Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: Graham Waterworth on November 03, 2006, 02:01:54 PM
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Hi All,
I took the plunge and bought the Boxford Mill, its a very tidy machine, very little use.
Now I am in the throws of converting it to Mach3, most of it is straight forward enough but the DC spindle drive is a bit of an enigma.
From the pictures below can anybody tell me if I can use this from Mach.
It looks to have -10V and a 10V connector on the green PCB but I can not find any drawing or info about the setup.
It looks as if it may use a relay to change direction.
Any help much appreciated
Graham.
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Hi, Graham
I didn't see any speed adjust control in your picture's.
If it's a speed reo-stat and with some luck 0-10 / 0-5 volts controlling the board, Be carefull checking as some Mfg's float the 0-10 at line potential.
Put on a speed sensor pickup, get one of those 0-10 volt speed board's, thay have a lot of caution's in there Doc's.
You may be good to go.
Post more picture's. let me now.
Hope this Helps, Chip
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Hi Chip,
since the first post I have found out a bit more about the drive.
It works with an analogue 0-10V input to control the speed, the direction is controlled by an external relay.
I have found this bit of a schematic but I am not sure its got all the detail I need.
Any ideas.
Graham.
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Hi, What you need is something like this at http://cnc4pc.com/Variable_Speed_Control_Board.htm or http://www.homanndesigns.com/DigiSpeedXL.html
Regards
John
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Maybe but the ones you suggest work with a 24V output from the dc drive, this one seems not to have one.
Or am I wrong?
Graham.
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Hi Graham, If your controller has a 0-10v for speed regulation you can connect one of those converters to run your controller from Mach3.
From the circuit you posted it looks like there is a 0-10v connection, measure the voltage on the 2 wires (high voltage precautions taken) and adjust the spindle speed, if the voltage changes from 0 to 10v then this is ideal.
The first converter uses step and direction signals from Mach and the second one can use a verity of ways.
The second converter can use PWM from Mach and this is ideal for using G96 on a lathe.
Have a read of there literature on the converters.
cheers
John
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HI Graham, either of those will work fine. The digi speed xl seems a little more feature laden but the cnc4pc one would work too. The 24 volt that you were looking at is kind of mis leading. It is simply the common on the relay the ccw is the nc side of the relay and the cw is the nc. He called it 24 volt because that is what most vfd's use for their switching input voltage.
Looking at your pictures and your schematic it will be no big deal to get mach controlling your spindle with either. I would be happy to help. I also see in your pic of the 0- to 10 board the little white ic is a optocoupler, that means that it is indeed isolated from the 240 vac coming in to the other pins of that board. If you don't care about reversing the spindle then it is just a couple of wires to hook up if you do we just will need to dig a little deeper and figure out what voltage that reversing relay needs to trip it. We might need to add another relay in the mix just to keep mains (possibly) of of the speed control board. either way no big deal, you lucked out on the speed controller for your lathe they couldn't have made it any easier to interface with mach.
Chad
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Hi Chad,
Thanks for the offer of help, I need it.
I am a mechanical engineer and software developer (payroll, invoice, database etc), my electronics is limited. Basic electrics is no problem.
As luck would have it I have a ModIO and a DigiSpeed XL, so it would be nice to use these, by the way this is a mill so I will want to reverse the spindle for tapping.
I have had a look at the switching relay (RL3) and it is a 24V coil
The power rail in the machine has 5, 12, 24, 40 volt dc.
Thanks
Graham.
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Just let me know when you are ready to put it in and we will figure it out
Chad
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Thanks Chad,
It will be about a week, I am just getting all the crap out of the control cabinet at the moment.
Quick question :-
What is the purpose of a 80mh 6A choke ?
Thanks
Graham.
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More than likley is is a high frequency snubber and back emf protecter when the direction relay is opened. It is there to help protect the pwm dc spindle driver and cut back on rf noise emission.
Chad
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Thanks,
best leave that in then.
Graham.
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HI Graham,
Sorry for the delay, I am biding on a $60k project and it has taken all of my time lately.
Any way here it is and i think it should work.
You will have to pick up at your local electronics store a 12 vdc wall plug. according to peter you will have to isolate the 12vdc for the speed controller ( on the motor side) from the common on the machine. Personally i think it would work just fine but he says not to so better not. I did not show wiring from the jumper that connects to mach because i don't know how you want to hook it up, All of that is covered in the manual and should be pretty straight forward.
To change direction all you have to do connect the dir change relay, put +24vdc on one side of the relay connect that to the com then gnd the normally open. When mach sends the dir change the relay on the board will close and that will close the big relay going to the motor and reverse the direction. Depending on what way the big relay is wired you might have to reverse the wires, if forward is reverse and reverse ids forward.
If you have any further questions pleas drop me a line.
Chad
Here is the sch, it is quick and dirty but should get you by...
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Thanks Chad,
the spindle is now working in manual mode, I just need to sort out the computer control side now, my rotation sensor disk may have too many holes in it, its got 50 2mm dia holes on a 60mm pcd.
Graham.
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Hello Graham and all.
I'm from German and this is my first Post in this great Forum. I read your Posts to the Problem with the Spindle Drive.
I have the same Drive (it's an Lenze 534) on a Boxford 160TCL CNC-Lathe, it works with a Lenze DC-Motor 180 Volts.
I use Mach3 and i have the same Problem: How can i change the direction of the drive?.
I use this Board:http://www.campbelldesigns.com/breakout-board.php and the Spindle Control
http://www.campbelldesigns.com/mach-spindle-speed-control.php. With the second Board i can control the
Spindle Speed with an analogue 0-10V input. It works well, but i have no Idea how to change the direction.
The Spindle Control Pcb have the same N/O COM N/C pins like the DigiSpeedXL. Did i need two relais
with 24 Volts (one for Fwd and one for Rwd) ore can i do it with one relais? Please excuse my bad English and i
hope you understand what i mean. I have no Problems to read in English but it's difficult to writhe in English.
Best regards, Dietmar.
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Did you ever sort this Spindle drive out?
My Boxford 160TCL has the same drive and uses a relay to switch the direction.
I was planning on using the speed control on a CNC4PC C11G breakout board to control the speed, will this work?
If you did sort it, How did you connect up the relay to get the direction to switch?
Also how did you connect up the spindle encoders? The lathe has 2 encoders on it, one with 1 slot and another with loads of holes (I have not counted them yet)
Thanks
Simon
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Graham - and Ditmar
I don't think you need to get too involved in how it all works. The important thing for you is What makes it work. You say it is a 10v dc signal that controls the speed and a relay controls the direction.
If there is easy access to the reversing relay already fitted, then this can be controlled by a second relay in turn controlled by the Mach3 M3 or M4 signal (which would cut out any chance of electrical interference). Ditmar - as far as you are concerned - the same question - what changes your direction now - is it a switch, is it a pushbutton - etc. The simplest way to wire anything up is leave it as it is, and just alter the control - so if you have a switch - fit a relay that closes a switch in it's place. I have my four additional outputs on Mach driving four relays ( via a Darlington array chip) - a single chip that can drive all four relays direct from the computer. These relays are (at the moment) activated by M3 and M4 (to suit my Omron inverter). I am only using two at the moment - the other two are spare possibly for coolant and anything else I want to control.
As far as the control voltage is concerned, a simple digispeed card will convert the PWM signal output by Mach 3 into a control voltage of whatever voltage you want. The two halves of Digispeed are electrically seperate, the input side is powered from the computer electronics at 5volts. The output side power is taken from your controller which in your case shows 10volts. Digispeed therefore puts out a signal from 0v to 10v to control the speed.
The diagram you posted shows that the 10v supply is isolated from the rest of the drive circuitry - so I think you are on a winner - but I can't quite work out where the signal goes in to control the speed.
Does the system fire up as it is - i.e. does it run the spindle - I assume it must work - so how do you control the spindle speed now. If it is a manually potentiometer then you could replace that with leads to digispeed and it would run fine.
It is identical (and probably from a similar era) to my Omron (although mine uses 3 phase AC drive) but the controls are identical.
I have Digispeed fitted and you are welcome to have a look.
As far as the speed indicator working - mine is just a single strobe each revolution, - on the index pin. This is nice and simple. The lads who have used multiple slots had a bit of difficulty, and, I understand, one of the slots should be wider to index the position. The method you use is not important - both work. The important bit is the voltage that your indexer puts out. This should be TTL compatable so you can feed it into Mach3. I use reflective sensors - onto mirrors stuck on the spindles - with a disc you can use straight through sensors. Once you get the output voltage right you will have no difficulty.
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Hi Jim,
thanks for the information, the job was finished in November 2006, I think its SimonD that needs the info.
Regards
Graham.