[MornJHC]

First of all I apologize if this post seems a bit out of place here. I am a fresh newbie to the CNCZone forum which is probably quite obvious from my number of posts. While the HUGE number of sub-forums here give me a lot of options it also confuses me tremendously

Anyway, I have been reading some of the build threads here for a couple of days now. Many of the projects look interesting to make me want to try a similar build. However right now due to lack of time I need to have a quick solution for a personal project involving precise movements in 3D. I have been looking around for integrated DC servo motors for this application but most of them are much more expensive than if you do-it-yourself. So the question I have is if and where I can buy a cheap integrated servo motor that:

- operates under 12-24V and ~100W
- provides a maximal torque no less than 140 oz-in
- Preferably able to work continuously at 6000 RPM and maximal torque

Any input is appreciated! Thanks!

[rockcliff]

Cost and Selection of servo components, kind of depends on the type of programming and control your planning on using, for motion

When you say “integrated” do you mean as a complete system electronically ?

[rowbare]

I think you better do some math. 140 oz/in at 6000 rpm is a heck of a lot more than 100 W...

As an example, the BM130 on this page comes pretty close to what you are asking for: BM Brushless Rotary Motors

It is rated ~140 oz/in continuous but at only 4000 rpm. Even at that it is drawing 300+ W. And that is not a cheap motor...

How did you decide upon your motor requirements? As newbies we all grossly over estimate what we need in terms of power, speed and accuracy. Take a look at some of the build threads and conversions and after you read a few dozen or so, you will start to get an idea of what makes sense.

bob

[keebler303]

140 oz-in (not oz/in) at 6000 RPM is 621 watts of mechanical power. Accounting for the inefficiency of the motor, you are looking at around 1000 watts electrical power.

At 24V, that is about 40 amps of current. If you need 3 axes then you need a 120amp power supply. I think you may need to reevaluate your plans.

Here is an industrial AC servo motor that just barely meets the torque and speed criteria: BALDOR AC Brushless Servo Motor Performance Graph: BSM N-Series
List price is $925 without a servo drive or cables.

[MornJHC]

Yes by integrated I mean an all-in-one package including motor, encoder, control circuit, etc. Preferably it should be plug-and-play, whereas I can connect the motor to computer using USB cable (and also hook it up to a 12-24V power supply of course) and just control it using computer software (and avoid PLC control).

[MornJHC]

Thanks for showing the calculation. It is an obvious mistake which I should have avoided in the beginning by actually checking the numbers. Just talked with the engineer and of course the figure I gave above was really ridiculous. What I actually need are:

- operates under 12-24V and ~100W
- provides a maximal torque no less than 210 oz-in
- Top speed at 6000 RPM
- Nominal speed at 3000 RPM
- Nominal torque not less than 45 oz-in

[rockcliff]

Yes by integrated I mean an all-in-one package including motor, encoder, control circuit, etc. Preferably it should be plug-and-play, whereas I can connect the motor to computer using USB cable (and also hook it up to a 12-24V power supply of course) and just control it using computer software (and avoid PLC control).

I would lean more to proven and popular electronics and software for standard motion, possibly consider Gecko's G320x drivers with Mach3 or EMC for pc software control
and hardware for USB, there are plenty of suppliers around that would assemble it into a plug and play type system, it's very common stuff