lead ins and outs

[M & N Steel CNC]

What do you set the length of your lead in / lead out to be?

[WyoGreen]

I find the lead in/out needs to be set to fit the space you have. Small cut outs need a shorter lead in/out, larger cutouts can take a longer lead in/out. Naturally, a short lead in/out may put a ding in the side of the cut, but I figure thats still better than none at all. I have set my length anywhere from .015 to .25, depending on the drawing. Often times I will make different layers so I can use different lead in/out lengths and or shapes.

Hope that helps, Steve

[M & N Steel CNC]

Thanks Steve appreciate your response.

[beefy]

It will vary depending on how thick the steel you are cutting is. Thin material with a small nozzle is going to have a much smaller pierce hole than 3/4" thick plate. In addition, the pierce point in thick plate may end up with a nice blob of slag there.

I'd play with some scrap pieces of different thicknesses /materials. The cut wants to have stabalised by the time it gets to the actual part outline. Aim for the shortest lead in that give you a nice cut at the entry point. Of course when you have a very narrow internal cut you may not have the luxury of you minimum distance leadin length so just find the widest point, put your start point there, and make the leading length so that the pierce point is in the middle.

Cutting 3mm steel with arc leadins, I found I was getting little pointy bits on the edge where the the arcs cross. Sheetcam has a great overburn feature so the cut can continue past the leadin point before starting the leadout. That burns away the pointy bit.

Keith.

[M & N Steel CNC]

Thanks for all your help

[rikduk]

Same here...
16g to 1/8, around 0.2 lead
1/4 plate, 0.28 lead
1"plate, 0.75 lead
Also, on 1/8 thick stainless and up, try slowing down to 70% the last 0.125" before lead-out,
so your parts fall easier.

[imsly0]

How do I get my peirce away from the line, when I am trying to lead in or out I change the lead in and out but it still peirce to close to the line?

[muzza]

Set your pierce to perpendicular or arc and enter the length.
Murray

[acourtjester]

I'm not sure lead in/out are for lines you cannot use offsets for open lines.
This will also extend the line and may carry over into other cuts by accident.
working with pierce height and delay time you can reduce the dimple at the start.
Here is some info about pierce delays that may help.
http://forum.sheetcam.com/viewtopic.php ... fdf673d4c8