Version 18 3D Question?

[Konrad]

I'm practicing Version 18, using Training Guide, but can't seem to find a appropriate example, on how to skin this profile. This is something I have to pre - mill and EDM the rest.
I have managed, to do it in 3 steps, middle, right and left, but like to have only one toolpath!
If I would try hard enough, I probably could do it in version 17, but I need to go on with newer version!
Any help appreciated!
Konrad

[HuFlungDung]

Hi Konrad,

IIRC, skins may be created from spline lines drawn internally in the program. Although an actual spline is not output on your screen (instead it will be lines and arcs), there is a rule of splines to observe: sharp intersections create distortions. That is to say, a spline will be drawn, but it will never conform exactly to the sharp corner of your design.

So, if you can fillet the bottom creases of the part, you may be able to make a single skin (somehow). In actual fact, whatever ballmill you use is going to create some kind of a radius corner in the part. But, if the ball radius is exactly the same radius as the final radius on the part, then regretably, the toolpath will have a sharp corner in it, and I don't think it is then worthwhile to pursue a single skin toolpath. If you achieve it, it will have distorted corners.

Its much handier to move on to a solids based cadcam and let it figure out the path. That way, you can concentrate your efforts on designing actual part geometry, instead of guessing about tool offsets, etc.

[Konrad]

Thank you HuFlungDung, makes sense!

I'm surprised, you could open the file, [my first one], how come, I couldn't open it myself??

Can you do it in Version 19, [Solid] with ease??
Konrad

[HuFlungDung]

I opened it in another program.

Sorry, I cannot personally recommend Bobcad 19, but I'm sure other users out there would be glad to help you out with an opinion.

[The One]

Konrad,

I had no trouble opening the file in V19.8. I was wondering if the original part geometry is available. There is probably an easier way to do this in BobCAD.

A couple of questions though:
Is the path on the screen the actual path you are trying to cut, that is, is it already offset for your tooling?
Is there a file available with the original geometry?

If you could post the original part file in a .cad format I can help.

Regards

[Konrad]

The One,

thanks for your post!

Strange, I can't open my own file??
Have tried about 4 times, the screen freezes an I have to reset computer!

Sorry, can't get the actual CAD drawing, I have not offset the tool path, [should have done it]
but when you look from the top, 2 D , the outside is the actual shape.

I'm not too worried about, by not getting the correct tool path, because the costumer wants sharp edges and I have to finish it off by spark eroding EDM anyway.

You might say, why not EDM into solid ?
It's because my old EDM sinker has allot of electrode wear, so by removing as much material first hand, will save me from re- shaping electrode.

There is still some unclear cavity drawing, which has to be discussed first, but practicing first is always a good thing.

thanks
Konrad

[The One]

No worries, If you want to place your old cad file up here I can see if I can determine the error. I have seen this before in many different files. The porblems weren't always the same, so by looking at the file itself I think we can get you up and going no problem. I will also post a little later on how to accomplish this in your current file, it takes a little time to get all the details.

What size and type of cutter are you intending to use?


Regards

[HuFlungDung]

Konrad,
Clean out your username /local settings/Temp folder. It used to be that if Bobcad terminated abnormally for some reason, it would then attempt to reopen the corrupted version of your file (its always got a working version of your file open in the Temp folder), and this could be the problem. Once that temp version of your file gets killed off, then this forces the program to actually go and open the file from its current saved version on your disk.

[Konrad]

Thank you both, for your help!
My son cleaned out temp. file, tons of rubbish, I'm still handicapped on computer!
Still can't open it!
Saved it, that way I can open it.

Hope, in the next few days, I will get a CAD drawing from my Customer, then I will post it.

I like to use a 1/8 Dia. endmill, that way, I possibly don't need a ball, if I don't go all the way down to depth, perhaps larger, bullnose type, lets say about 1/4" dia. with about 1/16 radius on the edge.

Konrad