forum.cncdrive.com

I've puzzled over this several times and read the manual but still can't make much sense of these settings:

Linear addition length max.
Linear unify length max.

What results should I be seeing when I change either of these? Are the default settings of 1 and 2 appropriate for inch settings? I've seen many screenshots of people using metric settings and the default 1 and 2 is the same for them. Should I be changing these numbers to inch for better results (.0394 and .0787)?

Dan

There's no easy or one size fits all answer here.
The default settings of 1 and 2 are metric, so you probably want to change them.
The effect they have depends on what you are cutting. They mostly effect toolpaths with lots of very small G1 moves, like 3D carving. How fast you are moving can also have a large effect, as the slower you go, the more accurately the machine can follow the toolpath. Acceleration also comes into play here.

The best thing to do is to do some small sample tests with different settings, and see firsthand what effects they have.

That's exactly the kind of work I do primarily. Complex mold surfaces with large numbers of point to point moves. Okay I'll have to play around with it to see what it does. So far I have never changed those settings. I have noticed that in some instances when passing through a particularly dense cluster of small moves that the machine tends to 'bump' its way through (something that can be felt while resting a hand on the machine) and leaves a slightly inferior surface finish which I have never been able to overcome. Maybe this is what I'm looking for in these settings.

Thanks,
Dan

Hi. If you can find a good setting, could you show it here so I can choose a strategy for matching the settings on my machine? I was making a 3d relief, programmed in artсam, selecting a target speed of 3000 mm/min, but the machine would not accelerate above 2000 mm/min (even when I increased the F to 250% in UCCNC).
Unfortunately, artсam for 3d strategy uses a huge amount of linear moves, here's a sample code:

Code: Select all

X191.3436 Y240.4529 Z-10.0940
X191.2403 Y240.4976 Z-10.2320
X191.1370 Y240.5422 Z-10.5239
X191.0387 Y240.5844 Z-11.0466
X190.9234 Y240.6339 Z-11.9680
X190.9141 Y240.6379 Z-11.9762
X188.2018 Y241.7540 Z-11.9597
X185.4860 Y242.7833 Z-11.9611
X183.3330 Y243.5386 Z-11.9778
X183.3243 Y243.5415 Z-11.9627
X183.1506 Y243.6001 Z-10.7102
X183.0793 Y243.6241 Z-10.4067
X183.0033 Y243.6496 Z-10.2421
X182.8800 Y243.6908 Z-10.0691
X182.7109 Y243.7470 Z-9.9241
X182.4924 Y243.8192 Z-9.8061
X182.2416 Y243.9013 Z-9.7265
X181.9715 Y243.9890 Z-9.7133
X181.6894 Y244.0798 Z-9.7805
X181.5516 Y244.1238 Z-9.8378
X181.4138 Y244.1676 Z-9.9235

Thank you!

Try increasing the Max linear error a little, and see if it makes a difference. If not, then you are likely limited by your machine's acceleration.

Which accelerations are normal? I have 300 as it was after installing UCCNC, what numbers can I safely increase to? Here's a picture of the machine: https://www.dropbox.com/s/wv3zg28dhmu09 ... 4.jpg?dl=0 Assembled from 14mm boards, 1605 screw, 16 rails.

fixebr wrote:Which accelerations are normal?

You need to find out through trial and error what your machine is capable of.

ger21 wrote:You need to find out through trial and error what your machine is capable of.

I'm sorry, I didn't ask the question right. I haven't done machine tools before, this is my first. What are the signs that the machine is failing?