[Mortek]

Just curious for you guys who have xp. Please try to explain how custom toolpaths work. The demo isn't real clear on how this happens. Do you just pick a particular surface and it machines only that surface or do you pick a surface and then pick the surfaces that you want to avoid?

[steveg50]

You make a 2D tool path , I use the boundary , make sure it iis a seperate layer and directly over the surface you want to machine. It will then follow that path only on the surface . This is better than projecting a curve since it will prevent your tool from gouging the surface on sloaps,ect . As far as making the tool path you can use a backplot from the toolpath section . Or if like me you also have Mill Pro 2000 ( maybe even Bobcad ) you can draw manual tool paths and import them into XP. I have been in touch with the man downunder and he says version 5.20 will add more of these older features for use with this funtion. If you do alot of surface cutting you'll end up loving this function .

[Mortek]

doesn't this also work in 3d? Then do you have to draw the boundary or can you select other surfaces that you want it to avoid as in surfcam?

[Mortek]

There is a picture of this part under the "I'm shuttin my mouth about onecnc" thread, listed under my name. I'm trying to machine the boss on the back side without touching the flat surface. Also I couldn't get the fillets create. I need a 3/8 fillet on the front of the boss and a .125 around the rest of the boss.

[steveg50]

That is a 3D surface , the tool path layer ( the 1st box that comes up with this fuction ) is the orange part in that picture. The green is the back plot and you can't see the surface . Heres one with no back plot or tool.

[steveg50]

Heres a front view

[steveg50]

I think with alittle trial and error and the custom funtion . Along with manual tool paths and or backplots you could finish that. I have found the only thing that limits me is me .

[HuFlungDung]

Originally posted by steveg50
I have found the only thing that limits me is me .

Hi Steve,

That looks like a good line for a signature. Want to claim it?

[steveg50]

How would I do that?

[HuFlungDung]

Just go to the top of the page "My CNCzone" click, and select edit profile and then cut and paste your remarks in the signature dialog.



Mortek, so far as which surfaces get machined, what I do at the present time (not saying this is the way) is create a quick "cover plate surface" to put over top of any area where you don't want the tool to descend in to if it lies inside your main boundary. In some cases you can limit the tool movement by specifying a bottom of job that is not the "real bottom" but will serve nonetheless to prevent further pathing downwards where you may not want it to go.

Each case is a special case, so it's next to impossible to give a hard and fast rule about it.

It should never be necessary to use another program to create the 2d path. Once you have a boundary, create a quick planar surface beneath it, and then perform a pocket routine inside your boundary, at the fixed depth of the surface. Backplot this code and save it on a new layer as the custom path you intend to use. You can delete the nc process that you used to create this backplot.

Does this sound reasonable? I haven't done it but I think this would be my (newbie) approach to it.

[HuFlungDung]

Mortek, just studying your part in the other thread a bit, about filletting, I too have troubles with that. I can envision the problem with the spots where the 1/8 and 3/8 fillets might meet. Also, I suppose the boss is just sitting on top of a large flat surface?

I've got a theory right now that you need to have intersecting surfaces, but not overlapping surfaces, because the overlap cannot trim properly for the fillet. This would involve breaking up your large flat surface into chunks that mate with a single given surface of the boss, kind of like equalizing chains before skinning in Bobcad.

In a situation I was working on, I could not draw the fillets, but I could cut them okay with a ballnose tool, so I didn't sweat the details of filletting. It looked right in the simulation, that's all I needed to see.

For your custom 2d path, you would create a boundary that represents an offset around your boss as an island. Then, when you create the 2d path, you would use this boundary as an island and the outer perimeter boundary as the outside of your pocket. Then follow the procedure I outlined in the post above.

[Mortek]

I can't do that in mill 2000. What I have done is created a surface of the .375 fillet so that when I finish it with a .25 ball mill I will get my .125 fillet around and still maintain a .375 fillet in the front face (where the hole is). I've created a boundary to keep the tool from wandering out where I don't want it to. I just happened to see my customer take my model in surfcam and pick the surfaces he wanted to machine, then he picked the surfaces he wanted to avoid. It created the tool path without creating a boundary, it was so slick I couldn't believe how easy it was. He didn't have to set a tool path angle either, which I have to do. Of course I believe Surfcam is about $15,000. It better have a few better features for the price. I just wanted to know if XP addressed custom tool paths simularly.

[HuFlungDung]

Did you try machining the surface as a pocket, so that you too, could pick the boss as an island. A pocket doesn't have to be a depression, an island (the boss) is just a collision area. Even though the rest of your surface is flat, does not mean you cannot call it the bottom of your "wall-less pocket"

[Mortek]

Boy, I guess I can't picture what you are saying. I was going to machine the flat surface with a 3/4 end mill, leaving a raised block for the boss, then go in with a 3/4 ball mill to rough the boss using planar roughing, then finish the boss with a 1/4 ball mill using planar finishing so I will get the .125 fillet all around the boss except where the 3/8 radius is drawn as shown in the above picture.
Don't you want to just grab that part and rotate it around to see what it's all about?

[HuFlungDung]

I know it can be difficult to picture a different method, I've found myself in the same situation a lot of times with Onecnc, but I've found that there are usually more efficient ways to do things that just were not part of my thinking patterns yet.

What you described the other person doing in surfcam sounds like island avoidance to me. This means you need to use the pocketing routine which allows you to pick islands for the tool to avoid, does it not?

The trick is visualizing that the large flat area is a pocket and the boss is an island. If you like, raise your boundary up to the height of the top of the boss, and imagine that this is the top lip of your pocket. I am assuming that you orient this part so that the flat surface is in the XY plane.

You may need to sketch in a 2d boundary around the boss (extract the edges of your fillets) to serve as your island, this I am not sure of how you would handle it.

[Mortek]

So does that mean that it is going to machine the boss or the flat surface? You have to select wireframe geometry when using the pocket routine don't you? I've tried what you said selecting the surface geometry and it doesn't work that way. I know I'm probably sounding a little dense right now.

What it seems you are describing is what I was trying to explain about roughing down the flat surface with the 3/4 endmill leaving the boss unmachined as an island, or in other words clearing all the material around where the boss will be.

Is this correct? If so I have done this many times to clear the material.

[Cruncher]

We cut particular faces in Onecnc all the time thats why we use it all the time now instead of our Mastercam. We have both. We never blank any surfaces in Onecnc that is very important not to do that. The software is so brilliant when you just select a surface to machine it automatically knows where all the rest of the model is and avods them all the time. We just finished a mold for a new type machine base and there were 85 individual shaped surfaces on the bottoms that we wanted to remachine instead of polishing and there were 470 other surfaces to avoid and it did it perfectly. This was around 32 inch square for the part and 4 inch joint all round. Tech support told us never ever blank any surfaces. When the model is solid they have a function called disconnect surfaces if you use that it unlocks the surfaces of the solid and allows you to select the individual ones that you want to cut and you dont have to select the ones to avoid. It takes complete control of that itself. It is real easy to do. Set your clearance plane and plunge amount and it automatically takes care of the rest. After using it you wouldnt use anything else. You guys are so good with your digital pictures I asked management if I could post one to show but they said we have a secret agreement with the customer and said big no. They also said it would give away the fact that we are now doing molds off tool without polishing. That is saving big time for them.

[HuFlungDung]

Cruncher, Mortek is working with Mill2000 at this time. The constraints he is under would be different than with XP. Can you comment again, with this factored in?

[Mortek]

I never do blank surfaces, but if I select an individual surface mill 2000 will cut on other surfaces in addition to the one selected, unless I create some kind of boundary and select pick boundary in cut model.

[Kingkong]

Originally posted by HuFlungDung
Cruncher, Mortek is working with Mill2000 at this time. The constraints he is under would be different than with XP. Can you comment again, with this factored in?

Hi, I#m working with 2000 Professional. There seems to be no difference on this item.
I do it same way. Only one remark: this works only with 3D-milling, not with pocketing etc. For pocketing you need boundaries, but most times there is no reason to work with the pocketing function (I never did)

Kingkong