[SWATH]

My spindle direction issues are in the manual setting. When I first power the machine on the LCD says "FOR" but when you press spindle start it goes CCW. That is what I am trying to rectify. I want it to spin CW when it reads "FOR".

As far as the power issue I don't know what to think. Nothing else in my house has any problems with the power. If there are large transients I would think my computers and microwave and TV, and even my computerized washer and dryer (which are 240v 30A) would be damaged, but they are not. Also everyone I talk to about the issue who is knowledgeable about electricity scoffs and says any thing designed for 220/240 will not be hurt by 250v. So if the machine is damaged by supply power that is within spec (my state code goes up to 252v) then it definitely needs to be made more robust and not just conform to the California code. Especially considering this machine is marketed to single phase residential users, which I take it may or may not have power as clean as commercial power. The EE from above had suspicions about the board being damaged by my high line voltage but was also curious why it wasn't made more robust to handle it. He is still thinking it may be a design issue with the board or perhaps a faulty component.

[SWATH]

I too had problems with my spindle. It ran forward in manual mode and backwards in Mach3 (cnc mode). My machine is using the Smooth stepper breakout board (it kept having problems when I ran without it). Phil sent me the Mach3 configuration code for use with the Smooth stepper board, and that cleared everything up except the spindle running backwards part.

What problems were you having without the smooth stepper board? I contemplated getting that on purchase but I didn't really know what it was for and was told I probably didn't need it because it was for computers that didn't have a parallel port.

[SWATH]

Also the EE commented on how he appreciated that it had a BLDC servo instead of a VFD. I asked if the the BLDC was better and he said emphatically "oh yeah, absolutely". I didn't really get the explanation why it is theoretically better. Can someone explain it to me, I'm curious. All I know is that the brushless motor version of my impact driver was way more expensive than the brushed version and it is much smoother in operation with better battery life and more power.

[SWATH]

Just got word from Phil on my axial power supply board here is what he said:

We have received and completed inspection and repair of your power module
for the axial drives. The bridge rectifier on your board was damaged and
replaced. The board is now operating properly and has completed both
burn-in test and load tests, and is ready to be returned. This would be
the expected failure mode when exposed to high voltage or transients (or
in your case likely both).

[billm01830]

I need help with programming helical tool paths on an Okuma. I use master cam X5. The machine alarms out when I try this type of tool path. I've tried many diffrent types of lead in and out paths with no luck.
Thanks
Bill m

[allenj20]

Well I can try and explain it....


Brushless linear DC drive is a system that uses permanent magnets and a fixed armature and hall effect sensors and a microprocessor controller to switch the phase of the windings. It is considered linear because it develops maximum torque while stationary and has linearly decreasing torque with increasing speed. The controller uses firmware and feedback from the hall effect sensors to decide which windings to energize next and uses a PWM signal to the motor to energize the windings.

The advantages over brushed DC motors are there is no mechanical contact between brushes and a rotating armature and so a lot less maintenance is required. The also have more torque per pound than brushed DC and less noise and in theory more reliability. The downside is more complex control electronics. Our spindle controllers are really big microprocessor controlled DC chopper PWM speed controllers. This technology is the same as on a brushless RC car motor only ours are lot bigger and the speed controllers are a lot bigger and more complex. Likely it is the speed controller that is the weak link here.

AC motors and VFDs are a system that uses 3 phase induction motors with a solid state microprocessor based controller that also sends PWM signal to vary the voltage to the windings of the AC induction motor. The VFD takes in line AC voltage and rectifies it using a full wave rectifier in to DC voltage it then uses an inverter switching circuit to convert the DC back to a semi sinusoidal PWM wave that varies the voltage to control the motor speed. One upshot is you can use 240v single phase AC line to power a 240v 3 phase induction motor. When using a single phase connection the system must be derated power wise because the rectifier is only carrying part of the load. I think when I looked at it for a 5HP three phase motor you would get like 3HP running it on single phase. The AC induction motor requires more current and current losses to achieve power than the DC brushless. However the AC induction motor is very simple in design and very reliable and with a decent VFD is variable speed as well.

In theory the BLDC should be better linear torque curve wide range of available speeds reliable and quiet. The reality though is that the speed controller is fairly complex and in our case prone to breaking.

The reason I am considering a switch to AC and VFD is that I can get a Hitachi Sensor-less Vector VFD and AC induction motor pretty easily and it would be a system that is well tested and proven reliable.

You should probably ask your EE friend I am a geek but not the EE level of geek :rainfro:

[SWATH]

Thanks Allen,
That clarifies it somewhat. So does the VFD have an inverse sloping torque curve where it dramatically loses torque as the rpm increases?

[allenj20]

Depends on the drive there are voltage per hertz drives that are variable torque. They have a constant torque up to their base speed at which point field weakening kicks in and torque drops off eh picture is worth a thousand words. Here ya go this is for voltage per frequency VFD

http://www.hacksbot.com/storage/Scre...03.51%20PM.png

Sensorless Vector VFD drives are different and have a curve similar to DC drives with max torque near zero speed and a more or less linear response. I can't find a good curve for one though. Naturally sensor-less vector VFD costs more money.

[ROCKYMTN]

Well I can try and explain it....


You should probably ask your EE friend I am a geek but not the EE level of geek :rainfro:

I'm a EE and you did a fine job of explaining!

The BLDC uses powerful rare earth magnets in the rotor so the magnetic field is already there whereas in a AC induction motor, that field needs to be generated by the rotating stator field. This makes the BLDC more powerful pound for pound and allows for a lighter motor to be installed on the z axis. Also, a BLDC has better torque at low speeds as compared to a VFD/3phase motor setup.

As you said, the electronics are much more complicated for the BLDC.

[mechie]

What problems were you having without the smooth stepper board? I contemplated getting that on purchase but I didn't really know what it was for and was told I probably didn't need it because it was for computers that didn't have a parallel port.

I don't quite know what the smooth stepper is for; it came with my machine (I bought the integrated computer, which has a serial port and usb). Without it my steppers would jump whenever I switched from CNC mode to manual. Phil said I may not have a clean ground, but once I was able to use the smooth stepper again my problems went away.

[allenj20]

The smooth stepper is a USB motion control device for Mach3. It takes data from mach via USB and turns it in to a a steady pulse train for stepper and servo motors. It can perform the function of two parallel ports for mach and offloads the pulse generation from the host CPU. It can generate a high quality high speed pulse stream. And you don't need a parallel port on your controller.

I like mine though I don't think it is strictly necessary.

[ROCKYMTN]

This is a Mach3 issue. You have to issue the command to stop the spindle (M5) then enter M3 (or M4) and the new speed in the G-code. Otherwise, Mach3 will mess up the speed. FYI, the feed override in the lockdown version of Mach3 doesn't work either. It works in the beta version of Mach3, but that version didn't jibe well with my machine so I went back to the lockdown version.

Thanks for the confirmation !

[mcphill]

I agree with most everything you said, but the fact that your computers are fine is irrelevant. They run off DC, created by the AC/DC power supply (the first thing the AC line runs in to), which has it's own built in surge suppression. I doubt anything in your house (except maybe your other shop equipment) uses "raw" 220/240 for anything close to critical. Your clothes dryer uses 240 for the heating elements, that would probably take 300V and be fine...

Again, I do think it is a Mikini issue, and it should be able to take "approved max" limits for any region at least in the USA. That means peaks of 254 V or even higher. To "put the burden" on the end user to make up for any variation in an incoming utility over which they have no control makes no sense to me...

[allenj20]

I'm a EE and you did a fine job of explaining!

The BLDC uses powerful rare earth magnets in the rotor so the magnetic field is already there whereas in a AC induction motor, that field needs to be generated by the rotating stator field. This makes the BLDC more powerful pound for pound and allows for a lighter motor to be installed on the z axis. Also, a BLDC has better torque at low speeds as compared to a VFD/3phase motor setup.

As you said, the electronics are much more complicated for the BLDC.

Thanks I have to admit though even after reading the description of how a sensor-less vector drive works I have decided the principle is just FM (fricking magic)

[SWATH]

Has anybody got their spindle problems fixed yet?

[slowtwitch]

Has anybody got their spindle problems fixed yet?

Currently, my spindle motor and controller are at Mikini. Monday, I sent my front panel for testing

[SWATH]

Me too still waiting.

[SWATH]

I just got word that my spindle drive board finished testing and that no problems were discovered with it. They want me to send back the spindle motor now, so I took it off and am sending it back tomorrow.

[slowtwitch]

Good luck. When my controller, spindle motor and front panel come back from Mikini and things still aren't working, i'm going to look at installing an AC motor and vector drive. It's just taking to much time to get these things sorted out and my start up/retirement business is on the brinks, thanks to no product that the mill was suppose to make

I've done everything possible on this end, I had my grounds and voltages checked out and all looked good. I also was lucky enough to aquire a 7.5kva isolation transformer( a freebie!!!!!) and had it installed...and as per Phil, had an equipment protection device installed. These things are expensive !!!! After the transformer and EPD install, i had everything load tested. Again no problems.

The only positive thing to come out of this is that I was able to work on my CNC lathe and it's just about done and it runs Here's the link if your interested..

http://www.cnczone.com/forums/vertic...p_rebuild.html

pete

[SWATH]

I was kind of surprised that they said the drive is working properly because the EE tested the motor and deemed it ok. If they say the motor is working fine I don't know what to do at that point. It clearly does not work properly at my house and the EE tested my power and determined it to be ok so I'm not sure what to do about it. Nice lathe, I imagine I'll need one of those before too long, but first I need a functioning mill or like you I'm dead in the water.