Problem with smoothing out a vector

[RA-Bowtie]

G'day guys,

I've got a problem with a vector that I just can't seem to smooth out properly.

I've tried all the usual stuff... fit curves to vectors...but not having any luck.

When I machine this vector (in Aluminium) it ends up having a whole series of flat spots.

I'm not that experienced and I would really appreciate if someone could fix this for me.

I've attached the file and made a note, so as to identify the problem area.


Michael

[Roly]

I may be wrong but if you go into the node editing mode and remove all the points in the problem area and turn that section of the line into a bezier curve, you should be able to manipulate it by the handles to get a nice smooth curve. Worked for me so I hope it helps you. Of course someone else may come in with a much simpler or better method which will give you a good choice.

All the best of the season to everyone on the forum from Roly, in Batlow.

[RA-Bowtie]

I may be wrong but if you go into the node editing mode and remove all the points in the problem area and turn that section of the line into a bezier curve, you should be able to manipulate it by the handles to get a nice smooth curve. Worked for me so I hope it helps you. Of course someone else may come in with a much simpler or better method which will give you a good choice.

All the best of the season to everyone on the forum from Roly, in Batlow.

Hi Roly,

I tried that

Well, at least to the best of my (limited) ability

Michael

[Adrian]

Fit Curves to Vectors is working ok for me. What sort of tolerance are you using etc? I'm using 0.05mm tolerance and beziers.

There shouldn't be an issue with the nodes the way they are though. Are you using a post processor that handles arcs?

[RA-Bowtie]

Fit Curves to Vectors is working ok for me. What sort of tolerance are you using etc? I'm using 0.05mm tolerance and beziers.

There shouldn't be an issue with the nodes the way they are though. Are you using a post processor that handles arcs?

Hi Adrian,

I had the tolerance set at .10

I'll give it a try on the machine tomorrow and let you know.

I'm pretty sure the post-processor is ok, as the other areas that have curves (around the holes) are fine....

Thanks for the help, I really appreciate it.

Michael

[Leo]

Looking at the CRV file, and at the nodes - nothing is going to make a smoother vector. I am really fussy about the number of nodes used and I would reduce the number of nodes in there, BUT, it would not change anything in regards to making a smoother curve.

Personally, I would look closer at the machine, holdown, cutter, speed and feed. Something else is going on, it's not a smooth vector issue.

[Timvmax]

Are you using Mach 3? If so you may need to change Exact Stop to Constant velocity

[SteveNelson46]

I know this is obvious but it isn't mentioned above. In the "Fit Curves to Vectors" dialogue box did you try using bezier curves instead of arcs?

[RA-Bowtie]

Looking at the CRV file, and at the nodes - nothing is going to make a smoother vector. I am really fussy about the number of nodes used and I would reduce the number of nodes in there, BUT, it would not change anything in regards to making a smoother curve.

Personally, I would look closer at the machine, holdown, cutter, speed and feed. Something else is going on, it's not a smooth vector issue.

Hi Leo,

The area that I'm talking about, is the only part of the vector that I'm having a problem.... the rest looks great!
Even around the 2 bolt holes, is as smooth as silk.

The piece of material is 6061 Aluminium (20.00 thick) and it's held in a vice.
I've spent nearly 2 weeks trying to figure this problem out.
I have checked the backlash on the machine, I've tried several different combinations of feeds and speeds, I've tried Carbide and HSS and they all come out with the same finish.
As you've suggested, I'll reduce the number of nodes and see if that helps.

Michael

[RA-Bowtie]

Are you using Mach 3? If so you may need to change Exact Stop to Constant velocity

The machine is a Tormach and the controller is using their Path Pilot software.

I've never seen this problem before.... but to be fair, I've never machined a vector like this before.

Michael

[RA-Bowtie]

I know this is obvious but it isn't mentioned above. In the "Fit Curves to Vectors" dialogue box did you try using bezier curves instead of arcs?

Hi Steve,

To be 100% honest, I may have stuffed up and used the "arcs" option... I'm going to re-run the part again today, but try it with the Bezier curve, option.

Michael

[Leo]

Looking at the CRV file, and at the nodes - nothing is going to make a smoother vector. I am really fussy about the number of nodes used and I would reduce the number of nodes in there, BUT, it would not change anything in regards to making a smoother curve.

Personally, I would look closer at the machine, holdown, cutter, speed and feed. Something else is going on, it's not a smooth vector issue.

Hi Leo,

The area that I'm talking about, is the only part of the vector that I'm having a problem.... the rest looks great!
Even around the 2 bolt holes, is as smooth as silk.

The piece of material is 6061 Aluminium (20.00 thick) and it's held in a vice.
I've spent nearly 2 weeks trying to figure this problem out.
I have checked the backlash on the machine, I've tried several different combinations of feeds and speeds, I've tried Carbide and HSS and they all come out with the same finish.
As you've suggested, I'll reduce the number of nodes and see if that helps.

Michael

Yes, I understand - I looked very closely at that area. I see nothing but good smooth vector lines. I don't believe reducing nodes will help, but it is worth a try.

[Pete Cyr]

https://www.foothillsbsa.org/cnc-files-arrow-light