Speed/feed for 3d cutting of corian with tapered ball nose end mill

[Chuck Keysor]

Holiday greetings fellow Shopbotters!

I am almost done designing a 3.5" diameter Tudor Rose in Aspire which I am going to cut out of white 1/2inch Corian. I plan to do the 3d roughing pass with an Amana 1/4" flat endmill, and the 3d finishing pass with an Amana 1/16th diameter tapered ball nose end mill.

I did a site search looking for speeds and feeds for Corian, and I didn't find any info that pertained to my situation. And I have never cut Corian before. I understand it carves very well, which is why I am using it.

Should I limit my 3d finishing pass depth to 1/32", (using 8% step-over)? Or is Corian so soft that I can go more aggressively? And since this is a tapered ball nose end-mill, doesn't that allow me to consider the bit as being fatter than a straight 1/16th endmill?


I don't want to mess this up by trial and error, because Christmas is coming, and I have to be done several days before Christmas.... And I don't want to risk busting my expensive tapered ball nose end mill by rushing things..

Your suggestions will be appreciated! Thanks and Merry Christmas, Chuck

[Kyle Stapleton]

Corian cuts well but it is hard, for profiling and pocketing we use a 1/4" up cut and o flute, 1/8" up cut, and 1/16" o flute bits and all cut well just need to go slow and take your time.
With the bits feeds and speeds are:
1/4" 2-3 ips @ .125-.25 @ 12000-14000 rpm
1/8" 1-2 ips @ .0625-.125 @ 12000-16000 rpm
1/16" .5 ips @ .003 @ 16000 rpm

This I just what we have found works well, no chip load just by ear and looks.:eek:

[Chuck Keysor]

Thanks Kyle! I appreciate your quick reply! I recently bought some Amana spiral O flute end mills for cutting aluminum, which I haven't gotten to, so these bits are brand new.

I have attached the screen shot of the Tudor Rose that I just got done creating in Aspire. I suppose it could use some fixing up. I was looking at line drawings of Tudor Roses on the Internet, and there are so many, good mixed with the bad,,,, I should have looked more carefully, and found the best looking example. Instead, I looked for one that was nice, but also one that looked easy to layout. Easy was important, since I hadn't made any "3d" models in Aspire since late this spring. But thankfully Aspire is much easier to dust off and get working with then Illustrator!

Thanks again and Merry Christmas, Chuck!

[Chuck Keysor]

PS: Kyle, while I don't plan to use it on this project, I have a couple of Amana 1/32" dia. tapered ball nose end mills. What speed and feed do you recommend for that bit when cutting Corian?

I have a Shopbot notebook, where I write these things down, so it is worth asking now, so I will be able to find all of my Corian cutting notes all on the same page.

Thanks again, Chuck

[Kyle Stapleton]

Look up Brady he has use some very small bits. He has some post in the desktop area about little bits.

[Chuck Keysor]

Yikes! My Aspire simulations of adding V-carved details to my Tudor Rose, shows I have a real problem, and I don't know what to do. Any suggestions? Thanks for any help you can provide.

Attached are two images from Aspire for my Tudor Rose. The first image shows that I selected my 3d model and a series of little circles and radial lines that I wanted to V-carve onto the surface of my Tudor Rose in order to add some needed detail. I was going to use a 60 degree CMT "laser point" bit for the v-carving.

The second image shows how this simulated, and it looks bad! I am getting gauged/hacked marks, instead of nice sharp lines. (We have all seen repeated warnings to NOT ignore ugly looking things in the simulations!)

The first simulation (not pictured) I did of projecting the little circles onto the center of the Tudor Rose turned out fine. But when I added the radial lines, to define the edges of the petals, that is when things went bad, and that is what is shown in the second image.

I model is set up to run the simulation at 7X resolution. I need to add these details. I haven't been able to figure out how to fix this, except to manually scribe the lines in instead of V-Carving them.....

Thanks, Chuck

[Kyle Stapleton]

Not sure about the v carving but try using a raster and not the offset for your 3d work and bring you step over down to 3% and see what happens.

[Chuck Keysor]

Thanks Kyle. I ran the 3D finish with a raster strategy at 3%, and the work was cleaned up a little bit. But the machine time of course went up, and is now almost 5 hours.

Most importantly, I tried the simulated V-carving with the raster carved Tudor Rose, and the V-carving turned out just as badly as before when I carved the radial lines.

Any ideas???? Thanks, Chuck

[MogulTx]

Chuck,

What if you were to reverse the petal separations and make them convex? It would make them seem like the edges of the petals were curled up, and would give you the separation between petals. And you might just include them in the 3D carving.

Alternately can you take the 3D profile of the petal separation and run a 2 rail sweep ONLY for the separation line? ( you would have to have some modest separation there. For example, offset a line .01 to one side and .01 to the other so that there is a total separation of .02. Select a concave cut and select the two lines to use as your 2 rails along which to sweep... That is probably what would yield a very fine, very well detailed and neat line for you- and it would have a selectable shape of your choosing...

[Joe Porter]

Chuck, I can't quite see from you first picture, but are your V-Carve radial lines closed on each end? V-Carve must have a closed vector to work properly....hope this is of some help...joe

[Chuck Keysor]

Thanks for the added replies. Joe, the shapes I used for the v-carving were closed, with the long sides being straight lines, and the ends were arcs.

I did do a quick test with using two rail sweeps to form my fine lines, but no lines appeared no matter how I experimented with the merge modes and base heights, etc. I think I was getting frantic knowing I'd have to set this aside until after Christmas.

So now I have to get to work on Christmas preparations and set this project aside for the next week. But if anyone else has thoughts on this, please feel free to comment, even if I am unable to reply for awhile.

Thanks, and Merry Christmas to all! Chuck

[adrianm]

Did you have the "Project onto 3D" option checked for your VCarve toolpath?