Hello Guest it is October 15, 2019, 07:55:13 AM

Author Topic: Boxford 160TCL  (Read 38738 times)

0 Members and 1 Guest are viewing this topic.

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #10 on: April 11, 2008, 04:55:12 PM »
Having looked at the electronics and tried to remove the Z80 board, it looks like the two are interdependant. I am not sure it is worth the trouble!

So...

I have been thinking of getting the Gecko 201's for the X and Z axis. Is there any need to go to the 210? or better spec? Why would I want to select the microstepping? is it down to the limit of number of steps MACH3 can output, 25Khz??

The gecko drive seems a bit of overkill for the turret as the operation of it seems fairly dumb. It looks like "rotate clockwise for x degrees and the anti clockwise for y degrees which then stalls the stepper motor?
Is there a simpler cheaper solution I should be looking at for the stepper driver?

I see that CNC4PC do a specific breakout board for Geckos called the C11G ? I could't find any difference in the documentation, anybody got any idea what the difference is?

Simon

Re: Boxford 160TCL
« Reply #11 on: April 11, 2008, 06:15:09 PM »
Simon,

Shame about the Z80 card, it would have allowed you to  get the machine running with Mach, without too much expense.
Unless you have a need for adjustable stepping rates the 201 will do fine. I went with the 203V because it is idiot proof  :).
If you are going to use the turret, then although it is fairly simple to drive in software, the stepper still needs a good driver to avoid loosing steps and if you have a power supply for X and Z then you might as well use it to drive the turret. I now only use the tool plate, as in the video.
The C11G is buffered but not fully opto isolated, not needed for the Geckos as they are. If you want total opto isolation use the C11.

Ian

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #12 on: April 11, 2008, 06:53:53 PM »
Ian,

I will have another look at the stepper board over the weekend but when I just disconnected the Z80 board, the stepper board wouldn't even power up. The entire front panel is also connected to the stepper board and even that lost it's functionality.
If I had a wiring diagram then I might be able to figure it out but it isn't immediately obvious what is wrong. What I don't want to do is spend ages figuring it out only to find that the board packs up after a couple of months and I have to rip it all out anyway.

I got the lathe for a bargain price so I don't mind putting some money into it. I guess I could go for a 201 for the turret and 203V's for the main axis.
Reading the Gecko site, I did like the way the 203V's automatically transition from microstep to full step depending on the speed, that is a nice feature.

Does your machine have the Lenze inverter in it still? Mine has an odd board mounted onto the same plate as the inverter and it obviously has something to do with it but I can't work out what it does. I spent most of tonight trying to figure out the contactor wiring and how it switches the spindle direction. I'm still not sure I fully get it!

Simon
Re: Boxford 160TCL
« Reply #13 on: April 12, 2008, 07:36:34 AM »
Simon,

My Boxford had a GEC Gemini DC controller that failed, so I replaced it with one from BEEL:-
http://www.beel.ca/smcmanual.pdf
Your Lenze one should be very good quality and design.  Have you found a manual for it? I don't think it will be an inverter, as they are used for AC drives and I think that yours is DC, have a look at the motor plate. The transformer looking device is a choke (an inductor), wired in series with the armature supply to slow the rise time of the current.

Assuming DC, it is not a simple mater to reverse it at speed. Just throwing a switch to reverse the voltage on the brushes will cause the back emf from the motor to be added to the applied voltage and will fail the motor and/or driver. Lots of amps will be gererated, which would cause arcing of the brushes and on any changeover relay. So, what is usually done is that at a reverse command, a relay drops out cutting the drive current to the motor and shorting the motor terminals with a low value, high wattage, braking resiistor. This brings the motor to a stop. Either a time delay or a motor voltage sensor is used to make sure it is stopped. It is then safe to start the motor in reverse with another relay. My 125 has the two relays mechanically interlocked to avoid forward and reverse being energised at the same time.
Your Lenze controller may be more inteligent and have all this built in so that it is only a matter of applying a control voltage to a forward or reverse terminal. It should also have terminals for speed control. This usually 0-10 volts DC with a centre tap so as to connect a 10K ohm variable resistor (pot). You can then use this voltage to power the speed control on the C11 card and the output from the card to the centre tap on the motor controller. If it is an AC drive, the inverter will have all this as standard  and will be programmable by inputting various parameters via a keyboard.

Unless you must have rigid tapping or use a fixed die for threading, just use a pot to manually control the speed to begin with. If you want variable speed control from Mach, you need to replace the timing disc on the back end of the spindle with only one wide slot - see the Mach turning manual. You might be able to use the Boxford slotted opto switch.

Have fun!

Ian
 

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #14 on: April 12, 2008, 08:00:11 AM »
Ian,

Many thanks for all your comprehensive replies, it is much appreciated...

Mine is indeed a DC drive. I have the PDF manual for the drive from here...

http://akb.lenze.de/AKB-englisch/infopool.nsf/1429b1338a70e30b41256a2900343844/b347039433d8d32bc1256d880037c499/Body/M2/530_Speed_controllers_1202_EN.pdf?OpenElement
I have yet to digest the information though.

It is identical to the one in this post...
http://www.machsupport.com/forum/index.php/topic,1645.0.html
Even the odd external board by Simpletron is the same.

I bit the bullet this morning and ordered 3 off 203V Geckos and a CNC4PC C11G BOB and while I was at it I ordered their C3 - Index Pulse Card as it looked like is might do the spindle index and was cheap enough to add on just in case.
I figured the extra £15 for the peace of mind of the 203V against the 201 was worth it.

Do you use any of the original control panel on your boxford? Mine is a complex affair with a full PCB behind it with all sorts of components on it, I think it might be just easier to make a new panel!

Thanks
Simon
Re: Boxford 160TCL
« Reply #15 on: April 13, 2008, 09:35:46 AM »
Simon,

That Simplatrol board is probably the opto isolator for the spindle drive card and since you will have this on the C11G, it is not needed. Mach can be configured to send a contol voltage to change the motor direction with M05 and M03/04 and I assume that you could also detect that the motor has actuall stopped and then engage the chaneover relay.

I only use the start and emergency stop switches on my panel. You would need more I/O from either a second parallel port, serial port or SmoothStepper USB, to get all the switches to function.

The original steppers will probably function OK but the are old technology. I used 2 stack 23 size from Motion Contol Products.

Ian

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #16 on: April 13, 2008, 01:49:33 PM »
Ian,

Reading the Lenze manual seems to imply that the speed controller handles the slowing down and stopping of the drive during the changeover. I will have to see when the BOB arrives.

I have some 2 stack 23 size steppers from Motion Control Products on my mill. If the original ones on the Boxford are no good I will try them. I have been disapointed with the torque from them MCP steppers and have even installed a 3 stack one on the Z axis of the mill but I suspect it has more to do with the 24v power supply and the StepMasterNC controller. I look forward to seeing what Geckos can do! My StepMasterNC controller couldn't even make a single stack stepper turn my rotary table with any reliability!

Simon

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #17 on: April 14, 2008, 05:01:31 PM »
Well, the mechanics have cleaned up nice!
Re: Boxford 160TCL
« Reply #18 on: April 14, 2008, 05:43:25 PM »
Simon.

Looking realy smart! Where are the go faster stripes? :)

Ian

Offline SimonD

*
  •  143 143
    • View Profile
Re: Boxford 160TCL
« Reply #19 on: April 20, 2008, 03:33:17 AM »
Does anybody have a wiring diagram for a Lenze DC spindle?
There are 5 wires to it...
I know what 3 of them are for. Two are for the main motor connection and can be reversed to reverse the direction, the third is the ground connection but there are also 2 yellow wires which were originally connected to the guard switches and e-stop button.
I can only imagine that they are an electromechanical brake? I have tried shorting them together but they don't seem to do anything, presumably they need a voltage to be applied? But what voltage?

Thanks
Simon