[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.

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

[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.

[mcphill]

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.

I've been contemplating how to show the difference when I do mine... I don't want to have to swap back and forth, but I do want to be able to show setup "A" couldn't do X, but setup "B" can...

Any suggestions?

Maybe a 1/2 slot endmill and let it ramp down in to aluminum until it stalls?

[allenj20]

Another quick video update

It's going to be a tight fit.

[ame=http://www.youtube.com/watch?v=0IMFq6Owbas]Mikini 1610L AC Motor and VFD replacement project video 2 - YouTube[/ame]

[mcphill]

Another quick video update

It's going to be a tight fit.

Mikini 1610L AC Motor and VFD replacement project video 2 - YouTube

Would you mind taking some pix/video down in the "hole" where the motor spindle/pulley sits? Curious what it looks like in there...

[SWATH]

I've been contemplating how to show the difference when I do mine... I don't want to have to swap back and forth, but I do want to be able to show setup "A" couldn't do X, but setup "B" can...

Any suggestions?

Maybe a 1/2 slot endmill and let it ramp down in to aluminum until it stalls?

Good question. The ramping is a good idea but you only have so deep you can go. I'm thinking maybe multiple full depth slots at increasing feeds until it stalls, perhaps at low RPM spindle speeds calculated for steel instead of Al.

[allenj20]

Would you mind taking some pix/video down in the "hole" where the motor spindle/pulley sits? Curious what it looks like in there...

Here ya go Mike

[allenj20]

Here is what I have for the motor mount assembly CAD is more or less done just need to do the CAM now.

[mcphill]

Here ya go Mike

Wow, lots of room down in there!

[Al_The_Man]

Anyone have, or know of a BLDC spindle motor off of these machines that would be available for testing and evaluation with various drives, including new design?
Someone replaced with a motor and VFD maybe?
Please PM me with cost if one is available.
Al.

[allenj20]

Al PM sent

Here is another video update

This is from last weekend the motor mount is about done.

http://youtu.be/28grkYwIitY

Work is currently slowing me down a bit.

Should get a chance to work on it more tonight

[allenj20]

My thinking on showing the difference between the BLDC and AC motor is steel milling. That seems to be what the system currently struggles to accomplish due to the lower RPMs called for steel. At 3500-6500 in Aluminium the BLDC does a reasonable job.

[slowtwitch]

Anyone have, or know of a BLDC spindle motor off of these machines that would be available for testing and evaluation with various drives, including new design?
Someone replaced with a motor and VFD maybe?
Please PM me with cost if one is available.
Al.

Al, I have a spare motor, but, I would need to put it back together. It's the motor that Mikini said I broke the lead off at the winding, when I removed it off the mill.

Allen, I'm watching your conversion very closely. The only change I would make, if i decide to convert, is to use a 2 pole (3600 rpm) motor, since most of what I do is with aluminum

[Al_The_Man]

If using a VFD why not go up to 120Hz with a 4 pole?
Al.