continous cutting mode

[sjh]

Hi to all,
I need some help for Cincinnati milling machine.
When I use cad/cam file for curves (which are divided to many linear blocks) there is exact stop at the end of any block that produce shocks and vibrations.
Use of G64 in program could not solve the problem.
What should I do for having smooth transition from one block to other?
Thanks
sjh

[mike_Kilroy]

Originally Posted by sjh Hi to all, I need some help for Cincinnati milling machine. When I use cad/cam file for curves (which are divided to many linear blocks) there is exact stop at the end of any block that produce shocks and vibrations. Use of G64 in program could not solve the problem. What should I do for having smooth transition from one block to other? Thanks sjh

Maybe your title was too ambiguous for the folks who know answer to look? I am NOT a programmer, but have had to help inexperienced programmers on occassion solve problems like this, including this one.... was on router cutter for holes in 18 wheeler sidings they made... they too had a cad->cnc program that made circles with linear small moves. I showed them how to remove all say 20 small linear moves and just keep the last one with its end point, and change the move type from linear to circular - IIRC it was a G code change? and added the radius or something - which was info in the 20 lines removed anyway - like first move data or something. Anyway, they went from jerking the machine apart to 4x faster hole cutting smoothly.

Yes, it was a pain for them to modify each program as it was made, but from then on they could reuse it and not have to modify anymore....

I also believe there are G codes or something to turn on something a lot of folks call "blending?" that helps blend the linear moves together if you don't want to fix it with circles.

Perhaps this will get someone who really knows what they are talking about to help you!

[hmtr]

You never mentioned what kind of control you had. On the 850/850sx/950 controls, you want to use a G61 statement. The 2100 control has a table you can define for the selectable acc/dec profiles. A lot of times it's never defined, and I also believe it's an option.

The 850/850sx controls will default to G60 mode on every colon block. The 950 control had a comm data to choose to default to a 60/61.

[anand76767]

delete the value in the parameters which contain the exact stop.
in fanuc 16 m parameter no 5440 is used for uni-direction movement maka the value zero , this means exact stop will not operate.

[sjh]

hi,
it is a Cincinnati milacron (Arrow 750) and has its own controller (not fanuc).
I tested many Gcodes but there is one of these 2 conditioins :
G105 (high speed machining) : in the end of any block(with G1) there is a shock(like exact stop)
G106 (high speed machining off) : shocks are very lower than G105 but in any block feed rate is very low and non constant.
the following G codes are tested: G64, G61, G06(conditions are a little better),..
When the machine is running with G2 or G3 movement is very smooth.
I checked the Machine parameters but I can't find anything about exact stop or similar.

[mmckell]

Originally Posted by sjh Hi to all, When I use cad/cam file for curves (which are divided to many linear blocks) there is exact stop at the end of any block that produce shocks and vibrations. sjh

hello
I'm all self taught at this stuff but when I first got my CAM package, I was seeing the same problem. there should be a setting in you CAM to set linear segment lengths. mine was set to .1 - once I changed it to .001 the problem was gone (I work in metric)and the cuts were a lot smoother and no shocks. No "disco ball" effect on the machined part either.
I've also tweaked the post a bit with the post editor in the CAM package but the biggest change came when I changed the segment length.
Downfall - the programs become huge and the A2100 control will only run in "continuous load mode" - if the machine loses power... you have to start back at the beginning.(i hate it when that happens)

don't know for sure if this is your problem but...
hope this helps

Mac

[scudzuki]

If G105 turns high speed machining mode on and G106 turns it off, you have a Control Techniques FNC control.

In my experience G105 helps when profiling, transitions are noisier but there is no dwell mark from the motion pausing between blocks.

I keep the surface speed at 35 IPM or lower and it works okay. Remember that the cell phone in your pocket has 1000 times the processing power of that CT control. It has its limitations. Your servo tuning may be off, too.

I ensure that arcs are described as circular interpolated moves using cut arc fitting in my CAM whenever possible.

Joe