Critical Depth cuts in V9 Help needed

[Johnny]

Hey guys

 

I am having trouble getting my head around the critical depth cuts methods in Surface Rough Pocket milling.

I am making a prototype for a cuastomer out of zinc from a surface model and there are a number of levels to machine to the right height.

I have used Surface rough pocket using Absolute depth cuts from top to bottom and have picked the critical depths I want to finish to height. I have allowed for stock to leave on the sides but have left the box unticked for stock allowance on depth cuts.

No matter what i do the program leaves material on these faces. I have tried everything and am having no joy.

What is the trick to this?

I just wat to be able to mill a pocket and have the levels finished as I go so can finish the outside with surface contour.

Any help much appreciated

 

Regards

 

Johnny

 

 

[ 10-22-2002, 10:05 PM: Message edited by: Johnny ]

[questech]

Johnny,

In the past I have used zero stock to leave on all surfaces and created a .504 cutter instead of .500 then actually ran a .500 cutter in the machine. This will give you .002 stock on all sides. You must pick all critical depths in absolute. I'm guessing you are using a flat or near flat e.m. for the rough pocket routine. It worked well for me several times.

[Johnny]

Hi and thanks for your quick response

 

I have tried that but it still leaves material on the levels I want to finish to height. I am using a Bull cutter e.g 5mm diameter .5 mm radius.

The only way I got it to finish the levels was to make the stepdown a figure that fits evenly in between all the levels. Fortunately .05mm stepdown was ideal, BTW this is a small part so I am using small tools. When I initially roughed out the part I had picked the detect flats option and was expecting all the faces to be finished and only stock left on the sides for finishing. This was not the case.

I have since read some earlier post to the forum and it looks like it is not possible to do what i want to do.

 

Johnny

 

[ 10-22-2002, 10:00 PM: Message edited by: Johnny ]

[Fred from Université de Sherbrooke]

Johnny,

Just a thought, did you try: stock to leave=zero and check surf.=the value you want to leave and select the walls as check surfaces. Maybe...

[Allan]

Fred, surface rough pocket has no check surface option. (good idea tho.)

[cadcam]

The only way I can get it to work and go and finish the flats was using "Depth cuts" then "Absolute" then "Select Depths and this would finish the top and still let me leave .02 On the walls.

JM2C

[Johnny]

Yep can't use check surfaces in Rough Pocket, tried that the select check surface box in greyed out. Still stumped with this one. I was lead to believe V9 took care of this issue where V8 didn't.

At this stage using when Absolute it looks like I have to forget detect flats or critical levels then isolate the faces I want to finish within a boundary and make a small series of level cuts that will finally machine the faces to height.

Anyway i finished the job using that method and it came out great.

 

Thanks guys for you input into this problem.

 

Regards Johnny

[RHart]

Hi, This is my first post in here.

 

We currently use Virtual Gibbs Solid Surfacer and we are considering buying a seat of level 3 mastercam plus Solids. When we had the local var come out and do a simple program on one of our parts, we ran into this issue. I need to be able to finish floors and especially the top of bosses and ribs before finishing the walls.

 

In Gibbs they have three values for roughing; surface stock, pocket stock, and island stock. This way I can specify 0 surface stock, and .020 pocket and island stock which will finish the floors but stay .020 away from all walls.

 

The work around in Mastercam was to create another tool, with the same tool number, and lie about the o.d. But I can see this having adverse effects on any rest milling operations that I would like to do later on, the system thinks those walls are done, but their not because I lied about the tool.

 

Any comments?

 

Roland

[Johnny]

>The work around in Mastercam was to create another tool, with the same tool number, and lie about the o.d. But I can see this having adverse effects on any rest milling operations that I would like to do later on, the system thinks those walls are done, but their not because I lied about the tool.

 

Roland

 

I couldn't get this to work either. You have an option in restmill to tell it what size cutter you used to rough with. Even if you lie about the size of the cutter in roughing you could tell the truth about it in restmill, I'm sure that would work fine. It would only be a problem if you used the roughing operation as a basis for the restmill process.

Sounds like Gibbs has the machine faces problem solved. As I said in an earlier post, I was lead to believe MC9 was up to speed here as well.

 

Thanks for your input

 

Johnny