Can I create lead ins?

My table is a plasma machine with an trocen awc controller and I’m wondering if I can do lead ins with this software. Lightburn 1.4.00

Yes. But from others’ experience using LightBurn for plasma cutting there may be some shortcomings that make it nonideal currently for that use.

More about lead-in here:
Line Mode - LightBurn Software Documentation

I ran my grbl v1.1i plasma table with modified LB gcode, including LB lead-ins. I modified the generated gcode to handle per cut torch touch-offs since I have a THC. Given I was doing that, I also had my code insert the pierce delay, as well as the end of cut torch-off delay before retracting the torch in prep for moving to next cut. That all worked fine for small jobs of a few shapes and pierces, but when my projects got larger (> 5 pierces), then I found LB was overriding my choice of lead-in position and sometimes cut direction. That got rather tedious to maintain iterate designs, it could affect all shapes even though I changed just one shape or shape position. So now I use LB for all 2D designs, and SheetCAM for the plasma toolpath. SVG is exported from LB, then import to SC. Its a 10 second workflow. Other SC benefits include the visual of the kerf and thus bridging between shapes, disabling the THC on sharp corners and small circles and arcs, and SC does an excellent job of lead-in placement, including retention across multiple import iterations when I sometimes manually modify the start points.

Search on my handle @bLouChip as most of my postings here are in reference to plasma process, but I do use LB for my laser too, and now routing, same machine.

You are welcome to reach out to me if you have questions.

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This is very helpful thanks. Any recommendations for a THC? I’d like to find one I can add on.

I use a Proma Compact THC SD. It does a fine job, but its not without some quirks which I’ll explain later. Recommending it comes with “it depends”, YES if you are building a multi-process CNC (milling, laser, plasma). In my case, the unit came with my CNC kit, so I used it and made it work rather than look for other THC solutions for a multi-process CNC.

As an alternative, if you are building a plasma dedicated CNC, I would seriously consider another product by Proma, MyPlasm CNC System. There are good videos at the website which instruct you in building a plasma CNC. I suspect this product has a THC Z Anti-Dive built-in, which I have found to be critical in plasma CNC. If you desired to expand your CNC into multi-process cutting, the system professes to have function to handle milling process, but I doubt that laser process would be supported as I don’t see a PWM output signal from the unit (it would also need $30,31,32 grbl config registers). In the MyPlasm CNC case, you could use LB as your 2D design sw, export DXF, import to MyPlasm CNC for toolpath and CNC control. Eagle Plasma CNC offers this and other Proma products.

Re. the quirks of Proma THC SD-- It has a nuisance bug when configured to drive Z with ‘-1’ direction, the fix was to force it in ‘+1’ direction by reversing the wired rotation of the Z motor and informing grbl of the reverse direction. It also does not account for THC Z Anti-Dive, the fix was to build a digital circuit to disable the THC Z control when the XY feedrate fell below 90% of the programmed value, accomplished by monitoring the PWM signal. THC Z dive occurs when XY feedrate slows during sharp cornering and on small circles, where the THC sees a spike in arc voltage and reacts to drive the torch lower. This has two bad effects; first the cutting gap is in error (1.5mm is norm gap), second the error can go uncorrected by the THC if normal feedrate is not regained for a long enough period before the cut ends, and this causes an accumulation of Z machine position error which can eventually hit a Z axis limit in over 20+ pierces/cuts.

You are welcome to DM me for more details or questions.

btw, I’d like to clarify my earlier post(s) explaining why I don’t use LB for plasma toolpath, which includes LB lead-ins. LB does a fine job in regards to lead-ins, outs, toolpath start point, and direction as it concerns laser process, which is what it is designed for. I was pushing the limits in trying to apply those features of LB to plasma process, and in doing so I discovered using SheetCAM for the plasma toolpath was much better in my case. I have never meant to disparage LB on these functions, and I probably should have been clearer about that in prior postings, sorry to have left anyone thinking otherwise. I like to consider myself the biggest fan of LB :+1:

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