Machsupport Forum

Mach Discussion => FAQs => Topic started by: fuzzbuzzuk on November 03, 2010, 08:29:01 PM

Title: spindle speed reads (-)
Post by: fuzzbuzzuk on November 03, 2010, 08:29:01 PM

I have recently set up my old denford orac lathe with mach3. All seems well apart from spindle speed. when the spindle starts up it reads it as a - figure. ie if i input m03s1000 in the mdi page it says the speed is -1000rpm. Ive changed debound settings and tried active low/high. Ive set up the spindle pulley to min 200 max 2100. I'm mega lost on this. anyone got any idea's??

Title: Re: spindle speed reads (-)
Post by: RICH on November 04, 2010, 06:50:44 AM

There was a problem with computer cpu's with a fast bus speed >2.1 Ghx which would cause the negative  spindle speed in the DRO.
That was fixed and you need to use version 3.042.33 and later.

RICH

Title: Re: spindle speed reads (-)
Post by: fuzzbuzzuk on November 04, 2010, 09:39:43 AM

ah yes i have updated mach to a newer version and it now reads the spindle speed.. but the problem i have now is it seems to read the spindle speed to fast and will not calibrate

Title: Re: spindle speed reads (-)
Post by: angel tech on November 04, 2010, 01:47:30 PM

are your speed readings low, or only go up to a certain speed

Title: Re: spindle speed reads (-)
Post by: fuzzbuzzuk on November 06, 2010, 09:42:02 AM

No... for example. if i input m03 s1000. it will read the speed at 2500rpm.

Title: Re: spindle speed reads (-)
Post by: angel tech on November 06, 2010, 09:46:47 AM

and the spindle is running at 1000 not 2500

Title: Re: spindle speed reads (-)
Post by: fuzzbuzzuk on November 06, 2010, 09:50:42 AM

yep.. my lathe has a max spinlde speed of 2000rpm so i am quite sure its not doing that speed

Title: Re: spindle speed reads (-)
Post by: angel tech on November 06, 2010, 10:29:48 AM

check the index debounce in port and pins/general config, and set it to 0.

Title: Re: spindle speed reads (-)
Post by: fuzzbuzzuk on November 06, 2010, 12:17:34 PM

yea i have been playing about with that. also the spindle pully ratio. ive set it at 0.7. I got this number from the max spindle speed of 2000rpm and max motor speed of 1400rpm. so 2000/1400= 0.7 am i right in doing it that way? seems to of helped a little bit.

Title: Re: spindle speed reads (-)
Post by: fuzzbuzzuk on November 06, 2010, 11:07:48 PM

i ment 1400/2000=0.7

Title: Re: spindle speed reads (-)
Post by: Greg B on January 18, 2012, 03:40:56 AM

I am having a same sort of problem. I have tried changing the pulley ratios from 1.4 to .75. My motor does 1430 RPM and the lathe spindle does 2100 RPM. if I have anything else but 1 in the pulley set up screen. the spindle speed read out of the screen will not read the correct spindle speed. I am checking this with the rev counter so I know what rev's the spindle is doing. I have tried to correct this with the trim pot on my PWM to 0to10v board but it is always reading low even when I have wound the trim pot right up.
Why does the spindle read out change on the screen when you play around with the pulley ratios?

Cheers