Page 1 of 1

Do you ever lie to Vcarve?

Posted: Wed Aug 30, 2017 5:34 pm
by johnelle
I am turning out a bunch of small pieces and have found matching the tooling with what I want to do a real challenge. One of the things that really peeved me was when Vcarve grayed out a tool that I was pretty sure would work fine.

As I was reaching a hypnotic state watching the carving bit go over and over some details, an evil thought popped into my head. I wonder if folks routinely let the software do its CAM thing with a certain tool defined but then actually load a different tool. For example telling it you are using a sharp engraving bit but then actually loading a small ball nose instead.

I would experiment with it but I am in the middle of production.

So is this just common practice amongst the seasoned CNC'rs or is it just an evil thought that I should drop?

Re: Do you ever lie to Vcarve?

Posted: Wed Aug 30, 2017 5:46 pm
by Bob Reda
I do it, also if you use the keyhole gadget you will lie telling it is an endmill when you are using a keyhole bit.
Bob

Re: Do you ever lie to Vcarve?

Posted: Wed Aug 30, 2017 11:49 pm
by 4DThinker
You have to "lie" when using any router bit that does an undercut, as vectrics' products can't preview what the real result of their use will look like. T-slot cutters and Dovetail bits usually. Occasionally a big ball end on a small shank. I also am fibbing to the software when I create toolpaths for what looks like a normal flat rectangle of wood but is actually the end of a chair or table stretcher clamped at a compound angle under my CNC. I'm guessing this isn't what most folks do with their CNCs, but it is a fairly common occurrence in the fine furniture workshop at the university I teach at.

4D

Re: Do you ever lie to Vcarve?

Posted: Thu Aug 31, 2017 1:22 am
by IslaWW
"Do you ever lie to VCarve?"

Of course, it's software. Software is made to be tricked, hardware is made to be modified. Not the other way around.

Re: Do you ever lie to Vcarve?

Posted: Thu Aug 31, 2017 1:22 am
by Leo
I don't really think of it as lying.

Using the tool within it's capabilities to gain a desired result, is more appropriate.

Really, all a CNC program is even doing it describing a path from one point in space to another point in space. Everything else is just getting dragged along for the ride.

Tool shapes, no matter what the shape is - is really just going along for the ride.

Now - "GRAPHICALLY" - we "want" to see something else and Vectric draws in all the graphical stuff so we can more easily "see" what we want to see. They do a GREAT job at it, but there are limitations.

Soo - given the limitations - we can improvise a little to get the toolpath, but also understand the limitations but also "see" with our minds eye - what we want to achieve.

WHEW - I dunno if anybody actually read that, but me thinks, maybe it's bed time for me.

Re: Do you ever lie to Vcarve?

Posted: Thu Aug 31, 2017 2:04 am
by scottp55
I lie about the angle and flat on engraving bits all the time to get the effect I want if needed.
Does take a little playing around, as the preview will be wrong of course, and you have to actually cut, to see what you've got.
Play with small projects before production.
In buttons pic...it was the same exact toolpath and and 60 degree bit with .02" flat, but I changed to 30 degree on top row, and then fussed with tip width until I got what I wanted.
On burnt Maple pics , you can see I wanted more white area for contrast, so called the 60 a 30 degree, and you can see how on the right side it narrowed down the surface too much.
Takes a bit of playing, to get an idea of how it will actually cut.
When I used Cut3D, I made up imaginary TINY ballnose bits with tip size that matched engraving bit flat because it wouldn't let me use an engraving bit, and used 30 degree engraving bits for Tiny stuff, but not the other way around.
scott

Re: Do you ever lie to Vcarve?

Posted: Thu Aug 31, 2017 2:46 am
by IslaWW
Listen to Leo: "Tool shapes, no matter what the shape is - is really just going along for the ride."

Truer words were never spoken. We get caught up in the pseudo details of how to do all these toolpaths by the numbers, tool descriptions, form tools ad infinitem. I like to see what action a particular type of toolpath delivers. Of course the 2.5D are my favorites as they can do so many things. The VCarve toolpath has a fairly rigid set of rules, but the others.. no limits!

Learn to look over and understand the wireframe toolpath view and you will learn a lot. You will see what the center bottom of the bit does, that how they are calculated. You can use that info along with some basic knowledge about bit shapes in material to expand your horizons. Personally, I do not use the toolpath preview for my daily work. In fact, if I didn't use it to prep training slides I would never have had a need for it. I learned on the wireframe and use it still today. Especially for rotary. I also realize this is not typical.

Re: Do you ever lie to Vcarve?

Posted: Thu Aug 31, 2017 11:48 pm
by Fleming
I lie quite often when using V bits to do text, especially small text in wood that tends to splinter out. I spec a 60 degree bit and then cut with a 30 degree bit. This leaves the boundaries between letters a little larger and the letters such as an "o" a little fatter within thus getting a cleaner cut. What you sacrifice is the sharpness of corners but for small text your eyes don't typically see that.