dhellew2 wrote:
...the bit taper cuts away some of the wanted detail.
Dale
Hi Dale,
Gentle correction/explanation here. Tapered bits don't actually cut away detail portions of a 3D raster machined model, they try to avoid it - the software takes into account the bit geometry of a tapered bit to preserve the topmost detail of a model so it won't cut anything away due to the taper. It does this by LIMITING the depth a tapered bit can plunge into a raster carve crevice. (Very much like a v-carve depth is limited between vectors to preserve the topmost appearance of a vcarve job.)
Visual loss of detail can occur because the prevention of a tapered bit going down into a crevice too far - not because it is actually carving away any detail during a raster carve of a 3D model. I attached a simple illustration that may help folks visualize this. You can see the straight bit can go deeper (thus more detail can be achieved) than the tapered bit under certain circumstances (which I attempted to illustrate in the graphic).
Another simple example. Make two 1" diameter disc models. (Create an offset slightly greater than the shank diameter around each disc for this test). Raster carve one with a tapered bit and the other with a straight bit. Both discs will still be 1" diameter at the top of each. The tapered-carved one will have a WIDER diameter at the bottom. Again, this is because the software knows not to cut away the topmost portion - it assumes you want to preserve the top dimension of each disc.
Thanks guys for your comments, posted finished pics and kind words about Design and Make. Keep up the great work it's so inspiring for everyone... thanks for sharing!
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Todd Bailey | Design and Make
DesignAndMake.com
You know me, as usual I was pushing the boundary by cutting 1-1/2" deep in a single pass.
I don't really know at what depth the over cutting starts and I also know it also depends on the taper of the bit.
At 1.5" the difference is really obvious in the two examples, same wood, same finish
The two examples were cut to within 1/4" of the same depth.
Dale
You will get old if you live long enough!
Young = time, no money
Old = money, no time
Dale
So, Dale...sounds like you are correct, but for the wrong reason . So, if we want more detail on a carving deeper than the radius on the ball nose, we should use a straight bit. (I think you already said that.)
You can draw geometry around the eagle head ( like a circle ) and just re-machine that area.
That way you could machine just the head area with the 1/16" bit and perhaps save a bit of time/cutter wear.
"Rest" machining might be better yet but I don't have experience with that yet.
You can draw geometry around the eagle head ( like a circle ) and just re-machine that area.
That way you could machine just the head area with the 1/16" bit and perhaps save a bit of time/cutter wear.
"Rest" machining might be better yet but I don't have experience with that yet.
Hmm never thought of it that way great idea. Thanks for the tip and sharing it.
You can draw geometry around the eagle head ( like a circle ) and just re-machine that area.
That way you could machine just the head area with the 1/16" bit and perhaps save a bit of time/cutter wear.
"Rest" machining might be better yet but I don't have experience with that yet.
Hmm never thought of it that way great idea. Thanks for the tip and sharing it.
You can't do rest machining in Vcarve Dwayne but you can set up vector boundary's & use those for machining, not sure if you would get a seamless join between the 2 size bits though as it's not something I have tried, machined only part of models using boundary's but never tried with 2 different sized tools.
dwilli9013 wrote:
You can't do rest machining in Vcarve Dwayne but you can set up vector boundary's & use those for machining, not sure if you would get a seamless join between the 2 size bits though as it's not something I have tried, machined only part of models using boundary's but never tried with 2 different sized tools.
I have used that technique and it works like a charm! Too late for this job of course. Thanks for the reminder.
dwilli9013 wrote:
You can't do rest machining in Vcarve Dwayne but you can set up vector boundary's & use those for machining, not sure if you would get a seamless join between the 2 size bits though as it's not something I have tried, machined only part of models using boundary's but never tried with 2 different sized tools.
I have used that technique and it works like a charm! Too late for this job of course. Thanks for the reminder.
Mark
Mark, if you have machined using 2 different sized tool bits & then set up vector boundary's to machine fine detail with a smaller bit did you set the boundary's with a slight overlap to help prevent any sort of seam between the 2 ? Seems like that might be the best way to go about it but as I say it isn't something I have tried
Very interesting. I like your results. I will experiment a bit between the tapered ballnose and a straight cut. Anything that saves me sanding time saves me time overall.
Some great examples you have shown I appreciate them all.
dwilli9013 wrote:Very interesting. I like your results. I will experiment a bit between the tapered ballnose and a straight cut. Anything that saves me sanding time saves me time overall.
Some great examples you have shown I appreciate them all.
Not saving sanding time as much as saving machining time Dwayne, if you have a model that only has a small area of detail that requires a small bit you can use a larger tool for your finishing cut on the majority of the model & then finish cut just the detailed area with the smaller tool saving time over using a small tool to machine the whole model.
martin54 wrote:Mark, if you have machined using 2 different sized tool bits & then set up vector boundary's to machine fine detail with a smaller bit did you set the boundary's with a slight overlap to help prevent any sort of seam between the 2 ? Seems like that might be the best way to go about it but as I say it isn't something I have tried
Martin:
The rendering of the Kokopelli Man candle trivet a few messages up on this thread is an example of using two tools for a finishing tool path. The little guy with the flute was first cut with a 1/8" ball nose bit then again with a 1/16" tapered ball nose bit. I selected the boundary of the little men for the second finishing tool path with no offset. Worked great!
I think you could select a random boundary around a portion of a large carving like the eagle's head and this technique would work. Maybe a little blending with a small wheel sander would help. Perhaps Todd Bailey could add to this...
I think you could select a random boundary around a portion of a large carving like the eagle's head and this technique would work
It does Mark, before I had Aspire I use to draw Vector boundary's to isolate portions of Models when I didn't want to carve the whole thing, in fact if you have a look at this post I showed Highpockets how He could use it to machine a rope border at a narrower width than the model produced at the length he needed