Programming question

[powerfulp]

Hi,

 

I have a CNC programming question. I am pre-drilling a hole with a carbide drill for a long HSS drill which will follow. The HSS drill doesn't have thru-the-tool coolant capabilities and I wanted to save time by drilling as deep as I could with the carbide drill first. Anyway, I have to peck with the HSS drill, which I know is a G83 with a Q-value. My question is, how would you program this so the drill retracts all the way back to the R-plane of the solid carbide drill after each peck? Is there a way to do this in a canned-cycle, or am I going to have to program this point-by-point? Obviously, I'm trying to accomplish this without point-to-point programming.

 

Control is a Mitsubishi Meldas 500M.

 

Thanks for any help.

[CJep]

A G83 will return to the R plane if you're using a G99 with the canned cycle, if you want to send it back to the initial position (if your retract and clearance are different values) then you would need a G98.

[powerfulp]

Yes, that would be after the G80 is executed. I'm wondering is there a way to return to the initial R-plane in a canned cycle? So, say there is a deep c'bore of say 2.500" and I have to start my drilling at the end of the c'bore, but want to retract to the top of the c'bore between pecks. Can this be done without programming each and every move?

[CJep]

I'm wondering is there a way to return to the initial R-plane in a canned cycle? So, say there is a deep c'bore of say 2.500" and I have to start my drilling at the end of the c'bore, but want to retract to the top of the c'bore between pecks. Can this be done without programming each and every move?

 

Are you are trying to is send the drill to floor of the c-bore as a rapid move then start pecking, once completed rapid back to a position above the c-bore before moving to the next position?

 

To do that you will need a G98, activate clearance plane, set the retract a value above the floor of the c-bore, the top of stock is set as the floor of the c-bore and depth is set as the final depth.

 

N15 G28 Z0.

N20 T1 M06 ( 1/2 DRILL)

N25 G00 G17 G90 G54 A0. X-5.75 Y0. S1675 M03

N30 G43 H1 Z.5

N35 M08

N40 G94

N45 G98 G83 Z-3. R-1.375 Q.25 F16.5

N50 X-4.0659 Y-4.0659

N55 X0. Y-5.75

N60 X4.0659 Y-4.0659

N65 G80

N70 M09

N75 M05

N80 G91 G28 Z0.

N85 G28 Y0. A0.

N90 G90

N95 M30

%

[Slepydremr]

how would you program this so the drill retracts all the way back to the R-plane of the solid carbide drill after each peck?

 

We've run in to this problem occasionally. I'm sure the post could be setup to make it easier, but I don't believe you can do it with a canned cycle.

 

The few times I've had to do it I just used point to point tool path like you mentioned.

[JACK2ME]

I while ago I created a custom drill cycle that works for this problem. The problem with the G83 is that yes it will start inside the hole but it's going to rapid into the hole to the "R" position. By creating a custom drill cycle you can work around this.

[EX-wccprogrammer]

I wrote a custom peck drill cycle to retract almost all of the way out of a hole to clear the chips and allow coolant in. This keeps the drill tip in the hole so control is not lost. I can post partial code, if anyone needs it.

[EX-wccprogrammer]

Obvoiusly, there are some creative variables here, but this is what I did:

 

pdrlcst$		 #Custom drill cycles 8 - 19 (user option)
 if drillcyc$ = 12,	 #CHIP EVACUATION CYCLE
 [
 omitcycend = 1
 zabstemp = refht$ + drl_prm1$ - drl_sel_ref$
 zpecktemp = refht$ + drl_prm1$ - drl_sel_ref$
 zpeckclr = zpecktemp + peckclr$
 z$ = depth$
 zevac = refht$ + drl_prm3$ + drl_sel_tos$ - drl_sel_ref$
 pdrlcommonb
 pcout
 "G00 G90", pfxout, pfyout, e$
 *initht$, e$
 *refht$, e$
 "G01", *zpecktemp, *feed, e$
 "G00", *zevac, e$
 *zpeckclr, e$
 zpecktemp = zpecktemp - drl_prm4$
 zpeckclr = zpecktemp + peckclr$
 while zpecktemp > depth$,
 [
 "G01", *zpecktemp, feed, e$
 "G00", *zevac, e$
 *zpeckclr, e$
 zpecktemp = zpecktemp - drl_prm4$
 zpeckclr = zpecktemp + peckclr$
 ]
 "G01", pfzout, feed, e$
 "G00", *initht$, e$
 pcom_movea
 !x$, !y$
 ]

[Bill Henderson]

If your machine is capable of IJK instead of Q.

 

Pick your rapid plane as you did the for the first drill and use the decreasing peck. Make your first peck the distance of the first hole drilled. (I). then the decrease (j) and finally a peck value (k).

 

If (i) is 1.00 and you want to peck .05 the (j) would .950 and (k) is .05