Surface toolpath

[Julian M]

Hello everyone,

I have attached a zip2go file containing a part that i am trying to machine, i have also put some toolpaths on. I was wondering if someone could look at it for me to see if theres a better/more efficient way of doing it. Have i gone about it the best way? My aim at this stage is to machine the inside only with a good surface finish. How do i create a surface to close in the ends, I have tried most of the create surface options with little success. Thanks

Julian

[Matt Berube]

Originally Posted by Julian M Hello everyone, I have attached a zip2go file containing a part that i am trying to machine, i have also put some toolpaths on. I was wondering if someone could look at it for me to see if theres a better/more efficient way of doing it. Have i gone about it the best way? My aim at this stage is to machine the inside only with a good surface finish. How do i create a surface to close in the ends, I have tried most of the create surface options with little success. Thanks Julian

Hi Julian,

If it was something I was cutting I would only use the "bull" style tool for roughing. When finishing I would switch to a ball end mill.

I would change the order of operations to have the surface finish contour BEFORE the shallow ops. This will reduce the chance of burying the side of your tool into any material on the walls of the part during shallow cuts.

In the contour operation, you could use the "shallow" box to remove cuts from shallow areas. This should help you get a better surface finish.

I use the contour (restricted with shallow box) and shallow ops together more often than any other finishing tool path. It is a great combination.

Another thing I noticed is that you *should* be able to combine ops 4 & 5 by simply adding the second containment boundary to op 4. I just wanted to make sure you know this is an option.

Now for your question:

When you say "close in the ends" I assume you want this to keep the strength of the part until the very end, right ?

See in the attached picture...

Would this work for you ? It is a quick simple way to avoid certain areas. add the surface as a drive/check and everything below it should be left alone.

I created it by using "create curve one edge" from the surrounding surfaces and then making a ruled surface between my 2 "curves".

[Julian M]

[QUOTE=Matt Berube;242131]Hi Julian,
Now for your question:

When you say "close in the ends" I assume you want this to keep the strength of the part until the very end, right ?

See in the attached picture...

Would this work for you ? It is a quick simple way to avoid certain areas. add the surface as a drive/check and everything below it should be left alone.

I created it by using "create curve one edge" from the surrounding surfaces and then making a ruled surface between my 2 "curves".

Hi matt, thanks for your input on this i will try out your suggestions once my little lad goes up for his afternoon sleep!

Yes you are right i want to keep the ends in for strength, its something that i regularly need to do but can never work out how to create the right surface in the right place. The surface terminology/definitions takes a while to get the hang of. Are there any basic rules to remember when adding surfaces like this? Again i will try creating the surface your way this afternoon.

Also i have tryed selecting check surfaces in the past but it doesnt let me am i doing something wrong?

Cheers Julian

[Matt Berube]

Some ops don't support check surfaces. I actually avoid using them when I can because they can be a nuisance at times as well.

Another quick and dirty surface to create would be "flat boundary". You can create this on any "planar" closed chain. If you have a contour which does not lie in a flat plane, use the xform project tool to make it flat.

I can't really think of any rules to give... I am sure you can see that in Mastercam there are 10 different ways to do almost everything and it all really comes down to user preference...

A few tips would be :

1. the surface doesn't necessarily have to be at the same height as your part. My example would work just as well if the surface was several cm above the part.

2. You may have to specify ABSOLUTE "cut depths" to achieve the desired result...

3. If using check surfaces, try to use a slightly different "stock to leave" for drive and check surfaces... example: drive.000mm, check -.001mm. The resulting toolpath will be smoother and with such a small stock to leave difference you'll most definitely not see any gouging or leftover stock...