G41 with G03

[Rekd™]

Ron, I selected the line not the arc when chaining, and I use Enter/exit at midpoint in closed contours.

 

'Rekd

[gcode]

quote:

---

It's been a really bad couple of days and I think I'm not thinking clearly.

---

I knew something was wrong. Rekd the Destroyer

usually eats this stuff for breakfast

[Rekd™]

quote:

---

if not you need to make it better

---

Ron, you're absolutely right. I am trying to convince myself that there's really no good reason for me to be as upset as I am.

 

'Rekd

[crazy^millman]

Well the problem I always have with midpoint and not dyanmic is that it may the mid point of the chain but not the midpoint of a line and to me that always works better than hoping Mastercam will put it where you want. I always do this beucase it just never seem to put it in a logical place to me.

 

 

Well hope your day goes better and glad to see you are getting a handle on it.

[heeler]

Rekd,

 

In looking at this problem it appears to me that you are asking it to do a .025 radius at 90 deg. Your pocket walls are only .258 apart and with a .250 cutter you are trying to move .025 in a .008 opening. If you change the radius to .005 and use a perpenducular entry I think that it will work.

 

HTH

Glenn

[Tim Johnson]

on lead in / lead out turn ogg gouge check. that has fixed my problem in the past

[Tim Johnson]

I mean turn off gouge check

[Roger Martin from CNC Software]

Millman,

 

quote:

---

Correct me if I am wrong but you can have a G41 or G42 on the same line or a G40 on the same line as a G03 or G02. The only thing is that you need to have enough room to engage cutter comp is all. I wonder if there is a parameter on the Hass that doesn't allow this Rekd?

---

You're corrected

You cannot activate/deactivate comp. on a G02/G03 circular motion block. Not on HAAS, not on FADAL, not on FANUC (even though I've had people claim they could). Heidenhain... maybe there is a Heid model that can. The only time I've ever seen this work (succesfully) is on a Giddings&Lewis HMC with a Numeripath-8000 controller. A few years ago I was in a car mfg. facility (a 'Big 3' plant where they make special stuff) and they were telling me "Oh yeah, we can do that". I did not beleive them, and they proved me wrong!

[crazy^millman]

Yeah after thinking about it for a minute you are right I use to hand write all my moves above a part then plunge then do my tight moves then do a move out the trun off cutter comp. I really dont use it much so do really think about the way I did use to use it. I am gald you pointed that out and corrected my mistake.

[jenks]

CAUTION! What follows is a very wordy reply, but I really felt it was worth passing on since I learned all of this at Hard Knock University.

 

Upper case that I use is not yelling, just my way of describing a parameter that needs to be changed.

 

I was having the same problem with the HAAS code and it made me nuts. I was having to manually write all of the entry code. And, I was being yelled at by the operators on a daily basis. With my fragile ego I was ready to do serious harm to someone. I finally took the time to make a set of exercises to learn how to make cutter comp work every time.

 

The following is the stuff I learned, but as a warning, it is 2D level 1. I don't know if these tips would apply to 3D.

 

I know it would be better if I could post the parameter pages to the FTP, but I can't.

 

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

 

FOR A RECTANGLE POCKET:

As someone else mentioned,

1. Break a line in the middle and start your chain there.

 

2. I use LEAD IN/LEAD OUT.

 

3. I leave INFINITE LOOK AHEAD on.

 

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

 

FOR A CIRCLE TOOL PATH (not a contour)

This is my favorite

 

1. I change the ENTRY ANGLE to 0

 

2. ENTRY/EXIT arc is set 90

 

3. Check START AT CENTER

 

4. Check PERPENDICULAR ENTRY

 

5. Compensation is WEAR

 

6. Compensation is LEFT

 

I have found that it doesn't seem to matter what the cutter diameter is as long as it is smaller than the circle. I have used a cutter only 1/32" smaller than the circle and it always works.

 

It makes the prettiest little "D" shaped tool path you could ask for.

 

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

 

SLOT, with radius on the ends equal to the slot width. (the slot is wider than the cutter)

1. I break the right end radius in the middle

 

2. I put a point in the center of the slot (where the X and Y axii intersect)

 

3. LEAD IN/LEAD OUT is ON and set to PERPENDICULAR. I generally use 100%

 

4. COMPENSATION is set to "wear"

 

5. DIRECTION is set to "left"

 

6. Start your chain with the point, then pick the upper half of the radius. If there aren't any geometry problems it should go all the way around the slot.

[CNCme]

Good Day,

 

+1 again gcode

The ramp arc/line will not violate the pocket.

Actually this is a good thing...I believe

in ver. 4 it would not compensate, and If small enough, It would junk a part.( not visualy

noticable without zoom )

At least now It will cause an alarm and stop the program.(On the machine tool...G41 G3or G2 )

 

 

Tony G

Almost Employed Senior Programmer

N.E Massachusetts - Southern New Hampshire

_________________________________________

End mills and tooling are like The "AMMO"

And coolant and chips are like the enemy

Under your boots as you advance in the

Manufacturing Battle

--------------------------------------------------

[Chris Rizzo]

Sorry Rekd, I've been out of the shop most of the day.....but Roger hit it

quote:

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You cannot activate/deactivate comp. on a G02/G03 circular motion block. Not on HAAS,

---

HAAS will NOT turn cutter comp (41/42)on on an arc move (02/03) Lemme guess, alarm # 340 from machine, which ='s "GODdam ****ing What the ****" from you.

 

 

Good solutions there Jenks. I myself just make sure that I've got a liner move in my lead in/lead out..which of course executes first and allows 41/42 to turn on.. and THEN does the arc Lead in/out...

Hope you've got it beat now, Rekd...

[gcode]

I just downloaded the newest MPMASTER from this forum and posted Rekd's file. They have added

a "COMP ON ARC" warning and it works

[Jimmy Wakeford from Barefoot CNC]

Rekd,

 

If your geo allows then you can have post automatically add a line move perpendicular to the arc.

 

This is very dangerous though as you do not see it in backplot, and I would only add if I had some sort of nc simulation software

[Phil Orenstein]

Rekd,

I recall doing OD contours with cutter comp I would enter with a tangent lead-in to a line move and exiting, I would finish the final arc move with a tangent lead out and the an arc lead out. This worked on the Haas. For pockets, Jimmy may have the right idea to add a pepndicular line move or lead in.

 

Phil

[DavidB]

Hi all,

 

Just a thought i do an arc at 90 degress and a line perpendicular with the same value.

This way the start of the G41 G42 is actually the start of the arc centre.Nice for tight eraes.

 

Have a gr8 weekend all

[Fig sign]

I will not argue with no one , I only want to say that me this never happens and never will happen .

 

1 .

I mostly machine mold steel and hardened steel .

So I mostly never use the same tool for rough take -off and finish

2

If I use the same tool I prefer to use create additional final operation feature where I can

copy it needed ammount of times ,split geometry to big pockets ,medium sze and little ones and tweak enter eexit according to my taste .

3.Beeing a lazy man and having proved a couple of times that you can sometimes gouge a part with

a big enter/exit arc (in some circamstances ) I always give minimum appropriate enter exit and mostly only perpendicular line

4.if the ammount of pockets is little I use contour start -dynamic ,and if the ammount of pockets are big ,but they are not important I use compensation computer without line in out or perpendicular with minimum ammount .

In most cases I prefer to HAVE POCKET WITHOUT FINISH AND CONTOUR TOOLPATH FOR FINISH WHERE I CAN HAVE GOUGE CHECKING and other nice features that pocket lead in out lacks !

The mentioned above for pocket also relies for surface->pocket toolpath where sometimes bad lead in out policy can scrap a part .

In surface pocket if I use finish toolpath I use it mostly without lead in out and never have any problem

I want to say that Mastercam pocket toolpath is the best and safest to compare with other Cad-Cam I used ,but pocket toolpath is one of themost complex toolpathes and you can have a prob with any Cad-Cam in it .

 

Iskander teh simpleton

[cadcam]

Roge,r I have had students (more then one) that swear they have hand progammed Fadals with a CRC on a G2 or G3, I know for sure that Haas does not support this along with most controls.

 

isnt this why we now offer the comp above te cut.

this way you can get your first liner move for comp out side the geo then go for radail entry?

[Fig sign]

quote:

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Roge,r I have had students (more then one) that swear they have hand progammed Fadals with a CRC on a G2 or G3, I know for sure that Haas does not support this along with most controls.

---

+! .

I used to write it by hand and our post for Auramill was doing this also on OLD Fanuc 6 controller .

But the resulting move was not an arc ,it was ellipse ,sorta unpredictable ,IOW dangerous .

That`s may be one of the causes why many controllers simply do not support this feature .

And it doesn`t matter me much .

 

Iskander teh G40 is your best friend

[Mike Mattera - TFM]

I dont know of any control that will allow you to start comp on an arc. I've never seen one do it and I've been writting posts for almost 20 years. I actually take out the "pccomp" command from my arc commands in the post. because theres no reason to have it.

 

Comp will not be active for the "rough" part of the pocket because Mastercam is figuring out where to go. Comp will only be active on the finish cut if you select it with the check box.

So here's the key: make sure your lead in/out has a linear move at least 50-60% and the arc is about 55% with a sweep of 110 or 115 deg. This will give you a tear drop shape. and should work everytime.

 

Mike Mattera

[Fig sign]

Mick!

quote:

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I dont know of any control that will allow you to start comp on an arc. I've never seen one do it and I've been writting posts for almost 20 years. I actually take out the "pccomp" command from my arc commands in the post. because theres no reason to have it.

---

To enter with an arc is a bad idea ,but in some controllers it is possible !

I wrote on this controller by hand and I have a good memory ,especially because it was my first controller !

I don`t want to start the flame war ,I only want to say that compensation implementation and it`s limitations differs from controller to controller ,and it is a separate topic .

I agree that no need to enter from arc ,but Mastercam leaves this option !

Why ?

 

BTW ,today was more then 30 degrees Celcius , super hot and very dusty , I am heading to the pool .

Swimming like a battleship

 

[ 02-29-2004, 12:38 PM: Message edited by: Iskander teh Owl ]

[cadcam]

Well sense I am having people tell me this is possible on the Fadal, I guess I need to stop buy some time this week to Fadal and see if this is true. Then if you want I can follow-up with you folks if you like?

 

I usually follow the thought of always having a Leaner move first.

 

But after a few telling me they can with a Fadal I have to think twice and now check.

[CAM-mando]

Jay,

 

I would be interested in knowing the "rate" at which Comp is applied if the control does in fact support application of crc on an arc move. If comp is applied using a "linear" distribution (ie. moving from "no comp" to "full comp" at a uniform rate over the length of the arc move). If so this would certainly lead to Gouging at the contour entry point.

 

CAM

[Thad]

quote:

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You cannot activate/deactivate comp. on a G02/G03 circular motion block. Not on HAAS, not on FADAL, not on FANUC (even though I've had people claim they could).

---

A Fadal will comp correctly when using only an arc. Right, wrong, or whatever, it works. We've done it for years.

 

Thad

[milehighxr]

On 2/26/2004 at 9:04 AM, Roger Martin from CNC Software said:

Millman,

 

 

 

quote:

---

Correct me if I am wrong but you can have a G41 or G42 on the same line or a G40 on the same line as a G03 or G02. The only thing is that you need to have enough room to engage cutter comp is all. I wonder if there is a parameter on the Hass that doesn't allow this Rekd?

 

 

---

You're corrected

You cannot activate/deactivate comp. on a G02/G03 circular motion block. Not on HAAS, not on FADAL, not on FANUC (even though I've had people claim they could). Heidenhain... maybe there is a Heid model that can. The only time I've ever seen this work (succesfully) is on a Giddings&Lewis HMC with a Numeripath-8000 controller. A few years ago I was in a car mfg. facility (a 'Big 3' plant where they make special stuff) and they were telling me "Oh yeah, we can do that". I did not beleive them, and they proved me wrong!

 

I gotta call bullxxxx here. I've been spoiled by Hurcos FNC programming, I could circle terp bores, mill slots, or pockets with nearly too big tools for years using G41/G42 comp on an arc move. Machine did it no problem. Take the program and change ONLY my post(say to the Fadal format 2, or a Fanuc) and no issues. It runs fine(IIRC, we just got rid our Hurco cuz it was needing more work to keep running). The only time I ever recall having an issue is when I post it to the Haas. Then I have to fumblexxxx around with lead in/out, and then using comp in computer(why bother having comp in control if i can't xxxxing use it).

I really find it difficult to believe in 2017(soon 2018) that there isn't a good workaround, or setting for Haas that allows cut comp to be engaged on an arc. It shouldn't xxxxing matter when it gets turned on.