VFD and AC Motor replacement project

[allenj20]

Hey Mike
Check it out BALDOR DC Brushless Adjustable Speed: BMC-Series

Also Brushless DC motor, Brushless motor controller, motor driver, stepper motor, DC pump, Brushless water pump, DC Cooling Fan, Mini CNC machine, Plastic mould, aluminum mould, tooling, damper actuator

And

Brushless DC motors with AC drive, Brushless motor

And

http://www.homemachineshop.co.nz/

Personally my choice would be Baldor but no word on the price. The second is a Chinese supplier I would skip that one.

The last two are a Taiwanese option which might be ok the last one is a guy in NZ that is a reseller for the Adlee drive.

[allenj20]

Couple more things.

One Baldor does not mention using the BLDC for a machine tool spindle which may mean it's a misapplication of the technology. It may not be well suited to the task.

Here is a couple of videos of from the reseller of the Adlee

http://www.youtube.com/watch?v=-HJZoEQ6Kok&feature=mfu_in_order&list=UL]Adlee Powertronic AM370-H BLDC Tapping Video - YouTube

and

http://www.youtube.com/watch?v=FoChkN0ga8U&feature=mfu_in_order&list=UL]Adlee Powertronic AM370-H BLDC Testing Video - YouTube

One thing I would want to see is a .500 drilling operation in steel and some steel milling especially plunge or helical operations.

[Al_The_Man]

The Baldor looks like an interesting candidate, one of my material suppliers is a Baldor rep, I will find out more from him.
The spec mentions it can be used in constant torque mode, as well as variable torque.
Al.

[allenj20]

I was thinking more about this.

One thing I am having a hard time reconciling in my mind is. If BLDC tech is so good why do ours perform so poorly? I mean when I compare my Mikni spindle to my Bport clone spindle it is simply ridiculous how badly the Mikni compares.

I might make a video to demonstrate what I am talking about. When I use the recommended feeds and speeds with my Bport clone it cuts like butter. When I try that with my Mikini it's broken endmills and stalled spindles. There really is no comparison.

So I am thinking let's assume it is a real 3HP brushless DC motor. What about the controller could cause what we are seeing in the real world. Then it dawned on me it's in variable torque mode. That would explain what we are seeing. Many drives VFD and otherwise have two modes CT and VT constant torque and variable torque respectively. If this drive is VT only or in VT mode then that would totally explain the real world performance we see.

So it could be as easy as just replacing the drive with something like the Baldor drive in CT mode. That being said I still think integrating it with the Mikini electronics is not the way to go. Simply because I have found the Mikini main board to be flaky. I have seen the LCD flicker fade in and out you tap on it and it comes back. I have seen the steppers take off and keep going without input, spindle halts at no load etc... I also suspect the axis motion problems Swath mentions are probably the Mikini electronics I have seensome of the same stuff.

I find the Mikini electronics to not be worth keeping. I also think integrating with something with a wiring digram and spec sheet like the CNC4PC bobs will be a ton easier. Also for my uses I don't use the manual mode. If I am going to do some ad-hoc operations I use the NFS wizards in Mach3 which are awesome. I personally would much rather have the pendant in Mach3 rather than in a manual mode I never use. I would use it a lot more. So that is my focus.

I think someone should tackle the BLDC drive project as I think it would be interesting. Me I need a solution I KNOW will work. I need a machine tool for my hobbies more than I need a machine tool hobby.

Anyway that's my thoughts

[mcphill]

Good points all around. What's so sad is that if it is in VT mode, then the speed control should be AWESOME. Well, mine drops from 800 to 500 rpm all the time, and takes 3-4 seconds to recover. That is CRAP performance. I think the spindle controller board is a home brew piece of crap not worthy of the mechanical ability of the rest of the machine. It seems much of the rest of the electronics are of the same quality...

I actually would prefer to have an MPG that KEPT it's position in MACH rather than the manual mode we have on the Mikini... I just hate to have that area on the machine where the display and torque meter, etc. are on the face of the Mikini that would display nothing! Then again, I could mount an MPG there, and a few buttons, etc. making it look like it is "supposed" to be there... Or open it up some and put a monitor in there? Or a small keyboard? Touchpad, holes for tools, ...

Hmmm...

BTW, while you are in there, why not swap out the stepper drivers to the new Tormach style too. I doubt the Mikini drivers are anything to write home about. I asked Phil for manuals for them so I could play with different microstepping settings, etc., but he wouldn't share : ( He was concerned I would mess something up. Guess he thinks he's the only one allowed to do that?

[mcphill]

Looks interesting, but specifically states it uses the Hall sensors. The Parker drive doesn't need them. I really like everything I have read on Vector Drives. If the Parker doesn't work out I will look at the Baldor, though - certainly a worthy backup option. Thanks!

[Al_The_Man]

What's so sad is that if it is in VT mode, then the speed control should be AWESOME. Well, mine drops from 800 to 500 rpm all the time, and takes 3-4 seconds to recover.

There is something wrong there, no way that should happen especially in a BLDC motor/drive that has feedback, and what is essentially a synchronous motor.
Al.

[allenj20]

This is the stepper driver on my machine

TAIWAN HOW-MAU CNC MACHINERY, Mini Milling Machine, Desktop Lathe, -- Stepper Motor Driver(4.3A)

It is an RTCL 2 phase stepper driver model number PD2064MA002

I also attached a doc file for it there is probably more info on the net somewhere.

It's really stupid that Phil won't share this info as there is nothing proprietary about it. It is a standard off the shelf Chinese stepper motor driver.

[allenj20]

Also I am thinking once I get the system up and running under Mach control with the CNC4PC BOB I will work on making a custom front control panel as well

[mcphill]

This is the stepper driver on my machine

TAIWAN HOW-MAU CNC MACHINERY, Mini Milling Machine, Desktop Lathe, -- Stepper Motor Driver(4.3A)

It is an RTCL 2 phase stepper driver model number PD2064MA002

I also attached a doc file for it there is probably more info on the net somewhere.

It's really stupid that Phil won't share this info as there is nothing proprietary about it. It is a standard off the shelf Chinese stepper motor driver.

Thanks!

I agree with the lack of documentation. I don't understand the need to "keep it close to the vest". It's not like he would be liable if I killed myself, but that seems to be what he thinks... Of course, a jury is likely to rule either way as well...

[allenj20]

Here's a quick video update got the VFD and motor dialed in.

http://www.youtube.com/watch?v=mfJyOT5Ipn4]Mikini 1610L AC Motor and VFD replacement project video 1 - YouTube

[SWATH]

That's awesome Allen, I would love to see video demonstrating the performance difference when cutting between the BLDC and your new one, especially on the RPM range.