Makino A51 "Read Ahead"

[RDEMIDON]

I am trying to run a program using Iscars HEM milling on a Makino A51. The machine reads that the program says F250. but it actually only runs about F90. The machine has run linear cuts before at feeds above F250. so I know it works. I think the problem is that the machine only reads about 4 lines ahead. Does anyone know how to change the parameter so I can make the read ahead be more than 4 lines? Thanks for your help.

[?Mark]

Try putting the G8P1 before the first feed line and see a difference. G8P0 to turn it off. Works on our A77.

If the moves are short, then there are accelerate/decelerate issues that come into place and machine may never reach programmed speeds.

hth

[Jon @ NOWHERE]

Do you have super g.i. turned off? If it is enabled, depending on which one you have turned on, it adjusts the feed rates in curves and what not to turn out a better part. We have 3 A51's so I will check with our maintenance to see if there is a parameter that controls "look ahead".

[Tony35]

on our a71 pro 3 control

G5P10000 turns it on G5P0 turns it off

i would flip on SGI if you got it

HTH

[RDEMIDON]

I will try the G8P1 right now.

 

As far as the SGI, I'm not sure if we have it or if it's on. How can I tell?

 

Thanks all.

[Tony35]

try in the program after G43

M251

G5P10000

G5P0

[Jon @ NOWHERE]

If you have a pro 5 control it should be listed at the top of the screen, it will be either M250, M251, M252, or M255. Not sure how it is for other pro controls, all of ours are pro 5.

 

M250 (High-Accuracy Mode)

 

 

M251 (High-Performance Mode)

 

 

M252 (Ultra-High Accuracy Mode)

 

 

M255 (Radical Mode)

[RDEMIDON]

I tryied the

 

M251

G5P1000

 

It gave me an alarm for improper G code.

 

I tryed just using the M251 and it still ran with the Feed around F90.

 

Also my control is a Pro 3.

[Jon @ NOWHERE]

Do you know what options you have turned on in your machine? You may have to contact Makino and let them know what you are trying to do.

 

We have a pro 3 on our A55 but I am in a catia training class right now so I can't go down and look at it.

[Tony35]

sounds like no SGI then

[Redfire427]

M255 (Radical Mode)

 

I have not heard of ths mode before. Is it specific to horizontals? How is it different than M250, M251 & M252?

 

Carmen

[Tony35]

on the pro 3 control the machine is in M255 when its first turned on

from what i understand is it will clip corners more unlike M252

[Redfire427]

Got it. I'll have to look that one up. We have 4 Makino verticals of different specs ( Pro 3 & Pro 5 ) but I have never seen that M-code before.

[Jon @ NOWHERE]

 

This is how it is explained in the manual I have. Apparently it is faster than M251, but the accuracy goes down. So it may be more useful in a roughing program that leaves adequate cleanup stock to overcome any inaccuracies.

[Tony35]

i have tried all of the M codes and really didnt see a big difference at least for the work we do

i generally rough with M251 & finish with M252 or M250 depending on the job

[Jon @ NOWHERE]

Same here, we use M251 for just about everything and M250 for a few 4th axis contouring toolpaths.

[Tony35]

ever use M253 for B axis contours?

i just remembered i never tried M254 (super gi mode)

[Jon @ NOWHERE]

No I haven't tried M253, it is listed as G.I./S.G.I. Special Mode in the book I have. Is that just for 4th/5th axis contours? What does it do differently?

[Tony35]

this it what it says in the book

"used when performing contouring with an additional axis and priority is machining accuracy"

my take on it is it helps the B axis "look ahead" for accel/decel

[Redfire427]

 

This is how it is explained in the manual I have. Apparently it is faster than M251, but the accuracy goes down. So it may be more useful in a roughing program that leaves adequate cleanup stock to overcome any inaccuracies.

 

That is very interesting. I have taken the Die/Mold training at Makino and this mode was never discussed, mind you, that was 7 years ago. We do have a brand new F5 Makino so I will have to take a look and see if this M-code is valid.

 

To the folks that question the differences between the modes............there is a huge difference between a program running in M251 and the exact same program running in M252.

 

PS. M250 does not do anything for rotary work. It only works on XYZ moves. There are a different set of M-codes for rotary work being M253, M257, M258.

 

Carmen

[Tony35]

i will say M252 is slower but you get great results

[Redfire427]

I tried the M255 on the new Makino F5 vertical and there is no M-code function. The code must be specific to horizontals or certain equipment. Honestly, I cannot imagine our machines being any faster or more responsive than what we get when using M251 for roughing.

[Tony35]

i wonder if on certain machines M255 is a "sgi off" code?????

our a71 fires up in M255

[Jon @ NOWHERE]

Its possible it is another option to buy.

[Tony35]

maybe not sure i know we have our a61 set to fire up in M255 and its a pro 5 control