Check Surfaces ?

General MeshCAM Questions

Check Surfaces ?

Postby larynx » Tue Jun 07, 2016 10:38 pm

So I have read a few items on them, searched the forums and web. Can someone explain what they are required to be - "dxf" I have seen somewhere and "stl" in another. I know they must be imported on the "area to machine/exclude" menu - I have done a few "dxf" exports and tried to import them - they import I think but I do not see them on the model as excluded. Do they need to be a special mesh or what?

I have a few cuts that require more than one tool - I am manually changing - and would like to use them as excludes/only machines to be more exacting.

I believe this would be a good sticky topic for everyone if it was explained.
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
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Re: Check Surfaces ?

Postby Randy » Wed Jun 08, 2016 5:13 am

Check surfaces and machine regions are two different things.

A check surface is a second STL that you add to an already-loaded geometry. It is a "floor" that the toolpaths will not pass, but MeshCAM will machine down to the check surface.

A machine region is a boundary drawn by hand, or imported as a DXF, on the top surface of the stock, and MeshCAM will only make toolpaths within the boundary of the machine region. Conversely, a keepout region is an area that MeshCAM will not make toolpaths inside.

Here is an STL, part of a model diesel locomotive shell.

geometry.PNG
geometry.PNG (95.85 KiB) Viewed 1049 times

Here I have drawn a machine region over the front end of the shell.

geometry with machine region.PNG
geometry with machine region.PNG (127.09 KiB) Viewed 1049 times

And the toopaths that stay within the machine region, but all the way to the max depth (the bottom of the geometry in this case)

toolpaths with machine region.PNG
toolpaths with machine region.PNG (114.93 KiB) Viewed 1049 times

Here is the geometry again, but with a check surface (in red) that I loaded

geometry with check surface.PNG
geometry with check surface.PNG (114.36 KiB) Viewed 1049 times

Check surfaces don't need to be level at all--they could be as involved as the geometry itself. In this case, the geometry had an undercut on the sides, and it would be wasteful to machine down past it. But the nose doesn't have the undercut, so I wanted to machine it all the way down.

toolpaths with check surface.PNG
toolpaths with check surface.PNG (107.99 KiB) Viewed 1049 times

You can also use check surfaces along with machine regions.

toolpath with check surface and machine region.PNG
toolpath with check surface and machine region.PNG (110.98 KiB) Viewed 1049 times

And of course, you can also use max depth, angle limits, etc. to really constrain where you generate toolpaths.

I hope this helps.

Randy
All opinions in this post are mine alone. I am not a MeshCAM employee, I do not have a financial interest in MeshCAM, nor do I speak for MeshCAM. MeshCAM user since Beta 5 in 2003. viewtopic.php?f=11&t=15333 :ugeek:
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Re: Check Surfaces ?

Postby larynx » Wed Jun 15, 2016 9:20 pm

Thanks again Randy. This should be a sticky. I know I saw somewhere they were spoken of, they were dxfs, they were only flat surfaces, used for excludes, the time I did see them. This is extremely helpful and I thank you once again for expounding on the possible uses and application of them.

Perhaps, if you can sticky this, you should delete my question and reply, only placing in the thread your or other responses and explanations others might find useful.
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
Posts: 64
Joined: Thu Oct 29, 2015 2:56 am
Location: East Central Florida

Re: Check Surfaces ?

Postby Randy » Thu Jun 16, 2016 9:18 pm

I'll do some digging on how to set up a "sticky" section of informative posts--I'm really not familiar with this forum software at all. There are some questions that keep coming up periodically, and I even need to go back and search to find the previous explanations. Thank you for the suggestion, and I'll see how well I can implement it. :)

Randy
All opinions in this post are mine alone. I am not a MeshCAM employee, I do not have a financial interest in MeshCAM, nor do I speak for MeshCAM. MeshCAM user since Beta 5 in 2003. viewtopic.php?f=11&t=15333 :ugeek:
Randy
 
Posts: 1812
Joined: Wed May 14, 2008 9:50 am
Location: North Texas, USA

Re: Check Surfaces ?

Postby larynx » Fri Jun 17, 2016 7:50 pm

Randy,

I do not see how you get any of your own work completed :twisted:

You spend all of your time helping us. Perhaps you should just post your telephone number :o

Seriously, thanks again.
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
Posts: 64
Joined: Thu Oct 29, 2015 2:56 am
Location: East Central Florida

Re: Check Surfaces ?

Postby Randy » Fri Jun 17, 2016 8:00 pm

You are very welcome, larynx! And thank you for the kind words. It is my pleasure. And much of what I know about MeshCAM does come from researching and answering questions. In the long run, it does help my own projects too.

Randy
All opinions in this post are mine alone. I am not a MeshCAM employee, I do not have a financial interest in MeshCAM, nor do I speak for MeshCAM. MeshCAM user since Beta 5 in 2003. viewtopic.php?f=11&t=15333 :ugeek:
Randy
 
Posts: 1812
Joined: Wed May 14, 2008 9:50 am
Location: North Texas, USA

Re: Check Surfaces ?

Postby larynx » Wed Jun 29, 2016 5:35 pm

Ok, and hello Randy.........

First I should state, now that I get it [somewhat apparently, and only somewhat] I have successfully applied dxf check surfaces, until this one and it is simpler than a few others.

Basically, after my miter now being cantankerous, that great [until a couple of days ago] saw, slicing a piece of wood at a ~10degree slot cut, I decided, hey.....use the CNC......and then I got to here......

This CNC cut is only a simple slot cut. It divides a piece of wood in two leaving the same angle on both sides. Nothing complicated, just back and forth aligned in the x-axis so the gantry travels back and forth....simple.

I decided to use a DXF include file for the cut, then found that even though I stipulated NO extra Material, use the roughing cut only with low stepdown [0.025"] values and NO extra stock to leave, with no allowances, just cutting the slot appears to leave the confines of the dxf include. So, I added a dxf exclude. Still the cutter center-line appears to leave the slot once clear of the "block" underneath STILL WITHIN the exclude area ???????

STL, Includes/Excludes submitted as "SET 014.zip"

Images below of setup and result in MeshCAM, last one is Rhino with the solid depicted and the include [green] and exclude [red] surfaces MOVED to the side just to show the regions clearly.

I must be caught in another Bermuda Triangle........

On a side note, when I went to cut the wood on the miter saw, the blade lost a couple teeth [?] and screwed up the cut. I fixed that, moved on to the CNC, my X-axis motor coupler shot itself [how does that happen, I don't know, everything is aligned, lubed, moves with two fingers, I was not even cutting anything yet].....fixed that [had to pull the screw to get to it], then fired back up and the computer crapped out.....new drive....reload software, made it to the NEXT day.....

So you see where I am going? FYI, all new equipment within the last year. I won't mention the lighting strike and two-tree fire twenty-feet from the house I had to put out the day before.....ah, I just did.....If God was the burning bush I guess I just put out all hope......
Attachments
slot diagram 2.jpg
slot diagram 2.jpg (229.61 KiB) Viewed 972 times
slot diagram.jpg
slot diagram.jpg (36.27 KiB) Viewed 972 times
SET 014.zip
(4.2 KiB) Downloaded 50 times
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
Posts: 64
Joined: Thu Oct 29, 2015 2:56 am
Location: East Central Florida

Re: Check Surfaces ?

Postby Randy » Thu Jun 30, 2016 6:44 pm

larynx, I don't have a quick answer for this. I'll need to do some experimentation with your files and probably some others. I have a feeling that it should require either an include or exclude area but not both, if the other parameters cooperate. I think it's a matter of finding the right combination of parameters which might take a little time.

Randy
All opinions in this post are mine alone. I am not a MeshCAM employee, I do not have a financial interest in MeshCAM, nor do I speak for MeshCAM. MeshCAM user since Beta 5 in 2003. viewtopic.php?f=11&t=15333 :ugeek:
Randy
 
Posts: 1812
Joined: Wed May 14, 2008 9:50 am
Location: North Texas, USA

Re: Check Surfaces ?

Postby larynx » Sun Jul 03, 2016 12:28 pm

Randy,

Changed the include to a rectangle rather than cut [triangulated] ends and it worked. I can use include and exclude together, am doing so in another iteration. Don't bother if there is no quick answer, someday when you discover something we may like to know about then please let us know. Otherwise, there is a workaround available and I have since the first post changed the shapes or used curve networks in Rhino to generate the include/exclude surfaces rather than loft and am much more successful doing so - not sure why but MeshCAM seems to have a problem reading some loft surfaces, but so far not any curve network surfaces exported to AutoCAD 12 Natural dxfs - my experience. I also had a few problems with Surfaces exported using the earlier versions of AutoCAD from Rhino 5, but they worked once exported as 12 Naturals. Maybe it is me, but that is what I am finding on my end.
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
Posts: 64
Joined: Thu Oct 29, 2015 2:56 am
Location: East Central Florida

Re: Check Surfaces ? New Issue with Loading DXFs

Postby larynx » Thu Aug 04, 2016 10:59 pm

Curious, does anyone else have this issue - which there is a long answer for - other than me? Has anyone found a better solution?

When I load an STL, then a check surface DXF, Meshcam works - on the FIRST STL.

If I then attempt to load a different STL file, and it's related DXF check surface, I get load errors for the "not found" related to the DXF loader.

If I close Meshcam, reopen and then load the file again with its related check surface - everything works.

So it appears it is losing the reference either to the location of the loader or just hanging.

Again, close and reopen, everything is fine. Windows 7 64bit, MeshCAM 64 bit latest build.
I am not aligned with nor do I have any relationship with MeshCAM or its staff other than being a user [that sounds a little like I have a dependency problem]
larynx
 
Posts: 64
Joined: Thu Oct 29, 2015 2:56 am
Location: East Central Florida

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