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Author Topic: To smoothstepper or not?  (Read 599 times)

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To smoothstepper or not?
« on: December 07, 2018, 02:07:56 PM »
For any of you that have made the transition to using a smoothstepper in place of the typical dB 25 cable , how much of a difference ,if any, has it made to the performance of your setup? I was having signal loss issues and the mfg the has recommended going with a smoothstepper to help and says the machine will run better and faster  with that addition. Now for most of what I do my machine is plants fast enough but if I can do some jobs quicker that would be a plus . I’d like to hear from someone who has made the switch personally
Re: To smoothstepper or not?
« Reply #1 on: December 07, 2018, 02:30:15 PM »
Hi,
when I went to an Ethernet SmoothStepper, a genuine Warp9 TD unit, not some Chinese knock off.....don't worry there are plenty out there,
I was able up increase my G0 traverse speed by 33% and the motors run a little cooler and sound 'smoother'.

Craig
My wife left with my best friend...
     and I miss him!
Re: To smoothstepper or not?
« Reply #2 on: December 07, 2018, 03:50:37 PM »
Hi,
just as an aside in most circumstances increasing the G0 maximum velocity does not improve cycle times a great deal.
Most CNC jobs do not spend a great deal of time operating at maximum G0 speeds but are accelerating up to that speed
but then have to start slowing down again without ever having reached maximum speed.

Increasing maximum acceleration is very much more relevant to cycle time under those circumstances and acceleration
comes back to motor torque. When I fitted and set up my ESS (Ethernet SmoothStepper) I increased the acceleration in
addition to the max speed. I can't remember by how much. I do remember increasing it (without losing steps) so much that
my machine was rocking around so much that I had to tie it to the wall! So I backed off quite a bit. So my machine is capable
of quite a bit more acceleration than I'm comfortable with in practice. I'm sorry I don't have or recall any numbers or even indeed
whether it was the ESS that allowed the increase, it may be that the machine was capable of considerably higher acceleration
when I was still using the parallel port as well.

Craig
My wife left with my best friend...
     and I miss him!
Re: To smoothstepper or not?
« Reply #3 on: December 07, 2018, 07:34:57 PM »
Did you notice any improvement in the quality of the cuts you were making ? I know with mine  and the bits I’m using I’m limited in the actual speed we can cut at . Currently cutting 1/2” plywood with 1/8 down spiral bits at full depth has given the best results in the shortest times
Re: To smoothstepper or not?
« Reply #4 on: December 07, 2018, 08:39:12 PM »
Hi,

Quote
Did you notice any improvement in the quality of the cuts you were making
No, not really, I mean a parallel port would have to screw up pretty badly before it deviated from the toolpath or jittered
enough to affect the cut quality. Of course the parallel port did from time to tine screw just exactly that badly.

The SmoothStepper is better in that regard....it takes a lot more hamfisted interference by me before it screws up.

I've always commented of the money spent on improving my machine the best value were good quality roller plunger microswitches
for my home switches and the next best item is my ESS.

Craig
My wife left with my best friend...
     and I miss him!

Offline ger21

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Re: To smoothstepper or not?
« Reply #5 on: December 07, 2018, 08:58:55 PM »
Quote
I was having signal loss issues

What do you mean by "signal loss"??
There's really no signal to lose when using the parallel port.

On a machine that runs good with a parallel port, you may not see much improvement at all with an ESS.
If you run Drivertest .exe in the Mach3 folder, do you get a smooth, flat line and a steady pulse rate?
Gerry

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Re: To smoothstepper or not?
« Reply #6 on: December 07, 2018, 09:29:39 PM »
Not so much signal loss , more so electrical noise or interference. We had issue with the z axis basically losing its place and plunging down through the workpiece and stalling the spindle . Needless to say this wasn’t good for the workpiece or the bits.
Re: To smoothstepper or not?
« Reply #7 on: December 07, 2018, 09:34:11 PM »
Hi Gerry,
I always had a pretty good run out of the parallel port and had a very good 'flat line' DriverTest.exe response. As such I did not expect to see
a dramatic improvement when I went to a SmoothStepper.

What I got impressed me, I had been running my 5 phase Vexta steppers at 1800 rpm during G0's without good reliability under the parallel port.
When I switched to the ESS I was able to increase the G0 speed to 2400 rpm and run marginally cooler. Also the sound the motors make it not as harsh.
I ascribed, maybe mistakenly, that the 2-4us of jitter of the parallel port was sufficient to induce a rather harsher noise than the same motor under the ESS.

The only time I got into any bother with the parallel port is if I had some CPU intensive task running in the background or a large file where the redraws would
either stop, stall or stutter Mach. I've found the ESS to be somewhat more forgiving in that regard.

The increased range of highly suitable PC's and OS's that come from using a good external motion controller lead me to recommend such a controller alone.
The perceived, real or otherwise, increase in performance is a bonus.

Craig
My wife left with my best friend...
     and I miss him!

Offline ger21

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Re: To smoothstepper or not?
« Reply #8 on: December 07, 2018, 09:35:25 PM »
It will only eliminate interference if it's the parallel cable that is picking up the interference.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html

Offline ger21

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Re: To smoothstepper or not?
« Reply #9 on: December 07, 2018, 09:37:17 PM »
All I'm saying is that I've read a lot of posts from people that have seen a huge increase in performance, and I've read a lot of posts from people that saw little to no difference.
YMMV. :)
Especially in this case, where it doesn't appear that the parallel port is the problem.
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html