Blasted divots....

[sr guy]

I am having the same issue. I have the ethercut, the divot on the back is frustrating if you guys find anything out please continue posting. Thanks for all the info.

[motoguy]

I am having the same issue. I have the ethercut, the divot on the back is frustrating if you guys find anything out please continue posting. Thanks for all the info.

Same as this guy.

[sr guy]

I got mine fixed. I called dan at ldr and he wrote a post script for sheetcam and told me how to set some things up in mach 3. So now I just made code snipets for different thicknesses. I know this doesn't help a lot. I just don't want to give bad info for someone else's machine.

[davek0974]

But what action does the post add?

[exapprentice]

Hi sr guy

How about some more details
you said

"he wrote a post script for sheetcam and told me how to set some things up in mach 3. So now I just made code snipets for different thicknesses"

You just cant leave us hanging and not give some more details of what he told you etc
Out of pure curiosity I would love to know more maybe Dan from LDR can explain what he did, you know we are a curious bench and we all have the thirst for more knowledge

[tnbndr]

maybe Dan from LDR can explain what he did

Especially since I have an LDR table, but anyone using SheetCam and Mach 3 should be able to use the same concepts.
What kind of code snippets help eliminate the divot?

[acourtjester]

Maybe the FBI can demand the secret code then we all can hack in

[sr guy]

LOL ok I will see what I can do here.
Attached is a post processor for early torch off. There are some things
you need to do before you use it:
1. In mach3 click plugin control then general config
looking at the attached pic, st the m10px and m11px to gate spindle output
also set the dwell to 0

2. in sheetcam, load post attached
create a code snippet, name it early torch off and code should be M10P1
now create a rule set, with only one rule, before end run the above code
snippet.

[sr guy]

A couple of days later he sent me this.
1. close all programs on computer
2. turn control box off
3. open c:\mach3\plugins folder
4. delete the ess****.dll file
5. Copy attached ess***.dll file in to the c:\mach3\plugins folder
6. Turn control box on
7. start mach3
8. click plugin control from the pull down bar
9. click ess config
10. refering to picture attached, set your config to same as items circled
in picture.
11. close config
12. close mach3
13. in sheetcam you will need to create a code snippet (this is done by
clicking the "g" in the tools section:
name : Torch early off
code : M10p1
14. Now create a path rule. Before end "x" distance feedrate 100% start
code use your code snippit you just created.
15. Now when you set up operations you will need to pick that rule.

[sr guy]

Ok with all that being said I don't want to step on dans toes and give his files away. Not that anyone is asking for them. So to answer your question I don't know what he changed in the post script. I imagine that it had to do with allowing or telling sheetcam that it was ok to shut off the plasma while continuing to move. My previous setting for m10 and m11 were at 20. Hope this helps guys.

Dennis to answer your question. When creating a snippet or rule it will ask the questions and if everything is correct you could us M10p1 that is the torch off code. I tried this before talking to Dan and it caused a delay and didn't work.

[motoguy]

I would be very interested in knowing what was done to get the "torch end early" to work. Does LDR use CandCNC electronics?

[comeoutswingin]

I'm thinking I'm going to have to make some phone calls to LDR and get this set up on mine as I am getting a gnarly gouge at the end of my cuts, often times bad enough to ruin the part.

[dhelfter]

Sorry, I don't have lots of time to check forums! But to try and answer so questions:
Technically you do not need a different post processor, and anyone that is not using our table should not use our sheetcam post because we use a macro for finding the top of the material. Switchoffset is in mach3 not sheetcam post.
What needs to be done to use early of is real simple (if using ethercut from candcnc)

Download the newest dll file for the smothstepper from candcnc website
delete the current dll file in the folder c:mach3/plugins and place the new one in that folder (note you can not have 2 of them!)
when you start mach3 go to the smoothstepper config and set up as the screenshot in the thread shows make sure to restart mach3
Make sure assigned to output1 and dwell is 0

in sheetcam, create a new G code snippet M10P1
now you can use it to create rules that "Before end x distance" apply the Gcode snippet you created.

The hardest part is finding what that distance in the rule should be. It will vary with every different material, and amp setting.

I am guessing most of you that need this are cutting open entities with no leadin or leadout? I ask because why not just increase your lead out if the divot is so large?

Thanks
Dan
LDR

[tnbndr]

I ask because why not just increase your lead out if the divot is so large?

Hi Dan:
For a lot of artsy stuff, lead ins and outs don't even work because the area is too small.
Also in some pieces detail is added with just straight or curved single lines, arcs, etc. so you get a divot at the beginning and end of the cut.
I have just learned to embrace the divot for what it is.

[dhelfter]

tnbndr
Thanks. As you know I don't do much artwork so my mind is always looking at mechanical cuts where there is typically room for a lead out.
Makes sense now.

[tcaudle]

I ask because why not just increase your lead out if the divot is so large?

Hi Dan:
For a lot of artsy stuff, lead ins and outs don't even work because the area is too small.
Also in some pieces detail is added with just straight or curved single lines, arcs, etc. so you get a divot at the beginning and end of the cut.
I have just learned to embrace the divot for what it is.

Its virtually impossible to eliminate a divot at the pierce point, especially on thinner material Try it yourself some time with a hand torch. You would have to pierce and instantly start moving BEFORE even the Z move from pierce to cut height. The difference between a full pierce and one that has a divot can be in the sub fractions of a second. Getting rid of the one at the end is easier because it's caused from the delay between the torch OFF signal and the actual loss of the arc / Turn it off slightly before the end and away goes the divot BUT the timing once again can be tricky. Using the M10/M11 to directly control the output to the torch works (provided you have the ESS and the latest ESS plugin) and the proper mapping in the ESS Config as shown. You still have to use the M3/M5 because they trigger other actions abut you cannot shut off (M10) an output unless you have turned it on with the matching M11

[exapprentice]

Following on from TC's comments above, just thought I would add this discussion http://www.plasmaspider.com/viewtopic.php?f=4&t=17739 onto this one.
Just to add more info and reading to those that are interested

[sr guy]

I ask because why not just increase your lead out if the divot is so large?

Hi Dan:
For a lot of artsy stuff, lead ins and outs don't even work because the area is too small.
Also in some pieces detail is added with just straight or curved single lines, arcs, etc. so you get a divot at the beginning and end of the cut.
I have just learned to embrace the divot for what it is.

I agree with Dennis. I cut a lot of bits spurs and buckles for buckle makers and horse halters. I compete with waterjet and lazer so any imperfections on the back are unacceptable. Some of the buckles range from 5/8 inside square to some design on the outside that is silvered and decorated. On the bigger industrial stuff no issue just the tiny stuff. Thanks for all the help Dan

[whiskeymike]

I am guessing most of you that need this are cutting open entities with no leadin or leadout? I ask because why not just increase your lead out if the divot is so large?

Thanks
Dan
LDR

Are you saying you should use a leadout on parts? I've read here many times that the leadout doesn't provide any benefit. I'm getting a divot on a 2" rectangle with a .3 leadin, no lead out on .250 mild steel. But the divot occurs on the end of the cut. I'll try it again and see if it makes any difference. I'm about to design a tab into the part that I'll grind off because the quality is so poor.

[davek0974]

I have spent way too many hours on this divot, lead-outs do very little and on internal holes where the slug drops out they make it much worse as the arc jumps back to the main part when the slug drops.

I'm currently using a 2mm over-burn and torch-off 1.5mm before the end of cut, still got a divot and most times a small tab is left at the end despite the over-burn.

I have a pile of test shapes on my bench over a foot tall where i have been messing over the time since starting cutting and probably more went in the bin, nothing i do seems to get the divot gone.

I just live with it now, position the starts where i can get a grinder on it and sort it out after.