Messages

161

General Mach Discussion / Re: PWM or step and Direcrtion to control inverter drive ?

« on: April 07, 2015, 04:55:35 PM »

Thanks for the reply,

I'm trashing the Chinese break out board and today I spent my Pocket Money on a Ethernet Smoothstepper with a Motion Control breakout board.
I like the Break out board because the Smoothstepper sits nicely atop it.

So thanks for the advice. I'll have to wait a few days for the delivery but in the meantime I can look at my encoder disc and get that sorted.

I do believe that you mentioned in another post that only one slot is all that was needed.
Reading the Mach Lathe manual Art says 3 narrow slots and one slot 50% larger than the other 3.
If I only need one slot then the encoder disc on my spindle shaft should do as it is. It even has the original mount for the slotted opto! (picture attached)

George

162

General Mach Discussion / Re: lathe threading

« on: April 01, 2015, 05:17:46 AM »

Hood, I'm contemplating going down the Smooth Stepper route and may buy the USB version.
What other boards are available as Break out and Spindle control.
I see that CNC4PC have a terminal board that plugs directly onto the Smooth stepper.

George

163

General Mach Discussion / PWM or step and Direcrtion to control inverter drive ?

« on: March 31, 2015, 04:16:13 AM »

Which is best ?

My Break out board supplies PWM output 0-5v

If I use this to control my Inverter drive hence my spindle speed I will need to put the PWM through a PWM to 0-10v circuit to the input of my Inverter drive.

Alternatively, I could use one of my axis drives via an off the shelf Step/Dir to 0-10v to the input of my inverter.

Any advice on which is the better method?

Additionally, my BOB has two outputs for Fwd and Rev. I'm assuming if I use the second method I would not need these ?

George

164

General Mach Discussion / Re: Hall Effect or Slotted Opto?

« on: March 29, 2015, 03:19:53 PM »

Thanks for the replies,
I have ordered some 3mm neo magnets and will glue that to my disc which is attached to the shaft as in the picture. I should think I will get a better resolution if I attach it close to the original holes. ?


Thanks

George

165

General Mach Discussion / Re: Hall Effect or Slotted Opto?

« on: March 29, 2015, 11:05:09 AM »

Thanks gents,

Ok, looks like its the Hall Effect route I'll adopt, thanks for the advice.

Rich, excuse me if I'm being a bit dumb. I'm not sure by what you mean when you say 'You don't use the BOB' Are you suggesting that I don't use either the Hall or the Opto at all? Are we relying on the 0-10V input to my Inverter drive.
I will be using this on a Lathe (TCL160) so I will want to do some 'threading'

George

166

General Mach Discussion / Hall Effect or Slotted Opto?

« on: March 29, 2015, 08:45:04 AM »

My break out board calls for a Hall Effect sensor to get the spindle pulses into Mach3, however my old TCL160 under conversion already has a nice big encoder disc mounted directly on to the end of the spindle shaft.
It has 100 holes on the inner and 1 slot on the outer ring and uses two slotted opto switches.

I really don't want to use magnets mounted onto my encoder ring for fear of introducing a balance issue.
Can I use the slotted opto switches with my break out board. And if so can you suggest a hook up method.
I have attached some pictures which may help.

I understand I can then calibrate the spindle speed by running the spindle and comparing the speed from Mach3 with the actual speed recorded by an electronic speed gauge and then applying a difference offset into Mach 3. Is that correct?

Many thanks

George

167

General Mach Discussion / Re: PWM Spindle Control using Mach3 - How I did it

« on: March 24, 2015, 09:34:30 AM »

Thanks for your reply Krypton.

On this Lathe (TCL150) the way the tool turret and tools are designed the Surfacing tools come into contact with the workpiece from above. This is where the reverse rotation of the spindle motor is needed.

I assume also that accurate control of the spindle speed is required where 'Threading operations' are carried out ?

George

168

General Mach Discussion / Re: PWM Spindle Control using Mach3 - How I did it

« on: March 23, 2015, 09:24:47 AM »

I could use some help please in hooking up my Spindle motor to my breakout board.
This is ongoing from my conversion of my TCL160 which has a Mitsubishi FR-Z024 0.37k fitted.

The original Documentation from the TCL160 shows these connections were used.

STF (Fwd) to pin 5 on my new board
STR (Rev) to pin 7 on  my new board
5
2
P24 (Looks like pin SD which is common) Output shutoff, how is this handle by Mach3
MRS/RT This is marked as 'Boost' on the original TCL Manual (What is the purpose of the Boost)

I have included some diagrams and would appreciate help on the correct hookup.

169

General Mach Discussion / Re: Boxford VMC 190 CNC Mill and TCL 160 CNC Lathes

« on: March 21, 2015, 09:54:13 AM »

I'm about to remove all the gubbins from my TCL160 this afternoon and start the conversion.
I will fit a new control PCB and use  3 new MSD542 micro stepping axis controllers.

The book says the steppers fitted are half stepping mode giving 400 steps per revolution. The windings are wired in parallel. I think for ne I will leave them fitted although I do have 3 spare 2Nm steppers I could use. Does anyone know if these are ball screws that are fitted to the X and Z axis ?

If I take it steady, I will leave the control electronics intact and just disconnect the stepper motors from the main pcb and hook them up to my new controller. That way I can still have control of the Tool turret and the Spindle motor from the original front panel of the machine.

Any pointers will be very welcome.

170

General Mach Discussion / Re: Boxford VMC 190 CNC Mill and TCL 160 CNC Lathes

« on: March 19, 2015, 06:25:12 AM »

Just signed up for ONshape, it looks good indeed.

George