining center and put their Z reference, I forget about them and focus on the program, because I know that all the tools can reach the piece of a given setup, the table will always be at the same distance, because all the head moves with the tool.

But for a knee mill, your automatic "Z" is smaller, and sometimes when you must to raise or lower the table in order to use a short tool and a longer one, in one program.

So, if its really cheap, go ahead and buy some fun.
But if you can find a machining center for the same price, better get the machining center, or buy/make an inexpensive cnc router, less rigid, but with the same characteristics of any CNC.

By the end of the day, the only thing you need is to learn in G code: How to make a line, how to make a circle or an arc, how to compesate for tool size, how to use feed and speed. Then to learn in how to make complex surfaces in a 3D CAD/CAM software and make it generate de G code.

[kritic]

Is this a Boss 4, 5 or what I had a couple of Boss 5"s probably will do ok for what you want to do. Are you going to be doing any off line programming on a cam system or straight up manual programming. I think parts are hard to come by on this machine. I know there is a transistor that tends to blow that controls the axis drive. I used to keep a bunch of spares. If the machine runs Id say its worth around 2,500.00 Just my .02 worth.

[jking]

its a boss 6.It is a 83 machine.Dont know if it runs ok or not.Stll trying to decide on a dollar amount that I want to spend on it.