[V1 - 22] Backface milling in 3D MOP no longer works (solved in V1 RC1)

[dh42]

Hello

It seems that the Backface milling is no longer working in V1.0 (tested on R16)

Also, even in the previous version (0.98P), backface milling works only with the top of the object at Z=0 ; if we works with the bottom at Z=0, the toolpaths are wrong.

++
David

[pixelmaker]

Backface milling is no longer working

http://www.cambam.co.uk/forum/index.php?topic=3658.0

This is the same heavy bug that exists since version 0.9.8.P. It never works since this.

I have just tested again and see no difference between the frontside/ backside milling of z constant toolpaths or waterline toolpaths. Nothing works.
Even if I align the top side of the object at Z=0, no toolpaths are created for the back side. All toolpaths are only from the front side.
I've been used to turning the object around since 0.9.8P, so it didn't occur to me that this has changed for the worse.

ralf

[dh42]

Hello Ralf

Yep, it's worst in 1.0 than in 0.98 ... not usable at all in 1.0

I've been used to turning the object around since 0.9.8P, so it didn't occur to me that this has changed for the worse.

Yes, not easy to remember all what must be tested on each new version !, and I rarely use 3D machining and even more rarely the back side functions for my use.

++
David

[Bob La Londe]

I had not realized this was a bug or lost feature.  I just thought I forgot how to do it.  

When I design a mold I build a positive (casting) and then use a Boolean subtract to remove it from a block to create the mold.  That is what I export from CAD to import into CamBam to do the CAM work.  

However, sometimes I get an STL file from a customer, and the only practical and efficient way to make a mold from it is with backface.  Its not a tool I use very often, but it is an important tool.  Sometimes its the only practical and efficient way to do the job.  

[Bob La Londe]

What was the last release where it worked properly? 

[dh42]

Hello

I don't know ; on 0.98 P it works only in certain cases (depending of the Z position of the object) ... I don't remember if it has worked properly on older versions.

++
David

[pixelmaker]

I don't know ; on 0.98 P it works only in certain cases

0.9.8P works fine for me.
Both if the objects are centered in Z-direction as well as top and bottom. Then you only have to set the mirror plane with "Backside Z 0".
I did not install the old versions 1 anymore.

ralf

[EddyCurrent]

To avoid possible confusion and /or errors I would rather rotate the object myself and create a MOp for it as normal.

[Dragonfly]

Some models might have a flat bottom and rotation will not work.

[pixelmaker]

I think it's the same whether I rotate a toolpath around an axis at a certain Z-height or whether I rotate an object.
With back side milling in CamBam, only possible up to 0.9.8P, also only one pivot point is calculated.
The disadvantage is that you have to have the 3D object twice in the file if you want to archive it.

ralf