[whiteriver]

I picked up a cute little VMC 100 a couple weeks ago with 14 tool holders 2 vices and no controller. The machine is is pristine shape.

I plan to swap out the 5 phase steppers for some servos I have laying around. I will be using a USB Smooth Stepper and Mach 3.
I pulled all the motors off including the DC spindle since I have no drives for them. Tomorrow I will make new motor mounts to attach my Automation Direct 750 watt Ac servos.

I do have a question about the proxy sensors for the X,Y and Z. How do you set Mach 3 up to use those? There is just a piece of metal inside the pulley to trip the sensor and every time the screw spins 360 it makes the switch.
All three axis have over travel switches that work like I am used to. Just the homes are confusing me.

I know this is a Emco forum but I am sure some have converted to Mach or Linux.

thanks,
Donny

[Jim Dawson]

The home positions can be offset from the pulse. The pulse from the prox tells Mach3 where it is, then you can move some distance from the pulse for the actual home position.

[whiteriver]

That's kinda what I thought. Since it say moves 1/4" every rev it would never know where exactly it is. It could take 20 revs to get to home or take 1. I'll just put new switches on there or relocate those.
My Robodrill has absolute encoders on it. It never needs to home unless the batteries die.

thanks,
Donny

[ger21]

Sounds similar to homing to an index. Usually, you home to a regular switch first, and then home again to the index. Some Mach3 controllers have this functionality built in. I think CS Labs is one that does.

[whiteriver]

CS labs. Never heard of them. Might need to look them up. I will need to have a index pulse on my spindle so I can home it and then use it to rotate the tool holder. Still not sure how I am going to accomplish that.

Donny

[mikecolee]

Hi Donny,

I used CS Labs motion control H/W on a retrofit and I can conform the precision home works well. You'll need good quality home switches. The control finds the switch, can be NO or NC, then it backs up the axis to within +/-5 pluses on the encoder to achieve precision. I am using 500 line encoders and the precision on my machine is +/- .001 which is quite likely more a function of backlash than the encoders.

I went with CS Labs CSMIO-IP/A because I was keeping the servos and amps and they needed +/-10vdc control inputs. If your going step/dir then you have more choices... Take a look at Kflop... If you care about your machine and tooling I highly recommend dedicated motion control hardware with Mach 3/4.

Mike

[whiteriver]

Mike,
Thanks for the information. My encoders are 2500 line. My AC Servo drives will take +/- 10v or Step and Direction. I will be using a Smooth Stepper for now since I had one laying around. It only sends step and direction. I have some good quality switches and will install them for the homes.

How do you set up Mach3 to run a motor as a spindle, stop, then home and the index?

I might have to order a CS board to play with. I do like what I read about it so far. I design and build motion control systems for my day job and sometimes I use Mach 3. The CS boards might be a good fit for the ones that use Mach 3.

Donny

[ger21]

How do you set up Mach3 to run a motor as a spindle, stop, then home and the index?

You need a Mach3 motion controller that supports homing to an Index. It would be configured in the plugin settings.

[mactec54]

That's kinda what I thought. Since it say moves 1/4" every rev it would never know where exactly it is. It could take 20 revs to get to home or take 1. I'll just put new switches on there or relocate those.
My Robodrill has absolute encoders on it. It never needs to home unless the batteries die.

thanks,
Donny

You just use the limit switches, that is all that is needed for homing, you can remove the proximity sensors, they are not going to make it anymore accurate for homing, you can change the limit switches for proximity switches

[mikecolee]

As per Gerry, the setup interface for indexed homing is in the CS-Labs plugin. Two other nice things I'll mention about CS-Labs... The auto PID tuning worked really well on my retro-fit and it's also a feature of the plugin. Lastly, the prices are in euros so currently we are getting a good exchange rate with the strong dollar.

Mike

[mactec54]

Hi Donny,

I used CS Labs motion control H/W on a retrofit and I can conform the precision home works well. You'll need good quality home switches. The control finds the switch, can be NO or NC, then it backs up the axis to within +/-5 pluses on the encoder to achieve precision. I am using 500 line encoders and the precision on my machine is +/- .001 which is quite likely more a function of backlash than the encoders.

I went with CS Labs CSMIO-IP/A because I was keeping the servos and amps and they needed +/-10vdc control inputs. If your going step/dir then you have more choices... Take a look at Kflop... If you care about your machine and tooling I highly recommend dedicated motion control hardware with Mach 3/4.

Mike

Do you not use or have the index pulse ( Z Pulse ) for the Homing, this is the norm to get an accurate position the same each time

With a 500 count Encoder you are not serious about any kind of precision, 16Bit to 24Bit is the standard for anything serious with machine control/accuracy 16Bit is 65,384 CPR, Anything Below a 14Bit Encoder you are wasting your time, if you are looking for good machine performance and accuracy

[steryd]

Did You succeeded with this retrofit?
Have You used the additional proximity switches that watch leadscrews turning?