Benefits of Clearpath servos?

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DocsMachine
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Benefits of Clearpath servos?

Post by DocsMachine »

Just for mostly-idle conversation, what benefit would I get from switching to Clearpath servos?

My application is a converted Logan lathe (still very much in progress) with the eventual aim of some short run bulk parts production (20 to 100 part runs.) I'm considering this conversion as merely kind of a "stepping stone" to a purpose-built machine, probably the Tormach slant-bed.

From a first glance, the servos are stronger, quieter, faster and are apparently closed loop.

In order, as near as I can tell, my current steppers are plenty powerful for my application (virtually all aluminum parts, sub-1", and on a lathe with a limited maximum spindle speed) and they seemed quiet enough when running (sure, they go "Zweet! Zweet!" but do so fairly quietly, and it's nice to be able to hear the thing moving when you're not watching it directly.)

Faster might be an issue, although I'm still way too green at this to be expecting true industrial-level cycle times, or to trust myself with near-full-speed rapids. :D

The closed-loop part seems to be the one big one, although as I understand it, it's only "closed" with it's own built-in driver. IE, it doesn't communicate back to the controller, which, in my limited understanding of these things, is fairly normal? So again, if the current steppers are sufficiently powerful they don't tend to skip steps, and the feeds & speeds are kept reasonable enough to not overtax the system, where's the real benefit?

And, it seems, enough of a benefit to justify some $500-$600 in new motors?

Doc.
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Re: Benefits of Clearpath servos?

Post by martyscncgarage »

Hi Doc,
Closed loop control is the biggest plus.
Very easily tuned and setup with their software. They can also be detuned in the software to limit torque. Watch their videos

Compact, the servo amplifier is built on the back of the servo motor itself.
You can derate the Clearpath SDSK by 20% (maybe a little more) from the machines original stepper specs. Say the stepper requirement is 200 oz/in. You could get by with a 160 oz/in Clear path SDSK. Check out their YouTube channel Teknic Inc

I have them on a Dyna DM3000 lathe that a friend and I started, just need to finish it up....after the new year hopefully.

Closed loop steppers are another option like this one:
https://www.automationtechnologiesinc.c ... -kl-5080h/
I hope to try these on my next Dyna DM2400 build next year.....




Marty
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Re: Benefits of Clearpath servos?

Post by Dave_C »

All,

I am using these closed loop steppers mentioned in the above post AKA "Hybrid Servos" and they are quite nice. I have the 1200 Oz In version on a G4003G conversion (12X36 Lathe) and they are smooth as silk and never miss a step. Right now you can buy them for $250 each! I paid the $500 each when they first came out but it was still worth the price. They are closed loop just like the clearpath, with encoders on the back of the motors.

They only drawback is you need a large power supply that is quite heavy. Mine weighs in at about 30 lbs but it is a toriod type with dual outputs at 10 amps each. Each motor can pull 6.5 amps!

I have them set for 2,000 steps per turn and 1:1 ratio on with the screws.

I like clearpath as well but I just can't see the justification to spend the extra bucks. Unless you need motor speed, then clearpath may make sense. I can't complain though, I have my setup running at 150 ipm and it will go much faster if I dial it up. No point, I can break things fast enough at 150 IPM!

My 2 cents worth,

Dave C.
Grizzly G0678 Mill ,CNC conversion with Acorn. G4004G Lathe, Mach 3 conversion to Acorn.
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Re: Benefits of Clearpath servos?

Post by frijoli »

Personally I think the DMM servo option is a better choice than the Clearpath.
My reasoning is that they are AC driven and have all the same benefits of the closed loop system without the big Power supply.
One real advantage besides the power supply is that if the motor or drive has a problem you can troubleshoot and replace it. You can't do that with an integral drive/motor.
They have larger motor options as well.
I was going to use Clearpath, but decided I will go DMM instead.

Clay

PS. For Clarity I just started my conversion and haven't installed either as I'm still bench testing and doing mechanical mods.
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Re: Benefits of Clearpath servos?

Post by Reedfirst »

I'd have to agree... I was debating clearpath and DMM and went with DMM as I prefer having seperate drive and motors. Makes troubleshooting easy if somethings isn't right. Testing mine on 120volt power I can squeeze 330ipm out of my bridgeport.

Also DMM servos come with 16bit [65,536ppr] encoders.
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Re: Benefits of Clearpath servos?

Post by ScotY »

I have Clearpath motors and if I hadn't spent so much on their cables I might have returned them and gone for the DMM servos instead. I'm not unhappy with the Clearpath product, in fact they are very nice, but the DMM stuff is the same or a little less with better specs. Also, the AC power setup is nice as well...does away with either a bulky or expensive DC power supply.
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Re: Benefits of Clearpath servos?

Post by martyscncgarage »

ScotY wrote: Tue Nov 21, 2017 12:22 am I have Clearpath motors and if I hadn't spent so much on their cables I might have returned them and gone for the DMM servos instead. I'm not unhappy with the Clearpath product, in fact they are very nice, but the DMM stuff is the same or a little less with better specs. Also, the AC power setup is nice as well...does away with either a bulky or expensive DC power supply.
The DYN2 drive use a DC power supply...The DYN4 drives do not
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Re: Benefits of Clearpath servos?

Post by ScotY »

I was just looking at that...bummer. I guess I'm sticking with the Clearpath stuff for now.
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Re: Benefits of Clearpath servos?

Post by frijoli »

Good catch on the power supply. I will be looking at the Dyn4 drives. It may or may not cost more than the Clearpath.
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Re: Benefits of Clearpath servos?

Post by ScotY »

I emailed DMM today. They are very responsive and helpful. I learned that the Dyn4 can run off 220v or 110v. The catch is in 110v, the max motor rpm is reduced. This may or not matter, depending on your setup.
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