Gear ranges

[martyscncgarage]

Marty,

Nope, I have a 2 HP 3 phase motor with a 2HP VFD. So I'm good with just using three of the gear ranges as that is about all I use now! I see no reason to complicate the issue now that I have read the above post. I could still use the spindle manually if there was something that did not fit in the 3 ranges.

IE: Big diameter part needing slow RPM for outer edge turning. I have my VFD set for constant torque so maybe not a problem?

Common sense I guess, I just had not thought it through and I was still thinking in terms of how Mach 3 handled the gears.

If you can live with three ranges then that is built into the Wizard. Roll with that for awhile and see how it works out for you.

Marty

[Muzzer]

Hi Scott

Sorry, I should explain. I have 2 electrically selectable ranges. If the spindle speed needs to be 1000rpm or higher, it needs to select the high range. Below that it needs to be the low range. So the controls would select the correct output status (high solenoid or low solenoid) before enabling the spindle. This could be done with one output if I'm careful. It wouldn't matter how the machine started up, although defaulting to high range really wouldn't be a problem.

There are status switches on the selector mechanism to show which range is currently engaged but I could live without that if it selected the correct ratio anyway.

The solution proposed previously would require the operator to manually select the correct range and the system to use the status inputs to confirm. But that seems sort of backwards on a CNC system. It also uses up 2 precious inputs.

Sounds as if I should read up on M codes to see if they would be a solution. I was wondering if you had encountered this situation before and had a simple solution.

Thanks

Murray

[Muzzer]

Hi Keith

I am hoping to automatically (pneumatic solenoid) select the correct gear range based on the required spindle speed. At or above 1000rpm it should be high range, below 1000rpm it should be the next lower ratio (I have only 2). I think I should be able to create a modified macro to achieve what I need. On the face of it, it should be a relatively simple test to determine which range is required(!), then to output the correct solenoid signal, although I'm a bit confused that the spindle speed seems to be held in several variables and am not sure which I would want to check. I don't think it is critical to feed back the actual gear position on my system.

What would you recommend? My thoughts were to modify the M3 (Spindle CW) and M4 (Spindle CCW) macros to compare the current S demand against the threshold, set the appropriate gear range variable and also set the solenoid output - and then (after a delay) start the spindle as before. However, without knowing what is already going on, I can't be certain this will work. There are gear ratio macros M41-43 available but are they intended to tell CNC12 what gear you have selected manually or are they intended to drive a gear selector mechanism?

I wonder if you could give me a pointer here. Thanks!

[martyscncgarage]

Hi Keith

I am hoping to automatically (pneumatic solenoid) select the correct gear range based on the required spindle speed. At or above 1000rpm it should be high range, below 1000rpm it should be the next lower ratio (I have only 2). I think I should be able to create a modified macro to achieve what I need. On the face of it, it should be a relatively simple test to determine which range is required(!), then to output the correct solenoid signal, although I'm a bit confused that the spindle speed seems to be held in several variables and am not sure which I would want to check. I don't think it is critical to feed back the actual gear position on my system.

What would you recommend? My thoughts were to modify the M3 (Spindle CW) and M4 (Spindle CCW) macros to compare the current S demand against the threshold, set the appropriate gear range variable and also set the solenoid output - and then (after a delay) start the spindle as before. However, without knowing what is already going on, I can't be certain this will work. There are gear ratio macros M41-43 available but are they intended to tell CNC12 what gear you have selected manually or are they intended to drive a gear selector mechanism?

I wonder if you could give me a pointer here. Thanks!

First, it would have been better if you started your own thread. Your situation is somewhat different and unique than Dave_C
In my mind, it seems you need a bit of PLC programming time.
Repost your question in a new thread. A picture or two would be helpful as well
Marty