Problem with 3D Parallel Toolpath

[winywohlwend]

Hello everyone

I'm a luthier from Switzerland and I'm trying to use Mastercam Home Learning Edition. Speak, I'am a real newbie.

Now I would like to mill the fretboard's radius. Therefore I made a surface with the exact radius which covers the entire fretboard.

First I tried with the 3D Parallel rouging toolpath but unfortunately I couldn't manage to get a zickzack motion. Although I configured the option zickzack it mills from left to right and then Z lifts up and goes back to start and so on. It makes no difference if it is configured or not.

(the frame around the fretboard is the clamping fixture)

Then I tried with the 3D Parallel finishing toolpath. Actually it would work perfectly but the problem is that the z axis is about 1mm too high and I'm not able to find out why.....

I configured a plane with WCS, C and T on the fretboard's surface. I also used the same plane for the toolpath above (3D parallel roughing toolpath) and there was no problem with the Z height.

I also configured the plane in the toolpath configuration

Does anyone have an idea where the problem is?
I would be very grateful for any help.

Winy Wohlwend

 

 

 

 

[#Rekd™]

Check your stock to leave on floors and walls settings in the Model Geometry section (where you select your geometry initially).

[billb]

Yes, check the stock to leave amount. In this classic surface toolpath, the drive stock to leave is found on the second tab page. 
 

Also, check the tool tip/center option also found on the second tab page. Maybe it is set to “center”. 

[billb]

Disregard my response. Rekd’s answer is correct - see stock on floors and walls in Model Geometry. Those may default to a nonzero amount. 

[Thad]

9 hours ago, #Rekd™ said:

Check your stock to leave on floors and walls settings in the Model Geometry section (where you select your geometry initially).

Also, check to see if you're programming to "center" or "tip" of the tool. (Sorry, but I'm not sure what parameter page that's on.) Center will show an offset toolpath like you're seeing because it's showing you the path of the center of the ball...which is up a bit off of the fretboard.

Another comment that I wanted to make is that since your surface doesn't have much shape to it (fretboard is only slightly arced), you could probably rough it with a finish parallel toolpath. As a newbie, you're probably thinking "I'm roughing, so I should use a roughing toolpath." The difference between the roughing parallel toolpath and the finishing parallel toolpath is that the roughing allows for step downs; assuming you've got a generous amount of stock to remove. In this particular case, you don't have much stock to remove so there's absolutely nothing wrong with roughing with a finish parallel toolpath leaving some finish stock, then using finish parallel again leaving 0 stock.

My last comment is that in this particular case, since the form is as shallow as it is, finish parallel should work just fine. Generally speaking, I recommend using the Blend toolpath for finishing. It does a better job of stepover on a wider variety of surfaces. You can see the difference between the two toolpaths with the right examples, but I'm not in the position to offer those examples to you. Perhaps someone else here is. 

***EDIT***  I just realized that billb mentioned the tip/center setting earlier. 

[winywohlwend]

Hello everyone

First of all, THANK YOU VERY MUCH for your quick replies, I appreciate that really very much, absolutely great!!

You guys were right, it was the "Check your stock to leave on floors and walls settings in the Model Geometry section" thing. There was 1mm on both, floors and walls.

Thad: THX for the tipp with the Blend toolpath, I will try that out.

I think I have come back to you guys with other issues.

Winy Wohlwend