Using "R" versus "I,J,K" with G2/G3 on Milltronics?

[Avs_Fan]

Hi All,

I'm hoping to get some opinions on which method is better &/or more reliable.

 

We've been using "R" for awhile now, without too many problems. However, yesterday I encountered a problem that I finally tracked down to using "R" instead of "I, J, K". I kept getting some gouging on a Surface Finish Parallel routine. Various filter settings did not help. Finally tried posting my file with some other posts, including MPMASTER.pst. They all were fine!? Further research showed me that all of those posts output "I, J, K", not "R", with G2 & G3.

 

Anyway, which is better for Milltronics with G2/G3, "I, J, K", or "R"?

[Matt Berube at Ferron Mold]

I don't know anything about your milltronics, but we had an incident with "R" in a Fanuc OM control. We were cutting a really big arc (30" dia) and it ended up oval by about .015

 

We've been using I & J ever since with no problems

[deeherk]

personally i like using i & j better...

dan

[drago]

I found that I,J,K is a lot less mistake prone then R. If your values for initial or final X and Y are not right G2/3 with R will still make an arc, while with I, J, K it will alarm out.

 

Might not be a big deal when you're using mastercam to post out a program, but since you're using mastercam to post it out, you're not saving any time or calculations by using R.

 

Therefore i don't see one logical reason to use R versus I,J,K in any CAM program

 

Just my $.02

[Mike Mattera - TFM]

If the arcoutput is set to 1, R can give you problems. It should be set to 2 (as shown below).

 

 

arcoutput : 2 #0 = IJK, 1 = R no sign, 2 = R signed neg. over 180

 

Mike Mattera

[35K chipper]

A program with R output will use less memory in your machine control. I,J,K is more reliable for me.

 

35K

[Jack Mitchell]

+1 on drago's comment; been there and done it more than once.

 

 

Regards, Jack

[Threept82]

The problem with using "R" is.

Machine will cut your radius but not necessarily where you want it. "I, J and K" tell the machine where the ctr of your radius is, "R" does not.

If the math doesn't work out correctly using the "I,J and K" way your machine should alarm out. With "R" machine could careless where to swing the Arc from it just swings it.

[Avs_Fan]

Wow, thanks for all the responses!

 

They answered my questions. I think this about covers it.

 

Now I have some changes to make to our Milltronics posts.

They were based on an older version of "MPCENT5.PST" that output "R".

(If it helps anyone else, the version of that post dated 5/28/2003 is set to output "I, J, K")

 

Thanks again!

[heeler]

If you output arc at quadrants, you won't have the issue of

 

quote:

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I don't know anything about your milltronics, but we had an incident with "R" in a Fanuc OM control. We were cutting a really big arc (30" dia) and it ended up oval by about .015

 

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I like to output r values because it helps me check the program is there is a problem with the part.

 

M2C

Glenn