Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Ed on February 09, 2008, 11:28:21 AM

Title: jerky servo Mach3
Post by: Ed on February 09, 2008, 11:28:21 AM

I have just built a new table and power supply. I'm using 320 gecko's . I have been up for days tyring to get this wright. The table runs perfect in jog mode. But when I run code that I run on my stepper table it is very jerky and misses steps. I hate to ask but could someone Please help tune these motors in mach3.
Thanks Ed

Title: Re: jerky servo Mach3
Post by: Hood on February 09, 2008, 11:40:16 AM

Make sure your Jog is set to 100%, could be that you have a slow Jog set up so that when you are tuning your motors it is not at your true rapid speed and as such when you are running the code it is exceding the limits.
 I dont have any experience with Geckos servos so cant help there I am afraid :(

Hood

Title: Re: jerky servo Mach3
Post by: Ed on February 09, 2008, 12:05:48 PM

My jog is at 100%. It will jog around at 100 units smooth but running code at as little as 6 units it jerks and misses step's.
Thanks Ed

Title: Re: jerky servo Mach3
Post by: Hood on February 09, 2008, 12:15:09 PM

If you write code with all G0 moves does it work smoothly?

Title: Re: jerky servo Mach3
Post by: Ed on February 09, 2008, 09:06:58 PM

I would have thought someone had ran across this. I changed my kernel speed from 25000 to 45000Hz and the table runs perfect. But I had my motors set to 100 velocity. My jog runs at 200 so I have to set velocity at 50. Now my table jogs at 100 units. Why is this is there some other setting in the motor that I'm not getting. Even though I'm very happy with my new table now its runs very smooth.
Thanks Ed

Title: Re: jerky servo Mach3
Post by: Hood on February 10, 2008, 04:20:51 AM

What version are you using?
Hood

Title: Re: jerky servo Mach3
Post by: Ed on February 10, 2008, 02:50:13 PM

The Newest one.
Ed

Title: Re: jerky servo Mach3
Post by: Hood on February 10, 2008, 05:55:04 PM

You mean the development version or the lockdown? If its the dev one try the lockdown.
Hood

Title: Re: jerky servo Mach3
Post by: Ed on February 11, 2008, 12:13:30 AM

This is what I'm using Mach3VersionR2.63. What causes the kernel speed to to affect the volicity speed. Now even if I which back to 25000Hz it only jogs at half the speed.
Thanks Ed

Title: Re: jerky servo Mach3
Post by: Hood on February 11, 2008, 02:26:01 AM

Ed
 Kernel speed will alter the velocity if you have your motors tuned for example near the max at 35KHz then turn down the Kernel you obviously wont be able to reach this speed. However yours seems kind of the opposite and I just dont have an answer apart from to try and re download and install again.
 If you attach your xml I can have a look and see if I can find a problem.
Hood

Title: Re: jerky servo Mach3
Post by: Ed on February 11, 2008, 11:46:29 AM

This is my xml file.
Thanks

Title: Re: jerky servo Mach3
Post by: Hood on February 11, 2008, 04:29:47 PM

Ed
looked through your xml and dont see anything wrong. Did notice you had different steps per unit for each axis though, is this correct?
Hood

Title: Re: jerky servo Mach3
Post by: Chip on February 11, 2008, 04:45:25 PM

Hi, Ed

Mach may be trying to adjust your vel/Accl. when your setting dif. kernel speed's back and forth, A re-start is req. after change and then a Re-tune of vel/Accl.

Did you use g00 moves or Shift + Arrow key to tune your Velocity & Acceleration settings ?

On the Program Run Screen what's your Feed-rate set to ?, Hit the TAB key, What's the Slow-Jog Rate set to ?

If thy aren't set to 100 then your tunning is probably way off.

It's volunteer's around hear for the most part.

Hope this Helps, Chip