(Help) 3d rough casting

[ChrisH]

Hi,

Im trying to rough a 3d casting. I would like some help on the best way to keep the tool on the steel. I can't seem to get anything to work the way I want it to. I don't have a book for mastercam and I'm just starting to use it for all my 3d jobs. In the past I used WorkNC for all my 3d.

[robk]

Chris,

More info would be good... What kind of toolpaths are you trying to use? Solids, surfaces?

[ChrisH]

I'm roughing 3d runoff on a cast trim steel for a line die. The castings are about 15mm heavy. And I have to rough them and finish the 3d trim edge. the trim edge is about 25mm wide. They are for final trim on something like car body side or fender.

[mayday]

Hi Chris. you cant really define a casting for 3d roughing you will get air cuts. 1 of those wish fors I guess. you may want to run multi finish 3d cuts to get it to drive on the surfaces. if all else fails call Joel B. from axsys. I think he is usually around Grand Rapids most of the time. I'll be in Grand Haven 2nd weekend of July if you want to bring your laptop to the beach I'll help ya out

[Müřlıń®]

Create a 3-d boundary around part. Create/curve/one edge..............slide to desired edge.

 

Make sure your boundary chains or it will retract.

 

Use 3-d contour to machine around the outside of your part.

[ChrisH]

I tryed 3d contour and i can't get it to step down it wants to take all of the 15mm in one step. I need it to work down like a pocket rough would.I have 4 small mill that can only take about 1.5mm depth of cut with a 1" cutter.

Is there a place to put that there is 15mm of stock over the solid/surface?

[g huns]

What it sounds like you need is a surface rough constant scallop path. Maybe in X.

[Müřlıń®]

Use depth cuts and multi passes. If this does not produce the desired results, array the toolpath. then rearrange them in ops to take the stepdowns in the right direction.

 

be sure to use retract and clearance on arrayed toolpaths that are posted together.

[ChrisH]

Are you talking about 3D there is not multi pass in surface / rough / 3d contour?

 

(I'm roughing 3d runoff on top of a cast trim steel for a line die)

[g huns]

Chris I think you could use surface finish scallop and create a path that leaves 13.5mm on your drive surfaces. Copy it and leave 12mm and so on. Kind of a PITA but might work for you. Good luck.

[Thad]

A method that has been mentioned here in the past is to program a Surface-Rough-Pocket leaving your approx stock (15 mm). Then create a Restmill toolpath referencing your rough pocket. Don't run the Surface-Rough-Pocket, just run the Restmill.

 

I believe it was Iskander who originated that one.

 

BTW, there was a fairly recent thread on how to eliminate air cutting on Restmill toolpaths. You may want to search for that also.

 

Welcome to the forum!

 

Thad

[ChrisH]

That sounds like a good plan. Ill try it right now!!

[crazy^millman]

I would look to finish toolpath and then use my material to leave as my way to rough it in. You may do 2 or 3 finish pass type paths to create step cut but not a big deal.

 

HTH

[Müřlıń®]

Chris maybe I was not understanding what you were trying to do. I was thinking you were machining flash off the outside of a part that had a 3d shape to it.(not flat)

[Mike Mattera - TFM]

Surface - Rough - Contour.

 

Why wont this work? It cuts around the outside. You can adjust the stock and depth. It does not assume a solid block. I thought that's what this toolpath was for (castings).

 

Mike Mattera

[ChrisH]

I tryed it and if it to a flat spot it went right to depth. So if there is 15mm on the casting it takes a full 15mm pass deep. Maybe I did not set something up right. What tells it how much stock is on the casting?

 

 

Chris Hillary

[Müřlıń®]

quote:

---

Are you talking about 3D there is not multi pass in surface / rough / 3d contour?

---

What I was talking about was cutting the parameter with a simple contour, using a boundary and no surfaces.

 

You can choose from a 2-d or 3-d cut. It will do multi passes and depth cuts.

 

Murlin teh why use surface when a line will do

[Gary]

Stock Model recognition. Man now thats the life. Could you do a surf rough pocket with 2 boundries and absolute depth cuts to control the first depth of cut so it don't start at the top of the part. Will still get air on the lower valleys though. I like Rons finish path ideas the best.