[adprinter]

I have a problem, which I THINK can be addressed electronically. However, I am unsure of the method (or correct device) needed to get there from here.

The Problem: My Porter Cable Router works it's little heart out, carving Oak pieces for me for days on end. And it wears out the motor brushes with some frequency. Most of my carvings are 3D, which take HOURS to cut- therefore I leave the machine running unattended at times. And it seems that it is always during these times, that the motor brushes wear out on the Router. When I return to check on the machine's progress, and find it still moving the Router along the tool path which now has a broken bit (since the motor brushes wore down enough to stop the Router motor from turning).

The Solution: ??? I know that there should be a way of installing some type of motion detector (perhaps an encoder of some type) on the Router chuck, which would trigger a Fault in Mach3 and stop the program's execution until the Reset button is clicked. This would be a tool-saver! For if the Router motor stops turning, and Mach continues to run, it invariably plunges the tool into the work piece, which results in a broken bit Each and EVERY TIME the motor brushes fail (since the Router motor stops turning)!

Does anyone have a useful solution for this problem? I have thought about using an encoder, to provide feedback to Mach3- but the problem is Where to mount one? A Router motor is not like a Spindle, with an external shaft on top (which could be used to mount an encoder). Therefore, it must be some type of device which could be mounted onto the chuck collar. Ideas? Anyone?
All help would be appreciated!

[Al_The_Man]

Here
http://www.cnczone.com/forums/diy-cn...ter_speed.html
Al.

[Lake Cruiser]

I agree with AL. Very happy with mine.

[adprinter]

I agree with AL. Very happy with mine.

So, the Super PID sends a signal which STOPS MACH3 PROGRAM EXECUTION when the motor brushes wear out on the Router motor (which causes the Router motor to STOP TURNING)? My question for you is: How does the Super PID sense this condition?

[jm82792]

SuperPid attempts to keep the speed by throttling the router. It keeps your router from burning brushes as fast if you are using it below(I'm guessing right?) speed by dynamically adjusting to your load(keeping RPMs locked to your set speed instead of it going faster when it's not under load).
I can't recall what they are called but I was eying a package that consisted of an IR sensor and IR led plus a few other components that are basically the same thing SuperPid uses. I was planing on creating my own hack of Superpid with an arduino and DIY SCR speed controller.

You need to see what information superpid can send to your computer, if it sends actual RPMs then I'm guessing your set with a script.

[adprinter]

Here
http://www.cnczone.com/forums/diy-cn...ter_speed.html
Al.

Al,
I owe you an apology it seems, I thought that I had previously researched the Super PID device (some time ago). However, after downloading the PDF and reading about how the device works, it appears that it's just what I need. As soon as I am able to get the funds together, I will probably be ordering one! Thanks!

[ger21]

Why not just change your brushes at regular intervals, whether they need to be changed or not. They're cheap.

[Drools]

Will the S-PID actually stop the machine if the spindle RPM is 0? I guess I should RTFM as I did not know it would do this. This is a bonus if it indeed does this.
Since the sensor setup is so simple, one could imagine a sensor on each axis lead screw which also monitor the axis movement. I know this is a servo encoder area but I have seen quite a few stepper users ask this question. Roman...

[Al_The_Man]

Will the S-PID actually stop the machine if the spindle RPM is 0? I guess I should RTFM as I did not know it would do this. This is a bonus if it indeed does this.
.

There is a1/rev Tach pulse output that could be utilized to do this.
Al.

[RomanLini]

Thanks for mentioning the SuperPID guys.

To Adprinter- from memory I think sliding surface wear (ie brushes) is at the cube of velocity so if you run the router at a slower RPM you will get greatly reduced brush wear. For example dropping the RPM from 25000 to 12500 (half) will give 8 times less brush wear.

And as Al_the_man said the "TACH" output pulse from the SuperpID can be connected back to Mach3, so Mach3 can supervise and shut down the machine if you get a spindle fail.

[Drools]

Thanks Al, I was just searching through the manual and on page 27 it mentions the "Tach Output". I'm thinking this output would have to be sent to Mach3 (for Mach3 users) and then configured in software to stop the router when the Tach Output is 0. I wonder if a ranged value can be used... Now I have to read the Mach3 manual.

[ger21]

You'll need to use the macropump or brains in Mach3 to do this. It's not a standard built in feature.

[adprinter]

You'll need to use the macropump or brains in Mach3 to do this. It's not a standard built in feature.

Do you have any particular info on How To use the macropump, or brains in Mach3 to set up something like this? I have only used Mach3 in it's basic form- I haven't used any special macros, scripts, etc. to do anything special. So I am somewhat ignorant in this area. When I first built my machine, I struggled for almost 2 weeks in just getting the limit switches properly wired. I am not an electronics expert, but have been able to figure a few things out by asking questions on the Mach support group, and this forum. I have the Mach3 manual, perhaps if you could just point me to the correct page which discusses this, I could begin to "figure it out". THANKS!

[ger21]

perhaps if you could just point me to the correct page which discusses this, I could begin to "figure it out".

Unfortunately, there is no page that discusses this.

The macropump is a facility to repeatedly run a macro (10 times per second) so that you can use it to monitor things (like spindle stopping). Brains can also be used for monitoring, but run much faster, and use less overhead.

So, you either need to write a macro and use the macropump, or create a Brain to do it.