[kstrauss]

The Tormach SmartCool appears to be a great tool but, as a mostly hobbyist, I can't justify its cost. Has anyone investigated reverse engineering it?.

[rowbare]

Ken,

Check out this thread: https://www.cnczone.com/forums/open-...t-nozzles.html

bob

[kstrauss]

That thread was my original inspiration! BTW my Leonardo now convinces PP that it is a SmartCool and it understands coolant on/off, alt-U, alt-D, etc.

[rdsi]

While creating some digital output lines using the extra port already available on the MESA card this thought passed through my mind also. So I dug deeper into this idea.

First, I don't think this is a good marketing idea. There just is not enough volume to justify it, hence the high cost that Tormach charges. If you're using your machine in a business venture & this product will really improve your bottom line cost is not going to be a problem.

For the rest of us, yeah, it could be implemented pretty easily. It's really just a coding issue and the hardware is off-the-shelf stuff with a little fabrication, but hey, that's what we do ...

So all we need is a stepper motor hanging onto the spindle with an adapter to hold our coolant/mist line - nothing to that. So after nosing around a bit in PP my first thought was to use the available I/O on the MESA card to drive the stepper motor. There are several step generators already programmed in the FPGA that can be used for this purpose. With some modifications to PP this could done pretty easily since the framework is already there.

Another approach is to use a separate micro-controller such as Teensy or ItsBitsy to emulate the product that Tormach offers. PP would not have to be modified but one would have to code the micro to emulate the Tormach unit. Depending on your coding skills this could be more difficult than modifying PP.

I have several IDE/debuggers that I use for developing micros on other projects & my first thought is that it would be easier to modify PP & use the MESA I/O already available. That being said you just really don't know until you get into it.

Anyway, it's on my mind too.

[kstrauss]

All good thoughts and I considered most before starting anything. I'll try to explain my decision process:
Yes, it is a small volume accessory so the price has to be high to recoup development costs. I have no intentions of selling a substitute.

If I were running a production shop I wouldn't hesitate to purchase a turnkey unit. I see this as mainly a learning exercise between paying work and a way to keep my aging brain working.

My coding skills with micros is far better than with Linux so I wanted to minimize PP changes. Plus, it is an ongoing pain to retrofit changes after each PP release.

Using a stepper has many advantages but requires some sort of homing mechanism to position it on startup. I didn't want to require a custom PCB to combine the micro and stepper driver for a one-off. With that in mind I'm using a R/C servo. That means the only electronics is the micro, a relay board to control the air blast pneumatic valve and a wall-wart power supply.

I'm still fighting to get the aiming exactly right. However, aiming is sorta working, air on/off, timed air, wiggle mode and the keyboard shortcuts are all working. Total code is less than 300 lines including lots of comments and debug code. The electronics cost about $15 plus $25 for the servo. Now to complete the mechanics and box things!

[rdsi]

My coding skills with micros is far better than with Linux so I wanted to minimize PP changes.

Are you plugged into the USB port & parsing the SmartCool commands to run your probe?

[jwatte]

all we need is a stepper motor hanging onto the spindle

The Schnozz/SmartCool uses a Robotis AX-12A servo motor, which has an absolute position sensor. It talks single-duplex TTL serial protocol, and costs about $45. It's a reasonable choice for this kind of application. (Robotis has since released an even cheaper and mechanically smaller version called the XL-320, it's about $25.)