jerky moves

[stoj]

hi all i1m new here and new to cnc to please be easy on me

it seems jerky on arcs i do have the cv setting on is this software issue? or code?


small clip

"http://www.youtube.com/watch?v=CBYm9AAmdN0"]IMG_0375.MOV - YouTube

[timberman]

Hi There
It is code if it was our machine
We would use XA2P for a curve & Xl2P for a straight.
You should have 1 start point & stay down all the time on a curve.
Hope this is of some use
Timberman

[stoj]

hi, many thanks for your reply

[stoj]

hi, im at the point were i scratching my head
please some help
ok using aspire just created some simple circles not cutting nothing just air i have tried the proceeser of all the g codes still terrible i dont want to attempt to cut anything as it will probbally break my cutter i have tried quick engrave it seems the bigger the circle the worse i set it to run 1500mm and its so slow on bigger circles and it sounds like the motors are going to stop
its very jerky or looks like it vibrating very fast lines are very smooth
any help please?
if you need any clips i can get some up
i brought the machine second hand but like new so i have not bult it i am new to all this and trying to learn as much as i can

[ger21]

Can you post your .xml file?

Or tell me what all the CV settings are set to?

[stoj]

ok spent few hrs late last night clicking a few buttons that i read on internet
under my settings tab in mach 3 i had cv feed rate on i turned this off it seems alot better
i would like it if some one would just check my xml code to see if it all seems ok

thank you for your time guys

[ger21]

Can you .zip the .xml file and attach it?

[stoj]

attached xml file

[ger21]

The .xml looks OK, although I had to remove the space in the name for Mach3 to read it properly.

One thing I would do is set both the step and dir pulse widths to 2 or 3 in motor tuning.

ok using aspire just created some simple circles

The g-code in your video is a series of straight G1 move, and not an arc.

Turning off CV Feedrate and CV Distance should make it much better. Looks like you have them both off.
Generally, the only CV option you want to use is the CV Angle setting.

You may find for some circumstances that CV Feedrate and Distance are helpful, but you need a very good understanding of how they work, which will take a lot of trial and error testing. I just leave them off.

[ger21]

If you're using Aspire, you might want to fit arcs to your vectors before creating toolpaths. This will give you more efficient, and smoother running code.

[Ron Dunn]

... and make sure you're using an ARC post processor when you save your toolpath.

[stoj]

thanks for your help