Hello Guest it is November 27, 2021, 09:47:45 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - mikep_95133

Pages: « 1 2 3 4 5 6 »
My x and y axis are set to 20,000 pulses per inch. This is why I needed a faster computer that can handle a faster kernel.

1. Kernel=25khz, vel=135ipm, accel=1 the velocity slider is at 100%.

2. Kernel=45khz, vel=135ipm, accel=1 the velocity slider is at 100%.

3. Kernel=60khz, vel=135ipm, accel=1 the velocity slider is at 75%.

4. Kernel=65khz, vel=135ipm, accel=1 the velocity slider is at 66%

5. Kernel=75khz, vel=135ipm, accel=1 the velocity slider is at 55%.

6. Kernel=100khz, vel=135ipm, accel=1 the velocity slider is at 45%.

So I have to apologize for being wrong about my slider position earlier in this thread!!

Right now my accel is set around 1-2 as i recall. It's 3 stories down stairs. So I'm replicating my system settings on it's twin computer upstairs.

20,000 pulses per inch uses up a lot of cycles. So I was pretty lucky to get 135ipm out of the old pentium III 800mhz machine. But the machine won't go any faster at 2.4ghz. In fact, it actually skips slightly more steps if the kernel is set higher than 45khz, if I leave all of the motor settings the same. This is why I think the scope needs to be applied to the hardware to see if there is a mismatch in timing between the step and direction pulses. Or maybe my PS2501 opto board on the parallel port is the bottle neck.



How does a 15m/min @ 2500mm/sec/sec grab you? (that's 590 ipm @ 98 in/s/s) ;D and that's steppers on a 25KHz kernel. It'll actually do quite a lot more both in vel and accel but it gets a bit scary. It's a router but it'll snap cast iron G clamps if they get in its way.


Ian, you set the bar very high!! I'm thrilled! What size is your table/gantry? My table is a 42" wide cast iron Bridgeport mill table. So it's heavy.

Have any of you looked at the video of mine in action? Does it look sluggish? It's cutting air using code for a spiral cut pocket. It's set to 135ipm. I don't remember what the acceleration is set to.


No, the velocity slider is not even close to being maxed. I don't use it. I have always adjusted my max feed rates manually by changing the acceleration and feed rate individually. I could experiment with it. The acceleration has to stay under 2.0 to not miss pulses. I have gone as high as 10 for accel. Just looses pulses.

Do you think a 2.4ghz core 2 duo processor would really become unstable at higher than 45khz? My last pc was just a lowly PIII at 800mhz and it handled 45khz for years on end. These 2 comparisons alone show me it really isn't the pc.

200ipm on 25khz is great. I have zero experience with steppers. Mine is a servo.

Thanks Rich. Understood. Has anyone ever hit 200ipm for example??

I'd just like to know what others have achieved as a max feed rate while cutting air. I don't care if their hardware is different from mine.

After finding Mr. Cockrum's site, I'll take my isolated scope to the shop and start finding the weakest link as I posted earlier. My BOB uses NEC 2501 optos.  The data sheet looks slow to me. My amplifier boards have a 6n137 opto. Much faster.


Here is a video of the mill at 135ipm cutting a pocket in the air.


I found this guys's cnc site. His ideas for debug of the parallel port are just what I needed. I will bring my scope downstairs and get started. http://cockrum.net/cnc.html


The motors are dc servo. I have run them at 75v for 12 years. The power supply is variable from 0-200vdc. I did raise them from 75v to 90v. That made them stiffer, but not faster.


Sorry I left those details out. The pentium III could only go to 45khz. The new pc can go to 100khz but it skips pulses until I lower it to 45khz. Anything higher than 45khz just misses too many pulses.


This past week I 'upgraded' my pentium III 800mhz machine with a built in parallel port, to a core 2 duo 2.4ghz machine with a built in parallel port. The pentium could hit 135ipm with accel at 1 and have no pulses dropped. The new to me core 2 duo, and only hit 135ipm with accel at 1.5 and no dropped pulses.

Why did I not get a least a double in speed with the computer update.

All of this cutting air in a straight line.


The subject line says it all. I was testing for maximum ipm on my system. I raised the kernel speed one selection at a time while also bumping the ipm. Then I jumped to 100khz and now Mach3 locks up at the end of the screen loading, every time. Ii have to hit the reset button on my 800mhz pc to escape.

Is there a file in the Mach3 folder that I can go into and edit to bring the kernel setting down to say, 45khz?

A reinstall did not work as it keeps all of the old settings.


PS It's been a while since I've been around. Mach3 is now owned by NF? Is Art still around?

Works in progress / Re: New screen for Ascension 1000 users
« on: February 12, 2007, 08:28:28 PM »
What kills me is that Real Draw has some limitations that I thought were fairly significant. But it was very easy because of the video tutorials and the fact that it is a simple program. I already own Paint Shop Pro. It's so much more powerful that I can't figure out how to do the insets and things that make Real Draw so useful.

My RD guest license is about to expire too.


Pages: « 1 2 3 4 5 6 »