tangential knife along multiple layer height

Hello, I'm trying to find out if it's possible to use tangential knife for with multiple z axis layer heights overlapping? Does anyone know if this is possible or what modifications might need to be made?
Any help is greatly appreciated!

Hi Jamie,

Tangential knife is a nice solution. I can advise to use the sheetcam tangential knife module :
sheetcam.com/Register/purchase
Then look at the drag knife module.

and use a special tool like this :
tangential module

This tool is like a saw. It cut's up and down with a separate dc motor, and it rotates your defined knife axis with a stepper motor without loopback.
The tool has also a separate home sensor, so your knife can be at position when machine start's up and your home
switches are connected. You don't have to specify a rotary axis in linuxcnc. It can be adjusted as normal axis.
For the tool you need to order a separate dc power supply. Then you are done.

It really work's. In the past i did modification's to the sheetcam's tangential postprocessor, but in the end i was satisfied.
If you need the post processor, i can send it to you.
Overlapping different heights is not difficult to do in sheetcam.

Thank you! That's some really good information. I've tested the tangential macro in mach3 and it works for my application but I would rather use Linuxcnc. I wasn't initially considering using sheetcam because I thought it only worked with vector and dxf. I'm using this for a welding application where the welder wire feed remain ahead of the direction of the weld pool. As far as I know there is no post processor for hardfacing with tangential C axis on potentially hundreds of layers.

Hi Jamie,

DTPS is a online and offline 6 axis welding software application that can help you. You can contact : www.valkwelding.com
It cost's a few 1000 euro. But it's a really good software.

In linuxcnc it's also possible to weld in tangential methode. Linux is has even more capabilities then robotic software at this moment.
When you have a drawing of wat your goal is, i can look at it.

A good description of the proces is also good. It must be clear in all axis viewports, so that is why i ask a drawing of the proces.
We have a option to write code in real time to get some things done in every axis way. Don't say you weld with a Fronius.

I also want to implement the difference in your application : mach3 to Linuxcnc
I can say mach3 can't be core modified. Linuxcnc has unlimited core modification's. It is the future.
Hold on. Don't forget.

I am using a profusion dual Arc 80 micro plasma arc welder using DMM servos on a 7i77 & 5i25 for real-time control. I'm not sure if that software you mentioned will play nice with what I'm using but it's worth checking out. To put things simply I'm trying to find out if the linuxcnc tangential knife macro will following XY for all feed moves but not Rapids regardless if the Z axis is at a different position Heights?

Hi Jamie,

To imagine your plasma arc welding process i need a drawing or a clear picture, the i can see what you want to do in movement's
with linuxcnc.

To expand your expetation's:

In x we can do offset's on a input sensor or by calculating improved path's
In y and z and so on we can do that.

Tangential is difficulter to calculate in real time. Will i go back or will i go a little bit forward with my cladding torch?
So if your solution can be without tangential a-axis rotation it's always better, if possible.

Yes, I can see how it would be hard for the A axis to remain synchronized with the xy. I'm not exactly sure what you mean by G-Code filter. I'm a bit familiar with people using spreadsheet to edit the g code but my trigonometry is not that good and I haven't found anything that will allow me to add a specific line beneath other designated G Codes automatically. I read on another forum of someone using a method called "postpost" that sounds similar to what you're describing. I'm honestly surprised that there isn't a tangential post processor that isn't just 2.5D