Easy Servo Drive?

[Tenson]

Can anyone tell me the difference between the Leadshine easy servo drives on the current Leadshine website (ES-M22430 motor with ES-D808 drive) and the similar spec Leadshine combo I see on eBay (60HS30-EC-1000 motor with HBS86 drive)?

Leadshine website - http://www.leadshine.com/productdeta...odel=ES-M22430

eBay - http://www.ebay.com/itm/Leadshine-3N.../191633860794?

[Dragonfly]

I think hey are the same and are not real servo drives as such. It's a stepper motor with closed loop control. Servo motors are usually 3 phase AC driven, or brushed DC motors.

[Tenson]

Any idea why the numbers for the parts are different?

In terms of electronics a servo is just a closed loop system, i.e. it has negative feedback, so whether the motors are steppers, DC or AC, brushed or brushless the servo is the feedback component of the system.

[JAZZCNC]

Any idea why the numbers for the parts are different?

Yes the HBS are the early version of the drive and superceded by the ES-D. Pretty much the same drive just with updated software.

It's a like the EM806 superceded the AM882 which are basicly same electronics with updated software. Slight improvement in smoothness with the EM compared to AM but nothing to get excited about or a pay lot extra for.
Similiar with the ES-D over the HBS thou I do think there as been lot more tweaks and some performance gains compared to the AM/EM range.

The Easy Servo works exactly like a Servo system it just use's a stepper motor so can't spin has fast or has the linear torque like servo motor offers.
In terms of accurecy then servo's resolution is usually higher with higher count encoders but at this lower level with lower grade ballscrews etc then stepper system if sized and tuned correctly will give them a good close run chase on accurecy.!

Now let me just say this which may make you look again at why you want this closed loop or any Servo system for that matter.?

Closed loop just means it will closely follow the path it's be told to follow and if outside of it's set parameters it will fault.
If it strays from the path slightly the electronics will bring it back on path.! . .. BUT the fact still remains it's lost it's way along the path and the damage is done. It's cutaway material that can't be put back.?
Yes when it finishes the Job it won't have lost it's starting position and will go back to exactly the same place. BUT still the fact remains it strayed and cut material it shouldn't have so job is wrong.!

Like saying that's nice straight edge but whats this squigly bit then goes straight again .? Oh the servo got lost for fraction of second but it's ok it remembered where it was and carried on ok.!!! . . . . No the thing is still fubar because it shouldn't have squigle in it.!

Steppers if sized and tuned correctly are perfectly fine. For larger machines or machines that need rapid movement then servos rule but at lower level then steppers are not far behind servos and IME servos offer nothing other than extra power and slightly smoother if tuned correctly. The Closed loop means nothing really, lost is still lost be that a little or lot still means the job is wrong.

[GEOFFREY]

Surely one advantage with closed loop is that if the following error is set to a very small figure, the machine will just stop, and not perform any squiggles, rather than continue after a machining error? G.

[JAZZCNC]

Surely one advantage with closed loop is that if the following error is set to a very small figure, the machine will just stop, and not perform any squiggles, rather than continue after a machining error? G.

Yes geoffrey that is true upto a point and actually how servos work. Lots people don't realise that a servo never actually is truely on the path but instead is continually off course and making tiny tiny course adjustments TRYING to get back on the path. Obviously these adjustments are so small they are not seen in normal use.
But if you set the parameters too high then you will be open to faults all the time. It's essentially a balance between accurecy and reliabilty.
Also it only faults AFTER it's got lost so still some damage is done, yes with high falling error setting you have limited it but still material you didn't want to lose has gone.!

Now don't get me wrong I'm not saying Servo's are Rubbish or not better than Steppers because they are in several ways. BUT not always in the ways people think and they certainly often put too much focus on the closed loop aspect when in real terms it offers very little over a properly Sized and setup stepper system. Esp at DIY level to Low end industrial use.

[Tenson]

I should point out I mostly use 3mm dia. cutters so this means my direction changes need to be more frequent and smaller. Maybe I'll make a video tomorrow and show you.

Gantry weight I dunno but the whole back is a massive slab of Ali. I guess 60kg.

[JAZZCNC]

I should point out I mostly use 3mm dia. cutters so this means my direction changes need to be more frequent and smaller. Maybe I'll make a video tomorrow and show you.

Gantry weight I dunno but the whole back is a massive slab of Ali. I guess 60kg.

I doubt it's heavier than My wide all Ali gantry which is 70Kg and I do everything from fine engraving with tiny cutters to Hogging out lumps of ali and don't have any troubles. To be honest if mechanicly sound then I'd put a small wager on that your problem is overtuned motors and not undersized motors.

Again same would kind of happen with closed loop.? The difference being they would or could depending on how much error fault because would still be loosing position due to being overtuned and following error will be reached.

Also what are you using to provide the pulses.? If parallel port then this could also be some of the problem.
The secret to a sound relaible machine is balance and each component needs to match and work nice together with others in the system. One weak link and the machine will be compromised in some way.!!

[Tenson]

Thanks for your replies.

Yes I am using the parallel port of a Sony Vaio Pentium 4 laptop. One thing I notice is that I get an occasional delay when jogging if the wi-fi is active. So I disable it when running.

Motors are 4nm nema 24. One pair for the main gantry (y axis) is driven from 80V and the x axis and z axis are driven from 50V. I thought the lighter weight would need less voltage but I think I probably made a mistake there as I suspect voltage directly affects motor top speed, while current affects torque? In which case my x axis will not be able to reach such a high RPM as the Y axis even though it has less weight to move.

I made a video just now. I must admit there are no problems with it in this case, lol! But I think it shows my point that the direction changes are fast at the center of the circle. This was at 2000mm/min. Circles do seem less round at higher speed and more round at lower speed. In this project I need to cut some 6mm holes and use a 3mm cutter, so the gantry will need to make very small adjustments and fast if the feedrate is high.

Anyway here it is, be gentle!

https://youtu.be/3mmX7BZWEjQ

[JAZZCNC]

Thanks for your replies.

Yes I am using the parallel port of a Sony Vaio Pentium 4 laptop. One thing I notice is that I get an occasional delay when jogging if the wi-fi is active. So I disable it when running.

Ok well for a start you have rotating ballnuts and twin motors so you shouldn't be having any issues with loosing position due to lack of power.
My Gantry is much heavier than yours and I can cut what you where doing twice has fast you where and still not loose position.

I'm 99% sure your problem is coming from the Laptop and parallel port. For starters Mach3 doesn't suppport Laptop with PP for this very reason of it being unreliable with the pulses coming out of it.

If you where running an external Motion controller you wouldn't be having this problem. To be honest at this speed you probably wouldn't with the PP on a decent PC with good PP. But you certainly won't with External Controller. And you'd still be able to use the Laptop.

I'll lend you a USB Smooth stepper if you want to try one.! . . . . Fry it and you bought it thou.
If your going to buy one then buy Ethernet not USB.