*** MOLD TRUE ***

[Bob La Londe]

Its a work around.

https://youtu.be/H3JEdhoX9Hw

[lloydsp]

Yeah, "useful to some of (us) guys"!

Thanks, Bob.  That method never occurred to me.  I've always only created 'molds' in 3D in the negative in my CAD.  Fortunately, I've always been the guy creating the molds.  But I can see where that would be very useful, whether receiving mold concepts from customers, or from published files of solids.

That's a neat technique, even if it is just a "work-around".

Lloyd

[EddyCurrent]

Bob,
Good idea inverting the faces.

You mentioned not being able to generate a silhouette at a desired level, you already have the plugin installed, Edit->Surface->1 slice

[Bob La Londe]

Bob,
Good idea inverting the faces.

You mentioned not being able to generate a silhouette at a desired level, you already have the plugin installed, Edit->Surface->1 slice

Well dang it.  I never even tried that function before.  Thank you.  I actually noticed a couple other things too when I reviewed the video.  I'm tempted to redo it, but I hate to spend a lot of time on those one shot idea/help videos.  You might notice I didn't even put in title or follow up credits pages.  I like to just wing it until it works like somebody who is learning how to do it might. 

[EddyCurrent]

Thinking about though it will not be a true silhoutte because it will take on the contour of where it was sliced, whereas a silhouette is like a shadow cast from the largest outline of the surface.

[Bob La Londe]

Thinking about though it will not be a true silhoutte because it will take on the contour of where it was sliced, whereas a silhouette is like a shadow cast from the largest outline of the surface.

Sometimes I need a slice at a particular level, but its a good point. 

[pixelmaker]

hello
I'm reading this carefully, but I don't understand the problem.
I'm loading a 3D object into CB V1 R16.
I am creating a 3D profile tool path.
I switch to mold true.
I'm using a distance to the boundary that is larger than the tool to get a border.
I get a proper toolpath
If I want to start the milling at Z=0 then I move the toolpath with the transformations matrix

Look at this video and please explain the problems.
https://www.screencast.com/t/PwbgmcT5k

ralf

[Bob La Londe]

I looked at your video and it appears to work.  I'll have to duplicate it first, but I have not been able to get MOLD = TRUE to work in some time, and when I asked about it I was told the function was broken.  

Mold True has always had some inherent problems even when I was able to get it to work.  Including the flip and transformation requirements.  The biggest issue has always been positioning the actual cavities to actually create a two piece mold.  I know "it can be done", but its not just about the mold cavity.  Its about vents, pins, screws gates runners sprues and everything else required to make a real mold.  That why I changed over to using negative models.  I can put them EXACTLY where I want them and I don't have to adjust, flip, transform. or tweak anything.  They cut where they are supposed to.  

Apparently the function is not broken according to your video or you are using an older version to use that function.  I have used it years in the past, but when I tried to use it in recent years it didn't produce anything useful.  I came on this forum and asked a few questions a year or so ago (give or take) and got nowhere.  I assumed that the function was broken or "still" broken, and looked for other solutions.  

While I'm not sure its a magical cure to all that ails, but the invert faces solution is simpler and requires no transformations, no tweaking to locate accurately, and no adjusting.  It just works right where you put it in the orientation.  That means when you mirror it (or rotate it) everything will line up accurately with no adjustment.  Pins, screws, gates, runners, vents will also all relate directly to the cavity cut.  It just cuts where you put it.  Everything in both halves of a mold will line up without having to tinker with anything. 

Is there a problem?  Apparently I was wrong about one thing.  You obviously are able to get the Mold True function to work.  Yes, but is there a problem?  Well I always thought so.  I think the Mold True functions is cludgey and backwards and makes it difficult to get everything where you want it and in accurate relationships with each other.  Even back when I was able to get it to work.  

[dh42]

Hello

At least there is this problem that remain with mold

http://www.cambam.co.uk/forum/index.php?topic=7916.msg63574#msg63574

this bug is also in 0.98

++
David

[Bob La Londe]

Ultimately though my video was not "OH WAH!  Boo Hoo Hoo!  Sob!  Sniffle!  I can't do this."  It was, "YEAH!  I found a way to do this!!!"

[Bob La Londe]

I spent a little time experimenting yesterday with the mold true function and the new invert faces work around. 

First off, I am not sure I ever really understood how the Mold = True parameter worked and what it did before. 

I was able to get the Mold = True parameter to work... sometimes. 

I was also only able to get the invert faces method  to work sometimes. 

They both seemed to fail to produce tool paths under quite a number of conditions.  Particularly when trying to restrict tool paths by various methods. 

[EddyCurrent]

Ralph,

Can you attach a cb file you used in the video ? "screencast" needs Flash Player installed but I don't have that and won't be having it.

[pixelmaker]

I haven't worked with the Mold function lately and had already forgotten the bug.

It seems that the error could be corrected by entering a roughing clearance of 1/2 tool diameter and moving the toolpath to1/2 tool diameter -Z by the same value. But first I would have to test this extensively and I don't have much time at the moment.

I create my molds in the 3D software

ralf