Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cncfreakcncfrea on March 29, 2013, 09:09:05 PM
-
Hi,
This is my 1st cnc lathe conversion and it is almost complete apart from the spindle motor which I'm not sure whether to use AC servo or other, need some suggestion on that, currently AC servo is mounted on.
The lathe is a BVB25L:
(http://i1220.photobucket.com/albums/dd459/happytriger2000/Machinery/BVB25L%20Lathe%20cnc%20conversion/DSC05803.jpg)
It is driven by 2 DC servo 24V with absolute encoder for X axis and Z axis, 1 ATC turret with Stepper motor for tool change, and the spindle Motor = Mitsubishi HC-SFS352K, Driver = MRJ2S-350A.
Currently I'm facing problem with the AC servo drive(s), there are 2 MRJ2S-350A and I think both aren't working properly, those were bought used, I'm looking for an alternative.
-
Very nice job so far.
I like the looks of the turret, did you make that also ?
Good work !
Russ
-
Hi Russ,
I got the design plan from cnczone can't remember who provided it was ages ago, the measurement was all in Inches, I re-drew it all in mm.
thanks
-
What is the problem with the drives?
Hood
-
Hi Hood,
As I switch on the drive the motor spin really fast and kept increasing until AL appears and stop this happened within 5 secs.. I get AL 52 and sometime AL 31, then I tried initialise the drive ---> PR182 -->0012 switch off then switch on, set my own PR settings but still getting Al. To proof the driver is faulty I use the same Pr settings on a MRJ2S-100A, it worked fine.
I think the easiest way is to put back the original AC motor that came with this lathe and add a encoder somewhere....
-
Also I forgot to say, if anyone out there has a BVB25L lathe, can I ask you to take a snapshot of the inner side of the Box where the gears are and send it to me, during cnc retrofit I took apart most of the gears and I wish to put some of them back in place but forgot where they belong,
thanks
-
Sorry not quite clear but think you are saying you have tried the motor on a bigger drive and the motor is fine?
Do you have the drive set to the correct mode? I have not used these Mitsu drives so not sure how you set them up but maybe there is an option to reset the eeprom to factory settings, if so then maybe that will clear something that is causing a problem.
Do you have software for connecting these drives to a PC?
Hood
-
Factory setting = Pr182-->0012, then power off power on.
The software is called MRZJW3-Setup161, I have installed it but haven't used it yet.
-
Tool turret video:
http://s1204.photobucket.com/user/cncfreakcncfreak/media/BVB25L%20cnc%20conversion/M4V05238_zps2f64eba2.mp4.html
-
Just to confirm, you tried this motor on the other drive and it was fine?
You used the same cables when you tried on the other drive?
Reason I ask is because it sounds like the motor phase wiring is not correct as it will likely take off when that is the case.
Hood
-
There are 2 MRJ2S-350A drivers both purchased as used, 1 HC-SFS352 AC servo Motor, and 1 HC-SFS352 with S logo at the encoder cap (this one purchased 2 days ago). From the picture posted at the beginning, the Motor is a HC-SFS352 (no S) connected to 1 of the MRJ2S-350A, when switched on the motor speed up fast + acceleration then stop as AL on the LED screen appeared AL 51, since it was purchased as used I have no idea what had been set previously so I restored back to factory setting by going to Parameter 182 ---> use up & down keys tilll it display 0012 then press "set"--> power off drive then power on drive. Now I know this drive is at deffault settings, usually from here onwards with all the cable connected correctly, CN1B (VR knob for speed control), CN2(Encoder), 3ph power from the main to Driver's L1 L2 L3, and U,V,W to AC Servo Motor's Power, I should be able to control the speed of the Motor via the VR having the Pr 0 (0002) and 1(0001) set correctly, but the Motor still doing what it used to, another strange behaviour was when CN1B is not connected tot he Drive, the motor still be able to spin which shouldn't be. The same thing happens to the other MRJ2S-350A Drive, so I think I have purchased 2 faulty drives, to proof this is faulty I unplugged CN1B (VR speed control knob) and plug it to another Mitsu drive MRJ2S-100A (This is a working Drive) to test it, as I turn the VR knob the motor increase or decrease speed, this is what a genuine Drive should do.
I used the same cable for all drives.
-
Ok think what you are saying is you have only tested the CN1B connector on another drive?
Have you tried changing round the R S T wires?
Do you have to set up the motor parameters in the servo drive? It is normal for AC servos that you have to load a motor profile unless the encoders are smart encoders and contain motor information.
Hood
-
Changing R S T wires, would it make difference if I change U V W wires?
Have a look at this drive:
http://s1204.photobucket.com/user/cncfreakcncfreak/media/BVB25L%20cnc%20conversion/M4V05805_zpsbc953515.mp4.html
This is a MRJ2S-40A, on the right hand side is a speed control VR connected to CN1B.
I will do a final test for the MRJ2S-350A drive tomorrow.
-
Yes RST/UVW shame thing, just some drives call them one and some the other.
Hood
-
Hello Hood,
I had the AC servo drives fixed, It is running fine now.
I was told that the RST does not matter but the UVW have to be connected correctly:
(http://i1204.photobucket.com/albums/bb407/cncfreakcncfreak/BVB25L%20cnc%20conversion/MRJ2S-Sinalandwiring_zpsc991e187.jpg) (http://s1204.photobucket.com/user/cncfreakcncfreak/media/BVB25L%20cnc%20conversion/MRJ2S-Sinalandwiring_zpsc991e187.jpg.html)
Video clip:
http://s1204.photobucket.com/user/cncfreakcncfreak/media/BVB25L%20cnc%20conversion/M4V05905_zps3d87a359.mp4.html
-
http://www.youtube.com/watch?v=DAv-8gquj0A&feature=share&list=UUpqKQljKkdBanamxgJSCuog
-
Looks to be working well :)
Nice finish as well, what is the material?
Hood
-
The material is a piece of Brass rod.
Will show a video clip of Visual Turn simulation sometime later.
-
Yup, looks good. :)
Brett
-
Here is a video of Visual Turn to Mach3 Turn:
http://www.youtube.com/watch?v=pVPIHbZNI3k&feature=share&list=UUpqKQljKkdBanamxgJSCuog
I'm not getting much support from Mecsoft forum, so I will ask my questions here:
I'm looking for someone who has used Visual turn for help, please drop a note here if you use Visual Turn.
From the video link above, can someone point out if I have Mach3 setup correctly?, I'm a bit confused on cnc lathe's X axis and Z axis Positive and negative direction, for X axis, is it correct that when the cutter moves away from the stock is Negative? and For Z axis, when moving away form the stock is Positive?
Need some basic intro. on cnc lathe.
thanks,
-
X moving away from centre line is positive and Z moving towards tailstock end is positive. If you think of the X and the Diameter of the part, X0 would be centre X10 would be 10mm Dia, X20 20mm Dia etc etc.
Normally you set your work coords for Z to zero at the end of the stock and thus all cutting in Z is negative values. It is the same as a mill or a router, normally you set the top of the material as Z0 and all cutting in Z is negative, just think of a lathe as a mill lying down on its back and it should help.
Hood