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### Author Topic: I messed up with my new bench: EMF  (Read 6164 times)

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#### danilom

• 28
##### Re: I messed up with my new bench: EMF
« Reply #10 on: January 26, 2016, 06:37:46 PM »
You should try another PC, this one seems to have bad latency issue or use some motion controller for generating pulses if you need more than 25khz for step lines.

#### Mogal

• 76
##### Re: I messed up with my new bench: EMF
« Reply #11 on: February 14, 2016, 09:55:49 PM »
I have my steppers set at a speed of 140ipm.
The DRO reads out 152ipm when I rapid move.
Any ideas to this one?
Got me completely stumped

#### garyhlucas

• 663
##### Re: I messed up with my new bench: EMF
« Reply #12 on: February 15, 2016, 07:31:52 AM »
Two things, if the rapid is two axis moving at the same time then the combined velocity will be higher than either axis alone. Its a rapid, be happy that it goes as fast as possible when not doing any cutting. As long as position is correct you are good to go.

#### stirling

• 2,188
• UK
##### Re: I messed up with my new bench: EMF
« Reply #13 on: February 15, 2016, 08:47:27 AM »
BUT!

I have my steppers set at a speed of 140ipm.
The DRO reads out 152ipm when I rapid move.

Turns out the frequency is actually 27,300 pulses (Not 25,000)

There's your answer right there in the numbers.

27300 / 25000 = 1.092

1.092 * 140 = 152.88

Unless your PC shows a rock steady exact 25000 pulse frequency (which I'd be surprised if anyone's does) then this is what happens.

Perhaps more curiously, when I FIRST start Mach, the actual pulse frequency is a rock steady 25,324. However if I close and restart, this drops to a rock steady 24,397. If I close and restart again it's rock steady at 23,674. Closing/re-starting from then on has no further effect and it remains at 23,674. If I re-boot then the whole (3) cycle will repeat exactly. Just one of those Mach3 things I suppose.

#### Tweakie.CNC

• 7,945
• Super Kitty
##### Re: I messed up with my new bench: EMF
« Reply #14 on: February 15, 2016, 08:53:15 AM »
Quote
Perhaps more curiously, when I FIRST start Mach, the actual pulse frequency is a rock steady 25,324. However if I close and restart, this drops to a rock steady 24,397. If I close and restart again it's rock steady at 23,674. Closing/re-starting from then on has no further effect and it remains at 23,674. If I re-boot then the whole (3) cycle will repeat exactly. Just one of those Mach3 things I suppose.

How on earth you discovered that beats me - it appears that the more I learn, the less I know about Mach3.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

#### stirling

• 2,188
• UK
##### Re: I messed up with my new bench: EMF
« Reply #15 on: February 15, 2016, 11:15:29 AM »
I'd be very happy to tell you exactly how I discovered it - if only I could remember

#### Mogal

• 76
##### Re: I messed up with my new bench: EMF
« Reply #16 on: February 15, 2016, 03:17:18 PM »
BUT!

I have my steppers set at a speed of 140ipm.
The DRO reads out 152ipm when I rapid move.

Turns out the frequency is actually 27,300 pulses (Not 25,000)

There's your answer right there in the numbers.

27300 / 25000 = 1.092

1.092 * 140 = 152.88

Unless your PC shows a rock steady exact 25000 pulse frequency (which I'd be surprised if anyone's does) then this is what happens.

Perhaps more curiously, when I FIRST start Mach, the actual pulse frequency is a rock steady 25,324. However if I close and restart, this drops to a rock steady 24,397. If I close and restart again it's rock steady at 23,674. Closing/re-starting from then on has no further effect and it remains at 23,674. If I re-boot then the whole (3) cycle will repeat exactly. Just one of those Mach3 things I suppose.

Okay, thanks for verifying that for me...
Know that I "know" its okay I can continue with the next step.

So...

@ 25k pulse, everything 'seems' to be good, but at 35k pulse, I'm losing steps...