Using the difference function ?

[Ken_Shea]

Now that it has been explained how to and how easy it is to wrap text around a arc or circle with OneCNCxp it brings me to another?.

While the "Model>Operations>Difference" function seems to complete when using it on text that is turned into a solid I cannot seem to get it to remove this text from the surrounding material so that it appears that the text shape is only a hole it still appears to be a surface when rendering. The text was extruded the thickness of the plate also verifying that it is a solid.

any ideas?

Thanks
Ken

"Resident oneCNC idiot"

[wms]

Ken,

The trick here is to make sure that:

1) you only have one copy of each solid
2) Only select two solids at one time to difference
3) select the solid you want to keep first and the "cutter" second.

So here we go. If you have a large square solid and your extruded surfaces (letters) then you would make sure nothing is selected to start with. Next click on the operations button, and then the difference button. Then move you curser around until the large square turns RED , and left click.
If you will notice, before you left click, at the bottom of the screen in the info box it says "select the object you want to modify". That's the large square.
Then it will say"select the object you want to remove". This will be the individual extruded letters. So select one of them. One is probably already RED , but you can select any of them. Then left click and it will remove it from the large square. Leaving a gapping hole. JK

Before going to the next one, do a render to see your handy work. Here is were you puff your chest out and think "man am I good" do a little dance, call everybody in to see how smart you are, ect...

Then come back to earth and remove the rest of the letters.


And please change your sig as no one here is an Idiot.

[HuFlungDung]

Cool! You know, I have never used the difference function yet. I've been stuck on "Solid cutter", but now I think I realize that Solid cutter may often take more "cleanup time" than using the difference function, since I do have to go and delete the cutter afterwards.

Have I missed any other nuances of the best time and place to use one or the other?

[Ken_Shea]

Ward I have done that 30 times and it will not work although when I created a new drawing similar to yours it worked fine. I have saved the drawings like you mentioned some time back so tomorrow when my old brain is fresher I will back up a few versions and maybe see what is going wrong.

Thanks much
Ken

[Ken_Shea]

Hu I can say this, the Difference is very useful when you want to say put a shaft bore through stock, a keyway, valley or just holes as well as many other things.

Ken

[wms]

Ken,
E-mail me the file and I'll see if I can spot the problem.

HU,
I use the difference function more than the solid cutter.

The difference is best when you have one solid you want to remove from another.

The solid cutter works good when you want to trim a solid with just a surface.

I've gotten in the habit of building everything out of solids.
Because it is so easy to do in Onecnc. But sometimes you have to use a surface.

[HuFlungDung]

Ward, so you're saying that a "solid cutter" does not have to be a solid, but could merely be a single surface used to cut another solid? I was labouring under the impression that the cutter has to be a solid ( I read the help )

I just tried it, and indeed a surface will cut a solid. Well, I'll be! The "helptease" never told me that!

[wms]

Hu,

Maybe we should all get together several times a year, say in the Tropics, to have a Onecnc convention. We could swap war stories and tips. Have a few cool ones and look over the native scenery.

[HuFlungDung]

That sounds like a "machinist's convention", a totally tax deductible expense! Yup, we've got to go somewhere warm and sunny to get trained in this stuff, that's for sure.

Look how happy that makes my banana!

[wms]

Ken,
You had two copies of the letters. So when you extrude the surface, it extrudes one, not the other. Then when you difference the letters from the plate, it actually does it but because there were two surfaces, the secound one "covers the opening so it looks like it didn't work. (sorry I should have put some periods in that but it's late)

I'm e-mailing you back the file with the duplicate surfaces removed.

[Ken_Shea]

Maybe tomorrow Ward (well I guess actually it is today!) how did you determine I had the two surfaces?

It worked out exactly as you said it would now.

Thanks
Ken

[Kingkong]

Originally posted by Ken_Shea Maybe tomorrow Ward (well I guess actually it is today!) how did you determine I had the two surfaces?

Hi Ken,
just mark one letter and click on 'invisible'. If there is still a letter, there were two in the beginning.

One of the most frequently 'mistake' in CAD is, to have double entities. Some CAD-Progs have a special 'Cleanup-function' for that. But I never saw a really good help from that.

The lesson for today: whenever you are in trouble with a CAD-model, look for double entities, because you can never be sure, what entity you are clicking on.