Electrode toolpaths

[wilcocad]

When creating a program for electrodes w/X-MR2

what are the settings to creat an .005 orbital over-burn in surface finish tool paths. I have used cutter dia. to do 2D over-burn with good results (1/8 ball EM Dia is .115).

 

If any could help me out I would really appreciate it!

 

Thanks.

 

Martin

[Moldmaker74]

I always use "stock to leave" as a negative value equal to your overburn and leave the cutter diameter at the true value.

 

Edit: Remember to calibrate your tools above the top of your electrode by the overburn amount so the top of your electrode remains Z.0 when your cutting.

[Jammer™]

+1 to Moldmaker74

I never liked the idea of "lying to the cutter".

[edmBosto]

I like to lie!

[Redfire427]

The only drawback to using negative stock is when you have to use a sharp corner tool. In this case you must lie about the diameter.

[Kannon]

I lie all the time..now can blame it on my job. I use negative value all the time..

JUST KIDDING I have to lie about the cutter size.

[Midwest]

+1

 

 

 

 

 

 

Now is this for a.........

 

1. Moldmaker

2. Toolmaker

3. Machinist

4. Die Maker

5.

 

 

[Moldmaker74]

Prisn Molds

Why wouldn't you use XY and Z stock to leave with a sharp corner tool? I would think it would be confusing to switch between methods.

[edmBosto]

Ever try cutting a surface with a flat tool leaving -.005 material?

Calling a 1/8 flat cutter .115 works.

[Redfire427]

Moldmaker74,

 

If you are using negative stock, you would want negative stock on all areas of the electrode, including flats for example. For the flat areas you would typically use HST horizontal to get the best toolpath. You have different fields for xy stock and z stock. It is not possible to put a negative value in any surface toolpath when using a flat bottom tool ( sharp corner ). If you were using a 1/4 bull nose endmill with a .020 rad and your electrode required a .005 spark gap, Mastercam will basically subtract your spark gap from your tool info to calculate the toolpath. So in other words its the same thing as programming a .240 dia tool with a .015 rad and cutting to zero stock to leave. If you try to subtract the spark gap from a sharp corner tool, in essense, you end up with a negative radius which obviously is not possible.

 

What we do on our Makino that we use for electrodes is: If using a sharp corner tool, you define it as a bullnose endmill with its true diameter and the corner rad is whatever the spark gap is. Merely lying about the diameter is not going to help as some others have suggested because that is only compensating in the XY direction. You still cannot leave negative stock in Z with this approach. ( Yes, I know there other ways, but I'm trying to keep it simple )By only lying about the corner rad, you cover all basis and get no errors and correct electrodes.

 

Don't know if I helped or confused you.

[Moldmaker74]

I see what you are talking about now. I just sound retarded because I don't think I have ever used a flat bottom endmill in a surface program before.

 

I should also be embarrassed to admit that I haven't used HST horizontal either (I'll check it out today though). Thanks for the explanation. I'm not working in a mold shop right now and haven't been doing many surface paths since switching to X, the last mold shop only had V9 so no HST.

[Rick46]

quote:

---

Moldmaker74,

 

If you are using negative stock, you would want negative stock on all areas of the electrode, including flats for example. For the flat areas you would typically use HST horizontal to get the best toolpath. You have different fields for xy stock and z stock. It is not possible to put a negative value in any surface toolpath when using a flat bottom tool ( sharp corner ). If you were using a 1/4 bull nose endmill with a .020 rad and your electrode required a .005 spark gap, Mastercam will basically subtract your spark gap from your tool info to calculate the toolpath. So in other words its the same thing as programming a .240 dia tool with a .015 rad and cutting to zero stock to leave. If you try to subtract the spark gap from a sharp corner tool, in essense, you end up with a negative radius which obviously is not possible.

 

What we do on our Makino that we use for electrodes is: If using a sharp corner tool, you define it as a bullnose endmill with its true diameter and the corner rad is whatever the spark gap is. Merely lying about the diameter is not going to help as some others have suggested because that is only compensating in the XY direction. You still cannot leave negative stock in Z with this approach. ( Yes, I know there other ways, but I'm trying to keep it simple )By only lying about the corner rad, you cover all basis and get no errors and correct electrodes.

 

Don't know if I helped or confused you.

---

If Im understanding you correctly here the follwing example would achieve my required results by using your method.. example being .250 flat endmill need a -.010 Overburn per side on electrode.. I would call out a .250 bull nose end mill with a .010 radius on cutter and then when I toolpath the electrode use the above mentioned and input a .010 negative stock statement to achieve my -.010 per side Overburn on my electrode..

[Redfire427]

sr_7626@natl,

 

That's exactly the way to do it.

[mold100]

I have used all methods in the past 14years, I will mix it up in an electrode using both negative stock with ball and bull nose ctters and pick bottom corners out with 2D paths and adust stock settings accordingly. Also if i have a drafted contour with a sharp bottom that I have to actually pick out I will lie about diameter and also drop the Z offset of that particular tool to blend everything out. Its rare that I do that because I am also designer and will alter model if I can. On same occasions with complex electrodes I will incorporate all these paths in same program. Alot of times though i will just break the trode up into a few versions to get all the features just using the negative stock method, it is hands down the quickest easiest way to get a trode from the screen into the steel.