Ecocam Tangential Knife Post for Vcarve Pro

So I have installed an Ecocam EOT-3 tangential knife to my machine. I have it working in Mach4 without any issues thus far.

I am now trying to figure out how to use the A-axis to rotate the tangential knife in the post. Has anyone done this before or have any information that can point me in the right direction. Or alternative software to make life easier.

There is a “tangential knife” screenset in Mach 4. I’ll be honest I have never used it. I believe it is setup to work with these style knives. It might take regular G Code and issue whatever commands you’d need to activate and turn that knife.

Something that I have used is the “dragknife” toolpathing in VCarve. This allows you to use a tangential knife that has a plate that’s offset from the spindle centerline.

These types of knives just dangle like a rudder on a boat so no commands are issued to turn them, which is I believe what that Mach 4 screen can do.

If you did need those commands issued in a Vectric post it might be doable, but the approach will take some research.

You might have to make a “gadget” in Vcarve to do what you want… again I’m only guessing here.

/Edit - I just looked up that Ecocam thing and it’s not a simple dragknife, so my original scribblings likely don’t apply - sorry. The ecocam is a whole lot more complicated! Does the manufacturer not have some support for popular platforms like Vectric? I see they do have a gcode example on their site

Here are three options I haven’t tested.

The first option is to figure out the built-in tangential support in Mach4. Here are a YouTube video and the documentation. It involves loading a particular screenset that is shipped with Mach4 and setting parameters appropriate for your knife. Then I believe you can run G-code with X&Y moves only, and Mach4 will handle the angle commands and the raising/lowering. In Vectric, I think you could just generate toolpaths with the tool diameter set to your knife width. I don’t know whether Mach4 ignores Z commands with the tangential screenset.

The second option is to write a post-processor. Here is an Autodesk forum post about a Fusion tangential knife post-processor. The processor itself lives here on Github. Another post example is the SheetCam tangential knife post-processor in Masso’s list of SheetCam post-processors. These show you the parameters, raising/lowering, and angle calculations needed for tangential cutting. You would need to adapt them to VCarve’s post-processor format.

The third option is to take G-code and post-process it directly. For example, here is a Python processing script for a drag knife which takes XY moves and generates new G-code with arc offsets and raising/lowering added. For a tangential knife, you would need to remove the drag knife offset and arcs, add the angle as an A command, and change the raising/lowering parameters and logic.

It took me about 3 months to get it working after figuring out how to wire it to the driver. I made a seperate box with two switches and the wires and variable power supply for the oscillator that feed the EOT. You’ll need the “tangential” screen set for Mach4 and set the A axis to the EOT. There is a tab for the Tangential which sets some of the parameters that tell Mach4 how to follow the path by turning the knife.
If it is set up correctly, you should be able jog the A axis to turn the EOT.

what did you use for the steps per degree. I seem to be struggling with this for some reason. I’m either short or past when doing 360 degrees.

Shouldn’t be too hard to find with a search. I don’t know what scale you’re working with, but if 20 steps/unit is too low, and 22 is too high, try 21. If that’s too high, try 20.5. Keep trying the middle of the remaining range. Then try with a 720 or 1080 revolution so you can dial it in better.

I’ll get back to you on that. My machine is used for our sign business.
When I go in on Monday I’ll take a look.

Thank you very much I greatly appreciate the help!

Last question. Did you add a limit switch so that it homes on the A-axis?

If you wired it correctly, it is built into the unit already.

My issue now is the a axis keeps tripping motor 0++, I looked through the ESS and homing and couldn’t get past this issue. It will spin and tigger a limit switch. Did you run into this?

What version of Mach are you using, if I may ask?

Thank you for the help thus far.

Is motor “0” set to the A Axis?

No in my case it is Motor “4” as intended for the rotary axis.

Will each axis home independently or is it failing on “home all”. Which axis is motor “0”?

I found that the homing of the EOT3 works better if you randomly jog it to get it off “0” and then home it. I wrote a routine for my machine that homes all and then sets the spindle to 0,0 on my machine and another one that homes all and sets the EOT3 to 1,1 which is where we start all of our cuts.
You would have to modify it for your machine motor assignments and size.

So in my case Motor “0” is the X-axis. I can get machine to home if the a-axis is not homed at the same time.

Once the a-axis is homed if I manually rotate it wit will trip. I logged what was happening and this is what I got.

Signal id 1127, (Jog Enabled), changed from LOW to HIGH.
Signal id 1172, (Machine Idle), changed from LOW to HIGH.
Signal id 1120, (Machine Enabled), changed from HIGH to LOW.
***ESS: 1 - Limit Switch trigger on Motor Limit 0++
ESS: Limit Switch triggered on Motor Limit 0++
####### ESS Reset Velocity A
####### ESS Reset Velocity A

The limit switches are configured in the Mach4 menu Configure > Plugins > ESS > Input Signals. It sounds like your A axis sensor is configured as a limit switch, and it needs to be removed. If your A axis sensor is triggering a limit switch on a different motor, then something might be wired incorrectly or the input signal in Mach4 is configured incorrectly.

Sorry for the delayed response. You were correct removing the limit switch stopped that issue. I got it working with well now which is great! @Alevitt53 is correct that proper setup you should change the motor setup. I spoke to avid as well and they confirmed changing the motor setup in the ESS.

Thank you everyone for your help.

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