fluted spirals

[steve_g]

I’m using a “fluted” spiral toolpath to cut some depressions… I’ve used fluted toolpaths with great success in the past but this particular application isn’t working as desired! You can see that the interior is “textured” like it’s been hand carved. This would be great if it was what I was after! I’m looking for smooth… you can see from my screen capture of the toolpath on the spiral that the toolpath jumps all over the spiral!

Has anyone else experienced this? Has anyone developed a method of rapidly cutting smooth walled depressions, not pockets, but more bowel shaped?

http://www.talkshopbot.com/forum/attachment.php?attachmentid=30398&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=30399&stc=1

SG

[dlcw]

The only thing I can think of is to check to see if your vectors are all smooth and not small straight lines. Use Node editing to make sure everything is smooth (Blue nodes, not black nodes). I'm not a strong 3D guy so I'm just throwing out what has bitten me in the booty before.

[scottp55]

Steve,
Was that using the Spiral Gadget with an Archimede's spiral?
Can you try more wraps with the preview turned to Max....Think I ran across the same problem using VCP7 though..and wound up using circular array with a .5BN, but it was tricky getting it to toolpath the first 2 flutes (alternating start points) with a pass depth, and then arraying those 2 for full depth passes and having it not jump around so that I was taking off only at a time like on a 3D.
Last few I've done with VCP8 are all 3D rasters with the biggest BN I have.
Think I did it with the Spiral Gadget once for a golf ball size for someone else, but going to have to jog my brain in the morning and see if I can find the e-mail.
scott

[steve_g]

Scott…

I tried various methods of constructing the spirals including using the gadget. Also, it doesn’t seem to make any difference whether the nodes are Bezier or line segments. It’s interesting to me that the tool paths seem to bounce around without regard to the nodes!

This method of cutting domes sure beats 3D time wise… I can cut a 6” dia. Dome 1.5” deep in just a few min., just wish it was not so textured!

SG

[dmidkiff]

Scott,

I don't have any experience with the methods you are describing. Is there a choice to cut along vector? I'm sure you would have tried if the option was there but just in case you overlooked.

[scottp55]

Hey David,
No options on the fluting toolpath...it's always a profile on line cut.

I should have figured Steve had tried everything and that it was my memory at fault.
I probably wound up sending Jeff a fluted circular array for his golf ball holders:(
Funny though, that a 60wrap wound up smoother than a 100wrap in that 6X1.5" example Steve gave, and that curve fitting vectors didn't seem to make any improvement.
Probably a good one to send Vectric and ask why it's NOT following the vector.

Steve...Haven't done it myself, but a bunch of threads on the Vectric forum on how to use the Moulding toolpath to make custom bowl shapes(one half at a time?)
Got to stop playing and go finish fixing my Mom's antique table that's been fixed 3 times before I even saw it...PITA fixing other peoples repairs.
Sorry Steve:(

[steve_g]

Molding toolpaths can get flaky if you’re not symmetrical… it works great for scooping chair seats, but I had issues when I tried ovals and kidney bean shapes… in theory, the fluting toolpath should be the perfect solution. The fact is, I’m using it in a manner not originally intended!

To find what the limits are, I’ve determined that it’s not the length or the number or type of nodes that is the limiting factor. It seems that when my spiral exceeds about 15 revolutions, things go haywire.

SG

[scottp55]

I think you're right Steve:)
After playing some more with a 20 wrap, I think that's how I got Jeff's golf ball depression close enough.
Still it's way odd that the bit won't follow a vector on the line though:(
I looked back at my 2015 spiral/fluting putzing, and it's the same way.
Good question for Vectric or their forum.
Thanks for the practice and insight!
scott