I have two JIGs which I run with two similar spec laptops. One laptop is slightly faster than the other, however whichever JIG the slightly slower laptop runs is incredibly slow, even when velocity and acceleration are turned up to stupid amounts. All the settings are the same on both laptops, does anyone have any idea why this is happening?

Laptops have around 1gb of RAM, dual 2GHz processors, and fresh wipe and install of XP

Attach the xml from both Laptops please.
Hood

Morning, here are the XML files


On another note, this guy seems to be describing the same problem as me http://www.cnczone.com/forums/mach-lathe/140829-cnc.html


Here is a video of our test equipment (just for fun, no useful information here) https://www.youtube.com/watch?v=q1GqtryA96s&feature=youtube

Ok that is strange, you have the following for fast laptop profile
Steps per 331   Velocity 1000
For the slow laptop you have
Steps per 331    Velocity 2000

I would expect the slow laptop to actually be faster if you are doing G0 moves.


Is the code identical?
Is it G0 moves or G1's?
Are the drives/motors etc identical?

Hood

Yes, even if I turn the velocity up to silly amounts on the slow laptop but it still runs the steppers motors at about 5% of the speed of the fast laptop.

The code is identical, at the moment I am just testing a few mm in each axis. The first code is

'x-4 y6
g28'

then I use

'x4 y-6
x-4 y6
m47
%'

for the rest of the day.

All drives & motors are identical

Thanks

Have a look on the diagnostics page.
What does the Time in Int and Frequency show on each computer?
Hood

Slow PC:
Time in Int - 3.3 jumps to 8 occasionally
Pulse Frequency 1400-1600

Fast PC:
Time in Int - 7.5 jumps to 14 occassionally
Pulse Frequency 12700-14000

Since this morning the rig run by the slow laptop isn't actually moving at all, when I touch the bed of the test rig I can feel the stepper motor jolting away, but the bed of the rig itself isn't actually moving.

Sorry missed that you had replied.
Ok that is not good, both are having problems pulsing correctly but the slow one especially. I do not recall what you have the kernel set too but the minimum is 25KHz,  so assuming that is what you have set, then that is what the frequency should show.

As you are probably aware Laptops are not recommended, or indeed supported by Artsoft, when using the parallel port. The reason is because they can be  very problematic due to the power saving features built in and it looks like this is what you are suffering from.

You could try looking in the BIOS for any power saving features or frequency throttles and turn them off however it is likely there will not be any such options.

If you cant find anything like that then you probably only have two options if you want to use Mach.
1. Use  desktop computers.
2. Get external controllers so you can use the laptops.




Hood