Sign in to follow this  
navsENG

Restmill not going to full depth

Recommended Posts

Hello, I was having an issue with the restmill toolpath . My settings were to leave .01" on the drive surface , but it is leaving more like .03-.04" 

You can see in the attached photo , I went in with a 3/8 to rough the pocket and tried to come back with a smaller tool and hit the corners but it won't go all the way to the floor. Almost like it skips a depth cut ?

I have changed my depth cuts to absolute and selected the floor. As well as depths deeper than the floor and it still wouldn't go. 

Is there a better toolpath to use to come back and cleanup corners / small areas the bigger tool can't reach ? I know other paths have a rest material stock. I ran out of time today so I figured I would ask ..

 

Thanks 

IMG_20200219_162011.jpg

Share this post


Link to post
Share on other sites

Can you share the file? It will take the guesswork out of this.

Share this post


Link to post
Share on other sites

Restmill is really a development of Surface Contour and that was not designed to machine flat areas.  That ability was added to Surface Contour later but from what I remember (been quite a while since I've used it) Restmill still doesn't target flat surfaces.

You could try Optirough and activate the Stock page to make it behave like a Restmill style operation. Set the stock to leave on floors in the Model Geometry page to zero.

Share this post


Link to post
Share on other sites

What I find is a little math is involved. If the depth is not in the perfect place within the depth setting you will see this behavior. By playing with depth of cut and the steep shallow I can always get it fixed. Yes a real pain, but once you understand the math behind the process you see the solution. Say you leaving .05 in the floor. Then set you depth in the steep shallow to +.05 from the deepest point. Then you need to see what your top of stock it. Lets say we are cutting 3.567 deep and we have set a depth of cut as 1.75 on a 1/2 endmill. We do the math and we have 3.567/1.75 we get 2.0382 cuts. Not all that good. If we do the math the other way and take 3.567 and divide by 2 we get 1.7835 for a depth of cut. Now we will see we get a nice process, unless we are dealing with different depths. Then all bets are off. I will then sometimes have to go back and do a section at a certain depth. I will copy the operation and create a .01 to .02 steep shallow for that missed section and now I know it gets cut to where I expected it. I wish they would change the whole process to be depth aware and logically sort the motion in ways that not only took what they have, but looked at other more practical issues. Thin webs. reduced walls and other things are not considered as part of the calculations. What mass of the section are you cutting? What is the depth to length for a thin web they are leaving and other things that I feel should be part of the math. Maybe they will get there, but mathematically I feel they are leaving a lot on the table that could be done.

I am the crazy^millman so take what I say with a grain of salt.

  • Like 1

Share this post


Link to post
Share on other sites

If you use Opti-rough with the stock pages active for rest machining then activate the "stepup" check box then it will be able to alter the depth of cut due to stepup and will manager to make a smaller depth of cut at the bottom to avoid missing any material, or you can use the 3d area roughing with the stock page, that toolpath would require the "add cuts" button turned on with a minimum stepdown set (sett for lets say .01" for minimum step down). both of these toolpaths will finish the bottom floor properly with rest material as long as you use the "stepup" setting for optirough or the "add cuts" setting for area rough, without those settings active it will produce an exact stepdown which could in turn end up leaving extra stock on the floor if there isn't enough room to fit an entire pass in. 

I find those paths are much more modern and better than that old rest toolpath anyways in my opinion. 

Share this post


Link to post
Share on other sites
1 hour ago, JoshC said:

If you use Opti-rough with the stock pages active for rest machining then activate the "stepup" check box then it will be able to alter the depth of cut due to stepup and will manager to make a smaller depth of cut at the bottom to avoid missing any material, or you can use the 3d area roughing with the stock page, that toolpath would require the "add cuts" button turned on with a minimum stepdown set (sett for lets say .01" for minimum step down). both of these toolpaths will finish the bottom floor properly with rest material as long as you use the "stepup" setting for optirough or the "add cuts" setting for area rough, without those settings active it will produce an exact stepdown which could in turn end up leaving extra stock on the floor if there isn't enough room to fit an entire pass in. 

I find those paths are much more modern and better than that old rest toolpath anyways in my opinion. 

Problem is how you may need to rough something sometimes. I find in hard metals I want to rough all the way down not lifting until I get to the correct depth. I then want to step back up in a different operation since on hard metal we need even wear as much as possible on the full flute. Not an issue on soft metals, some steels and tool steels do okay, but on Inconel, Ti and other harder to machine metals I am finding its best to keep the full depth engaged longer then work back up after that bulk of the work is done and produces better and longer tool life by as much as 50-75% in doing so. In those situations I find using what I mentioned above the best process to make it happen and ensure i leave material like I wanted it when I wanted it and expected. Great work and awesome running some of the toolpaths I have run, but not as cut and dry as I think it could be, Dave C and I have many conversations about this and he has plenty of examples from me on this topic.

Share this post


Link to post
Share on other sites
10 hours ago, 5th Axis CGI said:

What I find is a little math is involved. If the depth is not in the perfect place within the depth setting you will see this behavior. By playing with depth of cut and the steep shallow I can always get it fixed. Yes a real pain, but once you understand the math behind the process you see the solution. Say you leaving .05 in the floor. Then set you depth in the steep shallow to +.05 from the deepest point. Then you need to see what your top of stock it. Lets say we are cutting 3.567 deep and we have set a depth of cut as 1.75 on a 1/2 endmill. We do the math and we have 3.567/1.75 we get 2.0382 cuts. Not all that good. If we do the math the other way and take 3.567 and divide by 2 we get 1.7835 for a depth of cut. Now we will see we get a nice process, unless we are dealing with different depths. Then all bets are off. I will then sometimes have to go back and do a section at a certain depth. I will copy the operation and create a .01 to .02 steep shallow for that missed section and now I know it gets cut to where I expected it. I wish they would change the whole process to be depth aware and logically sort the motion in ways that not only took what they have, but looked at other more practical issues. Thin webs. reduced walls and other things are not considered as part of the calculations. What mass of the section are you cutting? What is the depth to length for a thin web they are leaving and other things that I feel should be part of the math. Maybe they will get there, but mathematically I feel they are leaving a lot on the table that could be done.

I am the crazy^millman so take what I say with a grain of salt.

That was mainly the issue. I was trying to restmill this pocket area that has different ledges and 3 or 4 different depths. I just couldn't get a clean path out of it. I am just trying to use the software more rather than using lots of 2d paths like I normally will. 

Ill play with it some more , thanks. I ended up using area rest roughing in areas and I liked that path a lot better

  • Like 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

Join us!

eMastercam - your online source for all things Mastercam.

Together, we are the strongest Mastercam community on the web with over 56,000 members, and our online store offers a wide selection of training materials for all applications and skill levels.

Follow us