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Author Topic: Does Smoothstepper smooth acceleration?  (Read 18110 times)

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Does Smoothstepper smooth acceleration?
« on: January 12, 2009, 04:53:06 PM »
Does Smoothstepper smooth the acceleration like Quantum does to eliminate the jerks? I got the impression that it did in the Quantum forum when someone said Quantum is no longer necessary now that Smoothstepper is available.


« Last Edit: January 12, 2009, 04:55:08 PM by tahustvedt »

Offline Hood

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Re: Does Smoothstepper smooth acceleration?
« Reply #1 on: January 12, 2009, 05:27:05 PM »
No, its just the same as PP (just cleaner and faster), well as far as I know anyway

Hood

Offline RICH

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Re: Does Smoothstepper smooth acceleration?
« Reply #2 on: January 12, 2009, 05:50:01 PM »
Someone please correct me if what i say is wrong. Thought that in Quantum, the acceleration curve was not linear
like you currently seen in the motor tuning graph. So in quantum, you would have a more gradual approach on decel and accel towards a velocity. In that case even without the Smooth Stepper the machine would be smoother running. Probably more so at higher speeds. A pulse is a pulse,  and if they can be delivered better, as Hood said, you can run faster without missed steps. With in reason.
RICH


Offline Hood

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Re: Does Smoothstepper smooth acceleration?
« Reply #3 on: January 12, 2009, 05:58:37 PM »
Quantum uses S Curve acceleration, not sure whether you can use the SS with quantum.
Hood
Re: Does Smoothstepper smooth acceleration?
« Reply #4 on: January 13, 2009, 02:02:40 PM »
Ok. I'm using Mach3, BTW. So it will actually let me run faster than what I can achieve with just Mach3 and a direct LPT interface?

Sorry if I'm asking stupid questions, I didn't know what it does other than what's explained about the function in the SS manual, which didn't make sense when I read the comment in the Quantum forum. :)

Offline ger21

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Re: Does Smoothstepper smooth acceleration?
« Reply #5 on: January 13, 2009, 05:31:21 PM »
The smoother pulses may make your motors run smoother, which may make them go faster, but unless Mach's kernel speed is limiting your speed, the Smoothstepper doesn't do anything that would give you more speed.
Gerry

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Offline Hood

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Re: Does Smoothstepper smooth acceleration?
« Reply #6 on: January 13, 2009, 06:02:54 PM »
The benefits of the SS are as has been mentioned the smoother pulse which may allow faster speeds from steppers but no guarantee there as it would depend on how nice a pulse your PP was putting out.
It can pulse up to 4MHz compared to the PP max of 100KHz (more likely 45KHz) As Ger said if the pulse rate from  the PP would limit your potential speed then the SS is a good move. A situation where that would be true is if like my lathe the servos have 2000 count encoders (8000 pulses per rev) , with the PP you would be looking at 1.687m/min max (45KHz kernel 5mm pitch screw 1:1 gearing) with the SS the max would be 150m/min. Obviously the motors top speed would be the limiting factor here and I dont  get anywhere near the SS potential ;)
 Another benefit is the pulseing is taken away from the computer so that frees up CPU and also the issues with on board graphics and laptops (although not a 100% guarantee, it seems to be the case)
 The bad points about the SS are it costs $150 , not a huge amount, but if you  cant benefit from any of the above its probably not worth it.
Hood
« Last Edit: January 13, 2009, 06:04:55 PM by Hood »

Offline RICH

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Re: Does Smoothstepper smooth acceleration?
« Reply #7 on: January 13, 2009, 06:07:04 PM »
tahustvedt,
Can only tell what i have experienced from testing and using the SS as compared to running off the PP.
This posting is from my experience only for my equipment, can't speak for anyone else, shouldn't be taken as
endorcing a product, and shouldn't be used to confince you of anything.
Using the SS i can run my machines at a higher velocity. It solved the problem of a poor pulse signal out of the PP which was due to on-board graphics. If you want speed, then have your system favor it or compromise speed to torque as you wish to accompliish what you want to do. As far as speed, the rapid increase was at least 2x
and up to around 4x with out skipping. Now i could get more speed if i bumped the voltage up and get more torque if the current settings were higher, thus POWER can be had in other ways. Big woop! I don't care to tear up my machine to impress anyone!

RICH  
Re: Does Smoothstepper smooth acceleration?
« Reply #8 on: January 14, 2009, 11:55:19 AM »
Ok, thanks.

Re: Does Smoothstepper smooth acceleration?
« Reply #9 on: July 01, 2009, 07:39:35 PM »
I'm not looking for more speed, but my machine seems to have unnecessary vibration.  Can I assume that smooth stepper can help?