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Tool changer motor overheating
« on: April 19, 2015, 02:01:38 AM »
Hi there,


I have a Syil AEX250 CNC lathe that I have been running for a couple of years now with only
minor, easily fixed, issues.

Running Mach3 R3.043.066, licensed. The computer CPU is 3.40Ghz, with 2Gb ram.

Yesterday I installed an Ethernet Smooth Stepper, and jumped through all the hoops to get that
up and running, I'm very happy with it so far.

1 problem I have not been able to fix is the tool changer motor now overheats. Yesterday, when I
discovered the problem, I measured the motor case at 98 degrees C. Until yesterday the motor never
even got warm.

Today I was able to listen to the motor with a probe stethoscope, I found that there was no noise from
the motor until I made the first tool change, after that the motor continued to hum and began to heat up.

I went into "ports & Pins", "Input Signals" and turned off Active Low on Input #1, which is set to port 1 pin 15.
When this was applied the motor stopped humming. Turning on Active Low and doing another tool change
caused the motor to continue to hum after the tool change was complete.

Jeff, from Soigeneris, has suggested that the motor is not being turned off after the rotation and lock down
of the tool post. My testing above would seem to confirm this.

I'm hoping someone can point me in the right direction to solve this problem. If posting any files will help please
let me know which ones you need.


Best regards
Mark

Offline Hood

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Re: Tool changer motor overheating
« Reply #1 on: April 20, 2015, 04:32:03 PM »
Normally stepper drives are permanently enabled but some  have a feature that can reduce the current when stationary for a period, that may not be working or maybe a dip switch has been altered.
Hood
Re: Tool changer motor overheating
« Reply #2 on: April 21, 2015, 05:27:51 AM »
Hi Hood,

Thanks for you thoughts.

It looks like the motor is DC , and drives forward, raising the tool post and rotating it past a pawl, The
motor then reverses, catches the pawl, and locks the tool post down.

I know I didn't go anywhere near any dip switches when I installed the smooth stepper.

I suspect these lines in the M6Start macro are being missed somehow...

deactivatesignal(output5)
deactivatesignal(output2)

I have attached the macro file if you wanna have a look. The bit that looks like corruption was in the file when
I received it, and had worked file while using the parallel port. Removing it didn't fix the issue.


Best regards
Mark

P.S. I had to add the "_Mark", as I got a  message saying the file name already existed

Offline stirling

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Re: Tool changer motor overheating
« Reply #3 on: April 21, 2015, 09:48:51 AM »
Where did you get that macro? it's bloody awful...

That said to even attempt to find the problem can you explain how your toolchanger is supposed to work and exactly what functions outputs 2, 3, 4 and 5 and input 1 are supposed to do.
Re: Tool changer motor overheating
« Reply #4 on: April 22, 2015, 05:45:22 AM »
Hi Sterling,

Thanks for taking a look.

The macro was supplied by Syil, the manufacturer, so far their suggestions
have been to remove the Smoothstepper, or talk to Jeff at Soigeneris. I've
written to Jeff and he suggested removing the part that looks like corruption.
This didn't work.

Here's my (limited) understanding of the way the macro works.

Outputs 3 and 4 are used to determine the location of each tool on the tool changer.

Case 1 off-off
Case 2 on-off
Case 3 off-on
Case 4 on-on

I have to assume output 2 runs the tool changer motor forward. This raised the tool post,
then rotates it on a ratchet to just past the selected tool position. Output 5 reverses
the motor, rotating the tool post back against a pawl, then the tool post lowers to it's
locked position.

Outputs 5 and 2 are then supposed to turn off.

My testing seems to indicate the motor is continuing to run. While it doesn't have enough
power to break anything, it is generating a large amount of heat.

As I suggested earlier, it looks like the deactivatesignal(output5)and deactivatesignal(output2)
lines are being missed.

Jeff also suggested that noise may be causing some problems. I tried a few small values in the
Smoothstepper config, without success. I then tried 100, a value I'm led to believe is way more
than should be required for the Smoothstepper, also without success.

If you have any suggestions I'm willing to try just about anything.

Again, thanks for your time.


Best regards
Mark

Offline stirling

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Re: Tool changer motor overheating
« Reply #5 on: April 22, 2015, 06:29:50 AM »
Hi Mark

Apart from your motor overheating, does the toolchange actually work as intended?

Re: Tool changer motor overheating
« Reply #6 on: April 22, 2015, 07:42:34 AM »
Hi Sterling,

Yes, it does. I had run a part as a test of the Smoothstepper and only noticed the hot motor when
I went to brush some swarf away, after the part had run.

I've done a bit more research and I'm going to play with the G4 pauses to see if they need tweaking,
that will have to wait until after work tomorrow though.

Regards
Mark

Offline stirling

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Re: Tool changer motor overheating
« Reply #7 on: April 22, 2015, 08:15:28 AM »
It's curious because from what you've said my first thought would be that the input is not being triggered. However that can't be true because that would hang the macro and so your toolchange would never complete or at least Mach would not continue after the toolchange.

Without knowing exactly how the toolchanger works and exactly what outputs 2 and 5 do it's hard to offer advice.

You may be onto something with the delays. One thing I'd do though is get rid of those ridiculous G4 dwells. Use sleep instead.

E.g. replace the likes of

code "G4 P0.1"
While IsMoving()
Wend

with

sleep 100

(actually there's a thought - you don't have "G4 Dwells in ms" ticked in general config do you?)

When I said the macro was bad, here's some things you may want to change.

1) Check the requested tool number is valid and error handle if not
2) Apply a timeout with error handling to the wait for INPUT1
3) Use the symbolic constant INPUT1 instead of the "magic number" 18
3) Get rid of those G4 dwells and use sleep as I've described

Anyway - just some thoughts.

Offline BR549

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Re: Tool changer motor overheating
« Reply #8 on: April 22, 2015, 11:44:57 AM »
You need to test the inputs to the DC motor to verify IF the motor is actually turning off. Sounds like it is NOT and will overheat the motor. Simply test. It MAY be that the Polarity of the signal is backwards in the SS causing the motor to stay ON.

Just a thought, (;-) TP

Offline stirling

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Re: Tool changer motor overheating
« Reply #9 on: April 22, 2015, 01:19:04 PM »
Yeah Terry, I reckon the motor is still being powered but the weird thing is that if he turns INPUT1 off manually, the motor stops over heating until the next tool change. So turning INPUT1 off appears to cut the current to the motor.

That would imply that INPUT1 is there to turn the motor off but it's NOT turning off in the macro.

However, as I've said, if that were the case, then the macro would hang - but it appears that it isn't.

Doesn't add up.