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Author Topic: Servos vs Hybrid Steppers with CS labs controller  (Read 3174 times)

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Servos vs Hybrid Steppers with CS labs controller
« on: October 03, 2017, 01:48:37 PM »
Hi All

Looking for some advice regarding keeping original servos and doing a total upgrade and using Leadshine servo steppers. I have a Denford Senior which has a fanuc ot control. A fault occurred about a year ago but never got to the bottom of it. Decided to do something with it now. Don't really want to throw money at such an old control system.

Considering two options : Option 1 keep the original Sem Mt30 Servos along with the Norwin 2110 drives and use a CS Labs CSMIO/IP-A capable of 0 to 10v for the drives.
                                     Option 2 Try and sell the servos and drives and use appropriate Leadshine Servo stepper motors along with a CS labs CSMIO/IP-M.

Seen some good reviews on the forum about Cs Labs products and would really appreciate any comments.

Many Thanks
Mick


        
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #1 on: October 03, 2017, 02:07:03 PM »
Hi,
the hybrid 'servo steppers' are just stepper motors with a smart drive, useful to be sure but its still a stepper with the same limitations of speed
and torque. The premium you pay for the smart drive gets you too little....either get plain steppers and drives but the next size up OR get proper
AC servos and drives and be done with it.

You pay a premium for analogue capable controllers, if you instead stuck with a cheaper step/dir controller you have more budget for a servo
and drive.

Bang for your buck, ordinary 34 or 42 size low inductance steppers with 80V drives are still easily the most cost effective for hobbyists, if
you need more performance the AC servos are the answer...no in between nonsense.

Craig
My wife left with my best friend...
     and I miss him!
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #2 on: October 03, 2017, 03:06:17 PM »
Hi Craig

Thanks for your reply. Haven't really looked at going out and buying new servo motors and drivers due to cost. Was trying to utilize the original servos if it was a better option. Did think that using the servo steppers would cure loosing steps. Did a conversion a few years ago and never got it right. Very limited speed and threading was never very good.
What would you recommend on a cheaper step and direction controller?

Cheers
Mick
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #3 on: October 03, 2017, 04:05:04 PM »
Hi,
the 80V capable Geckos, Gecko have a great rep but reasonably pricey

ger21, very experinenced CNCer, says:
Quote
Get some Leadshine AM882's from Ebay, and some low inductance, high current steppers, and you'll get all the speed  and power you need. And they'll run smoother, cooler and quieter than what you have.

Craig
My wife left with my best friend...
     and I miss him!
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #4 on: October 03, 2017, 04:54:07 PM »
Hi,
sorry misread your post, I guessed you were talking about stepper drivers.

I personally use, like and recommend an Ethernet Smoothstepper from Warp9. As it turns out there are a few choices.
Don't buy Chinese, most of its rubbish and little or no help when you get stuck.

Beware also the there are some Chinese knock-offs on Ebay trying to pass as a UC100...don't go there!

Craig
My wife left with my best friend...
     and I miss him!
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #5 on: October 04, 2017, 07:10:14 AM »
Hi Craig

Will look into those control boards. Thanks for your time.

Cheers
Mick
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #6 on: October 04, 2017, 10:10:01 AM »
Hi,
I can find some documentation about the SEM30 and Norwin drives, but doubt the models I've seen are indentical to yours but none the
less can well imagine that you wish to retain them if they are in working order. That would require an analogue output controller.
As you say CSLabs do a nice unit but around $600 and Vital Systems also have a good reputation but their analogue ready controller is $1200.
Galill is really classy gear but three axis analogue around $2000.
An ESS by Warp9 (step/dir) is $180. The difference between the CsLabs analogue and the ESS is about $400, still not enuf to replace the servos
certainly with AC servos but you may find that good sized steppers and drives can be had for that budget.

My concern would be 'what happens if one of the Norwin drives craps out?' Can I repair it? Could it be replaced and how much? So there is a risk
in retaining the old servos and drives over and above the premium paid for an analogue controller.

Price two 34 size low inductance steppers, big suckers, 800 oz.in or better, 72V supply and two AM882s. When set up properly they should not lose steps
and will be quick if not as fast as the servos they replace. You may like the idea that the smart drives can overcome lost steps but if you are pushing steppers
to the extent that they start losing steps then its probable that the drives will throw a 'following fault' error. Don't be taken in by the advertising hype.

Craig
My wife left with my best friend...
     and I miss him!
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #7 on: October 04, 2017, 01:17:52 PM »
Hi Craig

Norwin are still repairing the drives as I had one repaired a year or so ago. Only cost about £100 (May have been lucky). I think it would be nice to use the servo's and existing drives but after further thought it really makes no sense. At some point in the future maybe not this year someone will need those servo's and drives to fix a machine and probably pay decent money. So I think replacement with steppers is the way I will go.

If I was to go for ordinary steppers without encoders is there any particular brand you would recommend? There loads available all over the net but what do you buy?
I looked at the Smooth stepper and found a company in the Uk that has them. Obviously that still needs a breakout board so need to take that into account and what to use? The Cs Labs  CSMIO/IP-M 4  is around £270 and doesn't require BOB.

Really want to get this one right. The last conversion was poor to say the least.

Cheers
Mick


Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #8 on: October 04, 2017, 01:49:35 PM »
Hi,
Quote
The Cs Labs  CSMIO/IP-M 4  is around £270 and doesn't require BOB.
Check out the restricted functionality, it doesn't look quite as appealing.

Plain two phase steppers are as you say very common. I have no recomndation to make that favours one manufacturer over another.
Not all manufacturers list the inductance but is an important figure of merit, go for the least in a given size. 800+ oz.in 34 size are likely
to be 6+A try to find units with inductance less than 5mH.

Craig
My wife left with my best friend...
     and I miss him!
Re: Servos vs Hybrid Steppers with CS labs controller
« Reply #9 on: October 05, 2017, 12:22:36 AM »
Hi Craig

Thanks for the info. Will do some more research.

Cheers
Mick