Re: NEW member Suitable conversions?

> From: "Matt Shaver" <mshaver@...>
>
> > From: "Fred Smith" <imserv@...>
> Yep, you're right about this! I've never run a cnc lathe before, but I

think

> we/re going to have a problem here with the X offset. Since the EMC has
> mainly been used on mills it has a tool length (Z) and diameter (X & Y)

type

> tool table. I guess we could fudge the X offset by entering it as a tool
> radius and turning on compensation, but this seems awkward. This is one

(of

> several) reasons I'm eager to build an EMC controlled lathe so that these
> issues can get sorted out. My "fixture offset" idea was the best

workaround I

> could come up with. Another issue the programmer of this specific lathe

will

> have to deal with is not running into the unused tools still mounted on

the

> carriage. Tim Goldstein, if you're reading this, how do you deal with the

X

> offset issue when you run in lathe mode, or do you only run single tool
> programs?

A lathe control like the 5T (circa 1976) had just an X and a Z tool offset.
It did not do cutter comp. To do cutter comp on a lathe you need a third
register for tool nose radius, and an orientation to tell the controller the
direction of the tip(cut), so that it can tell how to offset the geometry
(ID, OD, profile, backturn, back bore, etc, 9 in all).

Most Gang tooled lathes have a tool block with a series of 1" holes every 2
inches, or a similar pattern, and the tools , especially for
drilling/tapping, etc are all on incremental centerlines. They are usually
set up with a short Z travel, as there is very little that can be done to
avoid tool-part interference between long boring bars and short turning
tools. My Pratt & Whitney has an 8" square turret, with a 5/8 shank turning
tool and a 1 " round holder on each of 3 sides. The 4th side has a gang
style holder for center drilling and drilling, also holds small boring bars.
It indexes under program control and uses air to actuate the indexes. I
have been programming this machine with either Bobcad or Vector since I
bought it in 1993.


Best Regards,

Fred Smith
IMService

imserv@...
Phone: 248-486-3600 or 800-386-1670
Fax:248-486-3698