hey. where did my thread go

[fastimes]

come on mods. now we are deleting threads due to opinions. this is america. freedom of speech. put it back on and lets finish this.

[dertsap]

it ain t america ,
its the world wide web , the information highway

[lakeside]

Originally Posted by fastimes new with sheetcam. seems that when we design a circle or square in bobcad or omax and load them in sheet cam the cutpaths don't seem to have smooth edges all the way around the part and they arent cut smooth. here are a couple of examples. is this a simple setting that we are overlooking. please help before we burn machine to the ground http://i37.photobucket.com/albums/e5...dynacnc009.jpg http://i37.photobucket.com/albums/e5...dynacnc008.jpg

was this the thread that your looking for.If no one answer a thread it kind of like a tree falling in the woods.

[jlenelms]

guess nobody's home

[NC Cams]

I won't play 20 questions although it would be real easy to do so.

The problems you're seeing with the circle cutting are hard to diagnose in your case. Why? You failed to indentify where the problems are with respect to the axis turn around points (CRITICAL to know to address the problem).

You also provided NO machine info relating to the type of machine your trying to cut with (stepper/servo/ballscrew/belt drive/gantry/plasma cutter/flame cutter/???????).

Here's some generic info to an overly generically posed question.

Circles are NOT that easy to cut. Why? Because the machine is simultaneiously change feed rates all the way around the part. If you get into/go thru a speed range that is inducing resonance with a stepper, it will go spazoid - try microstepping.

If you have a lots of backlash (stepper or servo), the thing will tend to cut flats and/or start to chatter at the X and Y direction change points.

Can't tell what's what on your pictured parts. Backlash comp (if you have it) will NOT FIX THIS. Only a systematic removal of backlash will.

The dither at the corners: look into resonance (stepper). You might also want to try running a slower speed to prevent follower error (servo) or step loss/resonance (stepper).

If you have/don't have "look ahead" in your software, the feature may be malfuncioning (have)/intensely needed (don't have).

IF all you posted was the info pasted in by Lakeside, you made it real hard to provide specific solutions, especially with respect to such an obvious lack of hardware information.

Finally, if it is a plasma cutter, two words: RF NOISE.

First 2 words you'd better become familiar with to find a solution: RF SHIELDING.

When it is too hard to mind read or the problem possibilities too voluminous, lots of folks choose NOT to get involved.... This might be why it dropped off the face of the map.

[fastimes]

wow nc cams. that was an interesting read. (if it made since to me). but the thread i am referring to is not the one lakeside posted. the mods and a few others know which one i am talking about. it had to do with some problems and ended up with a few idiots trying to start trouble and get their post count up. to answer some of your questions.
dynacnc plasma machine. servo motors. thc.
don't know anything about backlash. bought table turnkey. would have thought that was set up buy dyna.
don't know if i have look ahead either. explain where to find it on my computer or what program do i need for it. sheetcam, and mach 3 were installed for machine from dyna.
have no clue about rf noise, or sheilding. please enlighten me.
found a company. bought a table. was told you don't have to know much to run one of their tables. so if everything you posted is possible problems, boy did i get suckered. the salesman never mentioned anything about, you need to backlash this, or rf that. i was told, send money, computer and wait until we are real good and ready to send you a table and then call this # everyday for our tech guy to help you rebuild it at your shop and fine tune because when we send it, that means it ran perfect here. to which we have done since we have it. so thanks for your help, but that is not the thread i was talking about. we won't get to see the one i started this thread about ever again because someone got his/her feelings hurt with that being said, now you know alittle more about my machine. please explain in alittle more detail about your post. i am totally ignorant with cnc. but have learned alot just by tooling around with this thing.

[NC Cams]

The problem sections posted are NOT simple to discuss. If you are of the position as you say that "I am totally ignorant with cnc". You need to either:

a. learn what these issues involve and how they can be solved or
b. spend lots of cash with their tech people.

Each of the problem topics I mention has been discussed either in passing or in detail on this and other websites. Systematic working with and solving the root causes thereof will be the only way to eliminate them.

The "magic bullet" fix that you seek simply doesn't exist!!!! This is especially true when it comes to ANY issue involving RF noise and the elimination of problems associated therewith.

The following link should help you in resolving option A above:

CNC Information

specifically post #15

BTW, if you do a search of 'plasma cutters' on this website and read thru the threads, you may find a case where someone had similar problems. Their sollutions might be a good place to start investigating with your system. Plasma cutters can have some real issues with regards to RF noise.

Why? A plasma arc is essentially a huge electical spark albeit much more controlled. What do elecrical sparks to to TV and radio reception? Is it even remotely possible that the static is doing things to your controller?

Either goya and start researching or spend the cash. If you do things one way, you'll be smarter in the long run as you will know more about what makes your machine go and run, but you may not be making parts right away.

Do it the other way, you'll make parts sooner but make your tech support guy wealthy fixing what may have been a piss poorly engineered system in the first place, at your expense no less.

Moreover, by doing it this way, you still won't know didly about your machine and you'll still be "...totally ignorant with cnc"

Your choice.... which will it be???

EDIT

These links will help you a lot too:

http://www.cnczone.com/forums/showth...662#post186662

http://www.thewarfields.com/MTCNCDictionary.htm

END EDIT

[lakeside]

Originally Posted by fastimes come on mods. now we are deleting threads due to opinions. this is america. freedom of speech. put it back on and lets finish this.

Well it looks it NC CAMS found your thread