Who knows CNC equipment well?

[LukeZero]

Cross post from chat:

I just bought a Bridgeport vertical mill (vintage 1984) with a CNC package on it that has "lost its mind" in the Z axis. The quill has, in the past, gone to the full, highest position and stayed there, or gone down and broken the tool off in the workpiece. It sounds like the encoder for the Z axis is faulty, so that it doesn't know where it is in relation to the table.

Also, it has been so long since I've written any programs in M-code- does anyone have an old textbook from their tool and die apprenticeship days?

[redcorn]

An origin offset may still be active.
Perhaps MDI a G49 or G53 depending upon the control mght help.


Post up more info and I can assist.

G and M code is pretty easy.
Try to shareware Bobcad.
It is a cheap, yet fairly decent CAM package for 2 D camming and toolpath.

Keep us posted
john

[LukeZero]

OK, more information. Its not as old as I thought. Vintage 1994, not 1984. Has Bridgeport Boss XT control package. Just got it moved today, tomorrow I'll get it into place and wired up. Then begin to figure out how bad the Z axis really is.

[redcorn]

I am in Indy, so a roadtrip is not out of the question

[sk8salomon]

i'm not sure on older machines like that but newer ones usually have a z-axis hard stop that would prevent slamming the spindle nose into the fixture or getting stuck top side. i think i have an old book from college i'll dig up and see if its worth sending.

[LukeZero]

Originally Posted by sk8salomon

i'm not sure on older machines like that but newer ones usually have a z-axis hard stop that would prevent slamming the spindle nose into the fixture or getting stuck top side. i think i have an old book from college i'll dig up and see if its worth sending.

An old book might be just the ticket for an old machine. If you think it's worth sending (assuming you can find it)- I'll pay for the shipping.

[sk8salomon]

ok, i'll check. just moved recently so a lot of crap is still in boxes. redcorn's advice about an offset value may be the ticket. usually, there are tool offsets & work offsets on a machine. the work offsets are the contact points on the fixture, say a machine vise or jig (z=zero). tool offsets are programmed as well on most CNC machines so that you can't make programming screwups and plow a drill or endmill into something and fawk stuff up. say, you have a 50mm length endmill in the spindle, you tell the machine how long the tool is and it won't let you overtravel the tool. but your machine may not have both, not sure, i'm used to large multitool machining centers.

[LukeZero]

Finally got some pictures taken of the new mill...

[LukeZero]

and the old I already had...

[sk8salomon]

man, i would love to have one of those old machines. i would make chips all day for no reason just to have fun! i found that programming book but it wouldn't help you more than the interweb would. did you ever get the problem fixed?

[LukeZero]

Yes- i moved the home switch for the Z axis so that it homes itself without going too far. I only moved it about .050" but it has made all the difference in the world. I also changed the monitor since the original one was so blurry- I couldn't read the menus.

I am learning Rhino so that I can draw parts in it, then export toolpaths with RhinoCAM and start making parts. It's coming slowly, but its moving nonetheless.

[Doug_S]

You might try Index and talk with Dan. He's very knowledeable about CNC's and a heck of a nice guy. From the conversations that I've had with him, if it doesn't know something, he'll tell you and refer you to someone who knows.