Detect flats

[Thad]

I've uploaded DETECT FLATS.ZIP to the FTP. No matter what I do, I can't get the toolpath to finish at the correct depth. I'm referring to program 3. Just to give you the run down, I ruff it with a 2" face mill as deep as I can in prg1, then pick the corners with a 1" face mill in prg2, then finish it to depth with a 1" face mill in prg3.

 

It should finish at Z2.430. I've tried changing my step down slightly, with no luck. I don't want to check "Adjust for stock to leave on drive surfaces" because I want to finish the depth.

 

This is the file that I was talking about in my "Mirroring surfaces" thread. If you get a chance, try mirroring the file, then regen prg1. Does the nc file size double just by mirroring it? Does the absolute retract in the NC file change to Z9.22, instead of Z9? I think I know the reason behind this, but why does it go to Z9 in the original file, but then Z9.22 when mirrored?

 

Thad

[cadist]

I have not yet seen your file but have you tried tlpcfg chook of sp2. I found it's autodetect feature very reliable.

[Thad]

Cadist,

 

No I haven't. I didn't know it existed. Thanks.

 

Thad

[cadist]

[mayday]

you can use auto detect and or select criticle depths to make sure the tool reaches those surfaces. Ive done it both ways

[Thad]

Mayday,

 

I've tried them all, and none of them get the job done.

 

Thad

[Midwest]

Thad,

 

Looked at your file you have leave .025 stock on your drive surfaces. If you change to 0 stock it cuts to depth.

[Thad]

Midwest,

 

Then it also cuts my surfaces to zero, which I don't want. Is this the only way you got it to work?

 

Thad

[Midwest]

So far yes, but I have to get back to work.

 

You could add .050 to your cutter dia if you want to leave stock on the sides only as a quick fix, since you are roughing.

 

HTH

[Code_Breaker]

Thad,

 

I have looked at your file . . . the problem you have is cause by STOCK TO LEAVE .025. Since you are using a 1.0 cutter, this is what I have done to FIX the problem. Change cutter dia to 1.05 and STOCK TO LEAVE .000. This will accomplish what you are looking for.

 

 

Hope this helps

 

Code_Breaker

[Thad]

Sorry guys but I don't believe for one minute that you can't leave stock when using the detect flats feature. There is even an option of whether to adjust for stock on drive surfaces.

 

Thanks for taking the time to look at it.

 

Thad

[Salahuddin]

as Midwest said adding .050 to you cutter dia is very good way if you want to leave stock on side only, I think this is what you want Thad.

[Thad]

I just remembered...in the process of experimenting yesterday, I was able to get it to stop at Z2.500 with no problems.

 

Thad

[Salahuddin]

as Midwest said adding .050 to you cutter dia is very good way if you want to leave stock on side only, I think this is what you want Thad.

[Thad]

Salah,

 

I appreciate your input and I don't doubt that your, Code Breaker, and Midwest's method works. I'm not looking for a workaround. I want to know why the feature doesn't work. Am I doing something wrong or is it a bug? Thank you all for your replies.

 

Thad

[Salahuddin]

ops

[Thad]

Salah,

 

No need to "oops." I appreciate you taking the time to answer.

 

Nice website. I played with the spinning block on your home page for a few minutes. Are you in any of the pictures?

 

Thad

[Salahuddin]

I make ops fot the my second post, it was mistak , not for your post :-),

any way I need this future too, hope it will be in VX, to control leaving stock in xy, z as 2d pocket.

another future I hope to have is to have Taperd wall in contour to accept the min -, this well help a lot in under cut work, hope to see it in VX.

[Glenn Stephens. from CCCS]

The feature is doing exactly what you asked it to. Your "bottom" surface is at Z2.43081 and you've told the toolpath to leave .025 on it, thus a max depth of 2.45581. That is going to override ANY settings in the depth cuts. Since you're using the depth cuts to limit your Z anyway, de-select the flat surface in the drive geometry and regen.

[Thad]

quote:

---

That is going to override ANY settings in the depth cuts

---

Even the setting (that is unchecked) that says "Adjust for stock to leave on drive surfaces?" Here is the quick help for that option:

 

"Modifies the depth cuts to include the stock to leave on drive surfaces set on the surface parameters tab. When cleared, Mastercam ignores the stock to leave and only uses the depths you have selected ."

My emphasis in bold.

 

Thad

[Code_Breaker]

Thad,

 

Another way, at least in your file, is to leave out the bottom flat surface. When I did this to you file, the cutter went to 2.43081.

 

Just another way of doing something. If you really NEED the surface, then translate it down .025.

 

Anyway, like you just said, maybe it will work differently in VX.

 

HF

 

Code_Breaker

[Thad]

For those interested, the job is done and gone. It got finished yesterday afternoon. At this point, it's just for conversation's sake so the next time I can do it right the first time.

 

A few questions here...Why won't it go down to Z2.40381, but it will go down to Z2.5? Based on the help, should this work the way I think it should? What is it about that surface that won't allow the tool to go that deep? There is got to be something that I'm missing here. Just thinkin' out loud here. Somebody smack me if it's right in front of my nose.

 

I do appreciate the alternative ideas on how to get this done. I have learned something new in this thread.

 

Thad

[DavidB]

My 2 cents,

 

If you have a positve stock value on a surfaced modal it will leave your 0.025 all over.

 

If you select a deepth and say add stock to deepth it will give you exact stock thickness at your deepths because your adding the stock value to your deepths selected.MC can't cut to your deepths because the toolpath has a stock value.If you unlest add stock to deepths you will not have the exact stock you asked to leave at your flat ereas due to the step down you make.

 

Just my 2 cents

 

 

[Thad]

Does anyone else have anything to add to this? So far I'm not satisfied with the answers I've received and wish to discuss it further.

 

Thad

[Eazy]

I usually use the 'adjust for stock'. If you dont, and you pick critical depths, it wont m/c them. You cant expect it to machine a flat surface to the finished height when you have told it to leave stock on that surface.

I agree, either unselect that botom surface, or tell MCam the cutter diameter is bigger.

 

Hope this helps.