4th axis configuration

Hi
I am doing quite a bit of 4 axis work these days but the feed rates are really slow. My system is a simple one generated with the stepconfig wizard. Is there a way to speed things up. From googling around I get the feeling that there is a problem integrating rotary moves with linear moves. Are there tweaks I can make in the ini file? are the new versions of LCNC better at this?
Any help gratefully received.

Hi

If you post your ini file we will be able to see what you are working with

regards

To answer your main point.

Coordinated moves involving more than one axis, are carried out at a speed and acceleration that the slowest axis can achieve, so as to have all axes complete the move simultaneously.

Rotary axes, often from their construction as well as their usage are generally slower than linear ones.
A coordinated move involving a rotary axis will be limited by the speed which that can achieve.

This is the nub of the problem and your leaway for increase in velocity and acceleration of the 4th axis may be limited

regards

Hi ArcEye
Thanx for taking the time.
My ini file should be attached
Aaron

You have probably pushed the rotary axis as far as you can.

The velocity and acceleration figures look eye watering compared to the linear ones, but they are per degree, which is very little actual movement and only takes 8.8 pulses.

That is the problem, if your X axis is limited to max 100units/sec, other than in isolated A axis moves, I think your A axis will get limited to a similar amount even though the 2 do not equate.
Ignoring acceleration, at that rate the 4th axis would take 3.6 seconds to do one rotation, in which time the X axis could move 360mm!

Generally rotary moves are small increments, so it does not work too badly, but I would not be wanting to make too many barley twists in a hurry.

regards

So The only thing I can do is increase the speeds of the linear axis?

aaron wrote:

So The only thing I can do is increase the speeds of the linear axis?

I doubt you can, they are very high already, you are likely to get missed steps where the pulse train cannot keep up with the commanded speed.

You can try, your scale is quite low on X and Y so there may be a little scope. Your base-thread is reasonably high at 50K however.

The other addition is to code A positional moves seperately so they are not coordinated with linear ones.
Cutting moves of course cannot be helped by this

regards