[Starleper1]

I don't have a specific wiring diagram but here's generally how all VFD's work with a 0-10v external speed reference.

You would hook up your C32 0-10v output to the analog input on the VFD (Circled in red). Then you just need to set the parameter within the drive to take it's speed reference from a 0-10v analog signal. That's all that's to it really. Pretty much everything else is done within Mach3 to setup the spindle.

Note that diagram was taken from the GS3 drive manual, sold by automationdirect.com

[Mad Welder]

Cheers again :cheers:and you are bang on I can use my existing C32 BOBCNC4PC
I'm looking at around a 1.5 to 2HP three phase AC motor and the DURApulse Sencorless AC Drive to suit The best way to buy industrial controls--low prices, fast shipping and superior service..

I came across another link here too for anyone else like myself learning about Sensorless vector control variable frequency drive (VFD) How does Sensorless vector control VFD work?: AC Drive

as you said it's not a cheap move either but from what I've been reading and what I've been told from some suppliers here at home the actual electricity/utility cost in running a three phase motor could actually pay for the product over time (depending on hours running of course) as compared to a single phase DC motor the power consumption of a three phase AC motor is minimal.....and I didn't know that either...

[Starleper1]

Sounds about right. I went with a 2hp motor. One nice thing about AC motors, is they come in standard frame sizes. For instance, any 56 frame motor will fit any 56 mount, weather it be face, or base mount. This makes it easy to swap out motors when necessary.

[Mad Welder]

yeah the 56 chasis was what I was looking at the dimensions look relatively ok 6" diameter and 12" long or in our case high.....and the three phase motor allows up to 3800RPM as opposed to 1800 with the single phase motor. and with a 1:2 ration that allows a max of 7600RPM if the job dictated that requirement, and the three phase motor is even lighter too less weight on the Z axis.

:cheers:

[Starleper1]

yeah the 56 chasis was what I was looking at the dimensions look relatively ok 6" diameter and 12" long or in our case high.....and the three phase motor allows up to 3800RPM as opposed to 1800 with the single phase motor. and with a 1:2 ration that allows a max of 7600RPM if the job dictated that requirement, and the three phase motor is even lighter too less weight on the Z axis.

:cheers:

The number of phases doesn't reflect RPM. The number of poles inside the motor do though. 4pole=1800 2pole=3600. But the 4pole has twice as much torque as the 2pole. You never get something for nothing.

[Bob La Londe]

and for those of you who never worked on brass beware the dam stuff sprays tiny sharp needles EVERYWHERE ha my fingers were like small cactus

Brass, and cheap chinese "iron" castings.

[Mad Welder]

The number of phases doesn't reflect RPM. The number of poles inside the motor do though. 4pole=1800 2pole=3600. But the 4pole has twice as much torque as the 2pole. You never get something for nothing.

Cheers again:cheers: I wasn’t aware of that and if my understanding is correct here…. hypothetically I could make a belt drive pulley to fit the motor and suggesting here the pulley diameter of 1.5” and then make a spindle receiving pulley with a diameter of 3” I would double the motor RPM at the spindle without decreasing/affecting torque yeah, but if I bought a two pole I would have half the torque regardless of the RPM??

[Bob La Londe]

Cheers again:cheers: I wasn’t aware of that and if my understanding is correct here…. hypothetically I could make a belt drive pulley to fit the motor and suggesting here the pulley diameter of 1.5” and then make a spindle receiving pulley with a diameter of 3” I would double the motor RPM at the spindle without decreasing/affecting torque yeah, but if I bought a two pole I would have half the torque regardless of the RPM??

No. Torque at the spindle would be decreased. That's ok though. Faster speeds are for lighter cuts. Hence why you spin a small drill bit a lot faster than a giant one. As the other poster said, its always a trade off. The only way to get more torque and more RPM at the spindle is to go with a bigger motor.

[Mad Welder]

No. Torque at the spindle would be decreased. That's ok though..........

as I'm a newbie don't go all technical but in simplest terms why?

Brass, and cheap chinese "iron" castings.

the brass was from my own stock as that's all I had available to machine ballnut mounts at the time

[Bob La Londe]

It takes more energy to run faster right? You can either go fast or carry a heavy load, but not both unless you also get stronger.

The average person can sprint pretty fast right. Can they sprint as fast carrying a 100 pound pack? A 200 pound pack?

Is that un technical enough?

[Starleper1]

The easiest way to explain it, is mathematically. The formula for torque is HP x 5252/RPM

So for instance lets say you use a 2hp motor and through your pulleys you get a max speed of 5000RPM. Horsepower stays the same regardless of speed. If we run it through the formula as follows. Torque = 2 * 5252/5000 you end up with 2.1 lb/ft

Now take the same parameters but reduce your max speed to 2500RPM. Torque = 2 * 5252/2500 you end up with 4.2 lb/ft. So as you can see the outcome is linear.

Hope this helps.

[Bob La Londe]

There is a freak though. Stepper motors are always powered at full power. They move by fighting themselves. (actually many controllers reduce power when not receiving step direction signals and the motor is stationary) The net result is that they have better torque figures at the motor shaft with lower RPM so often it works out that using a pulley to increase speed rather than running the stepper at higher speed gives more torque at the screw, spindle, etc driven by the stepper.

I had to throw that in there just to muddy things up of course. LOL.

[Starleper1]

The formula I explained is generally used for induction motors. Steppers are irrelevant here. But your right steppers are a different beast.

[ihavenofish]

There is a freak though. Stepper motors are always powered at full power. They move by fighting themselves. (actually many controllers reduce power when not receiving step direction signals and the motor is stationary) The net result is that they have better torque figures at the motor shaft with lower RPM so often it works out that using a pulley to increase speed rather than running the stepper at higher speed gives more torque at the screw, spindle, etc driven by the stepper.

I had to throw that in there just to muddy things up of course. LOL.

steppers are always under full torque yes, but not power.
1NM torque at 0 rpm is still 0 output power.

the same is true for the induction motors. steppers are commanded differently, but they cant be changing the laws of physics

[Bob La Londe]

:bat::bat::bat:

steppers are always under full torque yes, but not power.
1NM torque at 0 rpm is still 0 output power.

the same is true for the induction motors. steppers are commanded differently, but they cant be changing the laws of physics

[jdurkin]

It takes more energy to run faster right? You can either go fast or carry a heavy load, but not both unless you also get stronger.

The average person run sprint pretty fast right. Can they sprint as fast carrying a 100 pound pack? A 200 pound pack?

Is that un technical enough?

kid gloves on newbie Mad Welder there Bob Director

"Hope this helps" is much nicer

Good input though!

[Mad Welder]

Wow interesting turn of events…..

The average person run sprint pretty fast right. Can they sprint as fast carrying a 100 pound pack? A 200 pound pack?

Is that un technical enough?

Yup I can understand that cheers

The easiest way to explain it, is mathematically…………Hope this helps.

Cheers again Starleper1 am I correct here in understanding that as you reduce RPM you increase Torque respectively?

steppers are always under full torque yes, but not power.
1NM torque at 0 rpm is still 0 output power.

the same is true for the induction motors. steppers are commanded differently, but they cant be changing the laws of physics

Bob La Londe not sure why the ‘Bats’ image was displayed here with ihavenofish’s post but if there’s something problematic going on here outside of my thread….1>don’t bring it in here as I'm not interested and don’t wan’t to know either and 2> if I’ve misunderstood the ‘bats’ image intentions then cheers for the input lads

kid gloves on newbie Mad Welder there Bob Director

"Hope this helps" is much nicer

Good input though!

Aw shucks some one is looking out for me

[Bob La Londe]

Bob La Londe not sure why the ‘Bats’ image was displayed here with ihavenofish’s post but if there’s something problematic going on here outside of my thread….1>don’t bring it in here as I'm not interested and don’t wan’t to know either and 2> if I’ve misunderstood the ‘bats’ image intentions then cheers for the input lads

Look at the smiley before it grows wings. Then say "Doh!" I didn't realize it kept going when I first put it in. Just saw it went from plane to red faced. Actually, my point was valid even if technically its providing no motive power when stationary.

You asked for a non-technical answer and that was the least technical answer I could think of.

Sorry, for trying to help. I'll try to remember not to do that again.

[aarggh]

Sorry, for trying to help. I'll try to remember not to do that again.

Bob,

The trying to help wasn't the issue, the issue brought up, (and I apologise if I am reading it wrong), was the condescending and insulting way you responded. The guy's clearly asking for the benefit of more experienced people, not to be insulted and belittled in a public forum. I see a lot on this forum very often unfortunately that some of the more experienced people seem to forget that everyone has to start somewhere, and that start is usually by asking questions, and no matter how silly they might seem to experienced people, to the newbie they are the starting point of their reference view.

Less attitude and more genuine help would go along way in these forums with a lot of people here.

cheers,
Ian

[Bob La Londe]

Bob,

The trying to help wasn't the issue, the issue brought up, (and I apologise if I am reading it wrong), was the condescending and insulting way you responded. The guy's clearly asking for the benefit of more experienced people, not to be insulted and belittled in a public forum. I see a lot on this forum very often unfortunately that some of the more experienced people seem to forget that everyone has to start somewhere, and that start is usually by asking questions, and no matter how silly they might seem to experienced people, to the newbie they are the starting point of their reference view.

Less attitude and more genuine help would go along way in these forums with a lot of people here.

cheers,
Ian

Actually I was not responding to you, hence why I didn't quote you. I specifically quoted the person I was responding to. That's one of the things quotes are for. Had nothing to do with your attitude or your perceptions. I accepted your original problem for what it was and moved on.

So you don't like my attitude or atleast the way you perceived my attitude. That's really your problem. Not mine.

I gave the OP exactly what they asked for. A simple not technical explanation by way of analogy. Like I said. I won't make that mistake again. (I tutored a number of subjects in college and exactly that approach was quite successful. I had a number of professors ask if I minded if they used some of my analogies in ther classes.) I also did something I have learned in a couple decades of business. I asked the subject if they understood. All the clever (or not so clever) analogies are useless if you don't verify that it worked.

I may offer somebody else my "attitude" and opinion or explanation, but this poster will not benefit (or be harmed) by my opinion again, not because you had a problem with your personal perception, but because of their own projection of a nonexistant outside problematic relationship of some kind.

I personally think some of the "more experienced" people here don't hear what people actually ask sometimes. Their experience cloggs up their ears.

Cheers? Really?

While not quite at the same level I always found that analogous to the little kid who thinks its ok to expel vitriole at the expense of others if they say, "Just kidding!" at the end of it.

I am now going to quit following this thread. Obviously I am not welcome here. I wish it didn't still come up in "my replies" though. Can't have everything I guess. LOL. Best of luck to the OP. (sincerely)