[Eggo von Eggo]

Control is mounted on a Gildemeister NC lathe.

Am running into trouble with the "conversational" programmin, specifically the longitudinal roughing cycles.

Am boring .875" dia bore 4" deep, with boring bar that is nominally .05" undersize of the bore.

The "retract" move in the cycle will ram the backside of the bar into the far side of the bore.

Any suggestions of how to remedy this at the control?

Thanks

[joe1970]

drill a 3/4 inch hole and check the retract amount i.e. tthe amount the bar moves in x minus to clear prior cut I would use a 5/8/ carbide boring bar(given the 4 inch depth)for rigidity. Retract only .03 and rapid infront of piece. I have only delt with heidenhiem control once years ago. You should be able to progam this easily.

[Eggo von Eggo]

The problem isn't a tool selection one -- that's been taken care of. The problem is the retract.

The retract seems to be some sort of default value that can't be altered, or if it can, I can't seem to find the option to control it.

I'm not referring to G-code programming, but the onboard conversational programming.

[Bear]

Eggo
try telling control you are using a bigger bar(od)
control will recal. retract amt
Bear

[Eggo von Eggo]

Bear --

The only tools that I can define that include a diameter are listed as "boring tools", but for all intents and purposes, are drills/reamers. There's no way to define any cutter geometry other than diameter and chisel tip angle.

If you wanted to "cheat" and define a boring bar as a drill/reamer, it would only be any good for straight boring -- anything with a complicated taper or contour would be thrown off by the lack of accurate geometry (including corner rads).

Just on a lark, I tried using a drill-style tool to do some test boring in a straight bore.

Even though I'd defined the tool as being .875 dia, the pre-drilled hole to be .870, and the first radial depth of cut to be .005 (bringing the bore to .885 after the first pass), the control *still* rammed the boring bar into the back side of the bore on the retract.

The only significant difference (that I could see) between using a "turning tool" and a (incorrectly named) "boring tool" was that the boring tool performed an angled retract (X and Z simultaneous), while the turning tool retracted in X first and then in Z.

Thoughts?

[Daninwyoming]

It sounds like the tool radius compensation might be set to the wrong side. RL or RR (G41 or G42)

[maktiel]

I know this is an old post but, I've ran across a similar situation on 4190 and 3190 Heidenhain controls on a Guildemeister lathe. Using the G820 or G890 cycles my boring bar was trying to bore all the way to the center-line crashing the back of my bar. If I try to give it an X-Limit in the cycle it's a Maximum X-Limit not a Miniumum. The simplest workaround I've found is to lie to the machine and under the stock defination, define it as tube stock with the center hole the minimum bore size you want.

The other fix only works with the finish cycle. Give your G890 an H4 (I think) which will prevent it from doing any retraction at all. Then you can give it your own retraction move.

[GMMTB]

Just ran across this old post but I currently own a Gildemeister CTX 410 lathe with a Heidenhain 4290 control and used to have a lathe with the 4110 control (Great control I might add for a canned cycle lathe). The approach and retract in the cycles are controlled by a parameter setting. It is easily changed. I don't remember the exact procedure for the 4110 but for the 4290 you log on in service mode and call up the parameter from a list and a window opens up with a fill in the blank dialog on distances you want the cycles to use. Default I believe is .118 or 3 mm which is way too much when boring small i.d. holes. I changed my pull off to .02 which is fine for most occasions.

Gary M.

[aerogar]

Only have used heid's on interact mills, but for very small moves I sometimes had to use an m97. Usually solved the problem. Don't know if it will work on a lathe though.