Jerky motion on curves

[brian]

My bot has just developed a jerking motion when doing curves.It also does small radius curves at a snails pace then speeds up on the straights.The last thing I did on the bot had some serious chatter marks on it.I know you can change the setting but I haven't.We often have brown outs and blackouts here in the winter, could this effect the default setting.

Brian

[erniek]

I had that problem with the small radius curves being cut at a snails pace. I found that the ramping settings somehow got set really slow. I set the ramping settings to default and it was fine again.

[myxpykalix]

You may want to take a real closeup look at your files because some curves are made up of a series of straight lines as opposed to curves. Depending on the program used to create the file you need to make sure its made with bezier curves and when you pick the post processor for cutting make sure you pick the "arcs_inch" pp (assuming you are using inches not mm.)

[brian]

Thanks Jack
I took a look at my files and Noticed the small straight lines in the curves.I don't know why it changed.I have used this same program for a while (Artcam)and had no issues.Thanks again

Brian

[ron_moorehead]

Did you import the file from AutoCad? I have noticed that some times but not all the time I will import a file from AutoCad and all the lines in a curve will turn in to straight line, I just click on the node to smooth it out. So I always check my curves after importing a cad file now.

[brian]

These files are being done in artcam pro.I still can't figure out how to change the vectors so they are smooth curves.I've always used the arc_inch post processor for toolpath creation.
Any Ideas?
Brian

[garyb]

You can use the spline vector tool or enter node mode and select the nodes you wish to change and press "S" for smooth node

[brian]

Is there not a way to have it produce smooth curves without having to change it.I looked to see if there where any setting to change but had no luck.I'll admit to being a bit of a Luddite when it comes to computers,so I,ll use Gary's suggestion.

Thanks again Brian

[navigator7]

Luddite
noun
a member of any of the bands of English workers who destroyed machinery, esp. in cotton and woolen mills, that they believed was threatening their jobs (1811–16).
• a person opposed to increased industrialization or new technology : a small-minded Luddite resisting progress.

Sorry, Brian...I had to look that one up! Always eager to improve my communication skills.

Would you like to sell your machine before you destroy it? ;-)

~~~~~~~~~~~~~~~

I believe your machine is cutting those short jerky movements because it is doing precisely what the file is telling it to do.

I did 3D printing. People would send me files (from many different programs) that were saved in the "course" mode.

Designers do this to speed up the computer .
As I had the stl file, there was little I could edit the file.
If I printed the stl, saved in course mode, the finished product came out ....well ... like a bunch of teeny triangles.

I believe all curves we see on our puters are really straight lines. I don't think any puter program draws a true curve....just many little lines.

What Gary says above says it all. I'm thinking "select all" and chose 'S'.

Then.... save-as something else!

[brian]

Thanks Chuck
Always good to see someone thats honing there skills.
It seems with every knew project there is something to learn

Brian

[garyb]

"Is there not a way to have it produce smooth curves without having to change it"

Yes there is, what are you trying to draw?
if you want to send me your .art file I will have a look and advise
Gary

[brian]

Gary
It's not any single project that I'm having problems with.I just noticed recently that the curves in artcam had much more noticeable segmented lines.I didn't think much of it at the time but when I ran the last two files I really noticed the machine jerking on curves.I've now increased the screen resolution and changed the VR back to default(still wondering how it got changed).I'm hoping this will smooth out the
bot movement.
Although if you have any suggestions I'd love to hear them.

Thanks Brian

[magic]

If this is on the machine end as opposed to the resolution - Is this what the Gecko drivers are suppose to do? I don;t know

[garyb]

Brian are you actually creating the vectors in AC or are you importing them? What version and build are you using?
A small sample file would help

[brian]

Gary I'm building them in artcam 9.1.I remembered after I responded this morning that The one file I ran and had the most problem with was an existing file from artcam.Upon revisiting this file I found the vectors to have no biezer curves at all.I was able to smooth the curves out considerable by splining them.
Unfortunately I can,t transfer any files to this computer at this time as I'm using my flash drive to run a file at the moment.I keep my internet and working computer separate.

Brian

[eaglesplsh]

There is a setting within SB3 that tells the control software how "smooth" to cut arc commands. Basically the control software uses this setting to break the arcs into vector segments that are the specified length (or within a certain tolerance to the true arc - I forget which.) When I was first going through the settings on my machine I remember thinking that the default value was too loose.

I'm pretty sure that ArtCam has a similar setting. It's just breaking up the arcs/creating the vector segments ahead of time, for machines/control software that can't do the leg work.

If your drawing is actually made up of line segments instead of arcs, PartWorks has an automated tool "Fit Curves to Selected Vectors" - ArtCam may have something similar.