Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: compositepro on November 26, 2006, 02:15:30 PM

Title: 25khz maximum
Post by: compositepro on November 26, 2006, 02:15:30 PM
whats the relevance of 25khz

i read there are two settings 25khz and 45 khz am i wrong

drivertestnever goesabove 24khz
Title: Re: 25khz maximum
Post by: Hood on November 26, 2006, 02:44:50 PM
25, 35 and 45KHz is the pulserates you can have, if you have a large amount of steps per unit you may not be able to move your motors at their max velocity if you have it set to 25KHz as the pulsrate will be less than the max of your motors. As an example, if you have a step per unit of 1000 and a velocity of 2500mm/min you would need a pulse rate of 1000 x (2500/60) = 41,666Hz, if you set the pulse rate to 25KHz the max velocity you would be able to achieve would be 25,000/1000 x 60 = 1500mm/min.

 Hope I have my sums right ;)

Hood
 
Title: Re: 25khz maximum
Post by: Hood on November 26, 2006, 02:51:48 PM
Oh also I see your saying your test never goes above 24KHz, this could be showing that your computer is a borderline case for running Mach3, could be wrong but mine certainly shows 25KHz and slightly over.
Hood
Title: Re: 25khz maximum
Post by: compositepro on November 26, 2006, 03:22:53 PM
thanks for that i found out also im only running demo

hardware is not really a problem its a 3ghz quad xeon workstation(i do lots of cad design)
Title: Re: 25khz maximum
Post by: Hood on November 26, 2006, 03:29:23 PM
OK well I know the demo is limited to 25KHz so that may be the cause, out of curiosity how does the driver test look?
Hood
Title: Re: 25khz maximum
Post by: compositepro on November 27, 2006, 12:28:24 PM
driver test says 23782 does driver test test in 35khz and 45khz mode

does the demo do mach 4

im puzzled if i was to buy a license as my gcode is way more than 1000 line limit

do i buy a license for mach 4 im looking into getting grex

plus the new pc has a kentsfield processor and there arent many boards that have a parralel port

Title: Re: 25khz maximum
Post by: Chaoticone on November 27, 2006, 12:46:28 PM
The demo will only do 25KHz. Licensed will do 45KHz. ;D

A licenses for Mach is a Licenses for Mach,1, 2, or 3  ;D

Mach 4 has been replaced by Mach 3 with the G100 plug in.

I think you will have to have a parallel port. I don't know of another way. That's not to say their isn't though.
Title: Re: 25khz maximum
Post by: compositepro on November 27, 2006, 03:18:25 PM
i just heard the grex uses usb or eternet

thats why i was asking
Title: Re: 25khz maximum
Post by: chad on November 27, 2006, 05:39:56 PM
The grex uses Ethernet. At this time a licence file for mach three will remove the 1000 line limit for the grex also. When the grex is out of beta there will be a upgrade price. I don't think it will be to bad like an extra $50 or so ( don't quote me on that ).

The 25khz or 45khz is only an issue if you have high count encoders or really high gearing, or both. This basically just allows a faster pulse stream to come out of the parallel port. This also has no bearing on the grex. The grex is capable of 4mhz.

Chad