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Author Topic: CNC4PC C11G Analog Output Spindle Control  (Read 15232 times)

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CNC4PC C11G Analog Output Spindle Control
« on: December 01, 2009, 01:02:51 AM »
Hi All,

OK, the next step is to get the spindle working with Mach3, now that I have the index pulse properly setup to read the speed.  I have a C11G BOB from CNC4PC and I am not sure how to proceed, here are my problems:-)

1- The VFD I am using ( a 15HP GS3 from automation direct) has an analog output supply of 10V at 20mA max.  The C11G has a required input of 12V @50mA.  Do I really need another isolated power supply?  I feel like I have about enough in that control panel...  24VDC, 24VAC, 12VDC for the drives, 60VDC for the servos, and on and on.....

2- Ive read some not so encouraging things about the C11G's analog capabilities after purchasing it quite some time ago, if I go to the trouble of setting up another PS, will it even work?  Has someone out there had success with it?  I have 4 of their boards going right now and all the other functionality seems OK, although I had to return one for workmanship issues (pins bent over on IC) and they always look a little funky right out of the box...

Does anyone have any suggestions as to how to proceed?  I am seriously considering just switching over completely to Peter Hommans boards and use the C11G in my other lathe which is currently BOB-less.

I've recently received a big order for parts and am feeling the pressure to get this retrofit done, but want it done right :-)

Thanks for any suggestions,
Dustin




Re: CNC4PC C11G Analog Output Spindle Control
« Reply #1 on: December 01, 2009, 06:46:08 AM »
Can't really help you with  the C11G BOB, but I use Peter Hommans Digispeed board for lathe spindle control and it works very well controlling my VFD.

Peter
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #2 on: December 01, 2009, 07:17:27 AM »
Yeah its pretty simple setup,

1. The C11 F to V should only consume less than 10 mA.
2. The 10V input will be fine provided that in the VFD (pretty sure it will) has a selection for maximum input voltage. So its just a matter of setting up the BOB at its maximum frequency and adjusting the pot to output maximum voltage. will be like 9.3v for example (less than 10 as the maximum you have is 10). So then in the VFD the maximum input will have to be set to that value.

In the manual for the VFD there should be a part with input voltage vs speed that's the menu selection you are looking to set.
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #3 on: December 01, 2009, 04:40:19 PM »
Hmm, Having trouble with this.  I just hooked up the 10V to the C11G because I measured the draw at @ 14mA so figured it would not hurt anything.  It sort-of works, but it takes a long time for the speed to stabilize, and it seems to be super non-linear.  Also, it seems to have different speeds depending on if you are increasing S or decreasing it.  IN other words if you type in 50, then 100, then 150, etc you get different results than if you go backward from say 500 to 450, to 400 etc.

I have it set so that 8V is the maximum and this does not seem to saturate the F-V converter. 

Suggestions?

Thanks,
Dustin
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #4 on: December 01, 2009, 07:14:58 PM »
There are two things you can look at.

1. In mach under Motor tuning=>spindle your acceleration may be too low.

2. In the VFD there is a setting for acceleration/decelration if this is too low it wil be slow to respond also.

3. Also if 8v is the maximum output for a specific RPM then the VFD frequency will have to be set for it to spin at that RPM.

just go over
-mininum input voltage setting
-maximum input voltage setting
-acceleration
-decelration
-frequency at max/min RPM

take a little bit of going thru the menus to get it all set correct.
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #5 on: December 01, 2009, 07:56:55 PM »
Hmm, Having trouble with this.  I just hooked up the 10V to the C11G because I measured the draw at @ 14mA so figured it would not hurt anything.  It sort-of works, but it takes a long time for the speed to stabilize, and it seems to be super non-linear.  Also, it seems to have different speeds depending on if you are increasing S or decreasing it.  IN other words if you type in 50, then 100, then 150, etc you get different results than if you go backward from say 500 to 450, to 400 etc.

I have it set so that 8V is the maximum and this does not seem to saturate the F-V converter. 

Suggestions?

Thanks,
Dustin

I had a C11 that I used for spindle control for a while.  I also had a difficult time getting it to work as I wanted.  I never did figure out any kind of system to get it setup properly, but I did eventually get it working reasonably well.  It was a combination of settings of step pulsewidth and steps/unit.  Unfrotunately, I don't remember what the settings were.

Regards,
Ray L.
Regards,
Ray L.
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #6 on: December 01, 2009, 09:07:06 PM »
The hardest part is getting the numbers to match up having 500 RPM = 500 RPM and staying linear over the entire range, Takes some calculating and tweaking no real way around it.
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #7 on: December 01, 2009, 09:11:02 PM »
I have the C11g On my recently converted Lathemaster RF45 style machine. I have a belt drive conversion I made for it and run the machine with a teco sensorless vector drive off the C11g board.  THis is my first cnc machine and I built it myself with considerable help from people on the cnc zone and from a pair of very nice fellows off line. I have to say that I am very glad I went with the Cnc4pc board. It has made getting all these items working real easy. I have had no problems with the board and I am quite sure I had at least a few times wired things improperly before I got it working right and nothing went up in smoke other than a Gecko servo drive I really goofed on. My three phase motor is setup with a belt drive as I said and I am really enjoying the near six grand spindle speed. I have a two tier pulley setup and did my best to configure it in Mach3. It has been working very well for a couple weeks now and many hours of actual spindle time. So far the only issue I have found is that sometimes under a longish rapid movement for some odd reason the spindle seems to slow down a little and then once the rapid is done it goes right back to where it was. I bought myself a laser tachometer to check and verify my spindle speed settings and I am seeing speed accuracy of around plus or minus 20-30rpm. The higher the speed the more error but to be honest I have not spent a lot of time fine tuning the steps/inch or velocity settings in config for the spindle. It did take some time to find a sorta sweet spot that allowed me to show the max rpm at max selected spindle speed whilst still having the lower speeds to be close to actual. I think that there are actually two ways to wire it up but I do not remember how just now.

    Arturo tried to help me with this issue but I actually got some outside help before he got to me which was in the same evening. No fault of his just bad timing on my part. I gotta say that having infinite spindle speed control and on off in the software is a must have feature. I am now trying to figure out the simplest way to hook up some kind of relay for my flood coolant system off the c11g.  Only thing I wish is that these boards( all BOB's really)  had more inputs but I understand that is a feature of the parallel  port mostly. Again, true novice here talking so be gentle... peace

Pete
865-363-9218
Matospeter@charter.net
« Last Edit: December 01, 2009, 09:13:55 PM by Matospeter »
Re: CNC4PC C11G Analog Output Spindle Control
« Reply #8 on: December 01, 2009, 09:43:51 PM »
Sounds good, it takes quite a bit fooling to get the two matched up, the higher the speed then the less resolution you will have, I have it setup form 0-18000 RPM so the higher speeds are less accurate but within 100 so no big deal, unless you are using the two relays on the board then one of them will be fine for running the coolant pump pins 1 and 16 I beleive control those.

Re: CNC4PC C11G Analog Output Spindle Control
« Reply #9 on: December 01, 2009, 10:20:52 PM »
That is what I figured, but what kinda relay and electronics/ wiring do most of you guys use for this? thanks and peace...

Pete