I am sorry for the late answer (4 years later) but I think it might be interesting for biesse cnc owners:
The problem is not about acceleration on the Z axis. I had the same issue on a Biesse Rover 23 a Biesse Rover 322 and a Biesse Rover B.
In fact these machines can accelerate as fast in Z as in X and Y.
The real problem is that the machine slows down and stops for a short amount of time after each non tangential step (ie: after each line of code).
When you have toolpaths with a lot of small moves, your cnc will take a lot of time with this behaviour but you can change this with one instruction in the code!
Try to add G47 at the begining of the code, just after G71. With this instruction I was able to bring the time scaling factor from 4.0 down to 1.0, but the cnc becomes less accurate (if somebody has a solution for this...)
This quote is taken from the biesse xnc programmers reference book:
G46: Commands the axes to arrest upon movement end, for non-tangential steps, while maintaining the attainment of the target co-ordinates within the positioning tolerance. Reset by G47, G27, G28
The G46 instruction is the default behaviour of Biesse machines.
G47: Avoids arrest or slowing of the axes on sharp edges formed between non-tangential steps. Reset by G46, G27, G28
If you use this instruction, the machine will move at "constant speed" and it will reduce a lot the machining time, but it is less accurate.
Tomorrow I will try G27 and G28 instructions to see if I can find a compromise between accuracy and machining time
G27: Commands the axes to arrest upon movement end, for non-tangential steps, without waiting for the target co-ordinates to be reached, within positioning tolerance
G28: Commands the axes to slow down upon movement end, for non-tangential steps, function of the angle formed with the succesive step.
I think G28 could be really interesting... Will try it tomorrow.
You can change the Biesse Rover Arcs PP to use these instructions:
Replace this line:
- Code: Select all
"N10 G71 HC=1 LY=[YLENGTH] PLPZ=[ZLENGTH] PDM=0 PUOS=0 FIL=0 BLO=0 ACC=0 RUO=1 PRS=1 PRL=1 PPWQ=0.000 KA=256.000 LZ=[ZLENGTH] LX=[XLENGTH] "
- Code: Select all
"N10 G71 G47 HC=1 LY=[YLENGTH] PLPZ=[ZLENGTH] PDM=0 PUOS=0 FIL=0 BLO=0 ACC=0 RUO=1 PRS=1 PRL=1 PPWQ=0.000 KA=256.000 LZ=[ZLENGTH] LX=[XLENGTH] "
I hope this could help Biesse owners...