Rapid moves

Hello,

Need some advice on setting rapid moves.

I have old CNC router that is running version 2.6.11 for many years without any problems.
It uses 1.25mm screws, NEMA 17 motors, drivers with 1/8 step.
Scale is set to 1280 (200*8/1.25). Base Period is set to 50000 ns. Acceleration 200, Stepgen ACC 250.
For many years fast moves were limited to 14mm/sec (840mm/min) for each axis.
Anything more than this would create following error. I never bothered to fix this.

Now I opened the Following error from 1 to 100, changed base period to 35000.
Following Errors are gone and I can move X, Y or both up to 20 mm/sec in MDI mode.

But once I run the actual NC program, X or Y axis stalls on some rapid moves making loud buzzing noise, then picking up moves without any issues but at the incorrect place.
It works better at 18mm/sec than 20, but not 100%.

So I thought that my drivers may not give enough current.
I changed settings peak limits from 1.7 to 2.2 to 2.7A and saw no changes.
I switched from 4A 28V power supply to 8A – no changes.
I actually measured PS current and it never go above 0.9A.
Also tried 1/4 step and different driver – no improvement.

I was playing with base period – I can easily go down to 20000 and it makes no change.
At 19000 I am getting real time delay errors.
I tried a faster computer - same results.
I also changed both ACC values up and down – still same issue.

One thing I need to mention is that its failing moves that use calculated values.
Calculations are simple +/- using 2 – 3 parameters, nothing fancy.
I am running out of ideas, so I am looking for help.

I did not think about max stepper speed. I thought it can go over 1000 RPM
Changing screw on this machine is another option that was thinking about. Vendor is offering 8mm pitch replacement.

The only thing that might increase your top speed would be increasing the voltage to your drives and motors. (current should not be the limiting factor.) You need higher voltage to overcome the back EMF of the motors.

How high should I go with voltage?
Drivers are rated 42V.
The power supply I have can't go above 28V (24-28).
I have another 5V 5A power supply that I can add quickly in series to see if it will make a difference.

I did a quick test at 33.5V and was able to run at 20 mm/sec
But when I tried 22 mm/sec it failed.
I don't have power supply to go any higher, and really can't use this setup with two supplies permanently.
Unless someone can offer something else to try, I will stick with 18 mm/sec and 28.5V.
Thank you.

stepper RPM are limited on Voltige
12V around 160RPM
24V 220Rpm
and 36V MAX for Nema17 around 360RPM

but you shoudt increase your timing then the following error will disapear

can you upload the INI and HAL to get a look

BASE shoudt be set to 100k in INI on parport use
WHAT drivers are you using

you woudt benefitt some from the master as the interpreter is rewritten and gives you a better timing

Thank you for your comments:
If steppers are limited to 360 rpm, then all my efforts to run at 1000 RPM are pointless. I am surprised that I was able to get them running that high anyway.

but you shoudt increase your timing then the following error will disapear

I am not getting Following Errors, I have mentioned that I had these earlier, but this was resolved already, my issue is stall with buzzing noise at high speed.

BASE shoudt be set to 100k in INI on parport use

I disagree with this: period should be shorter than 1/(1280 * 20) sec or 39063ns. I am running at 30000
.

WHAT drivers are you using

currently I am testing with TB6600, but I tried few other drivers.
Results are all the same.

At this point I think I am all set, I will leave it as-is and may be replace screws with 8mm lead later on.