Learning some kinematic math....

[Watcher]

Hi folks!

 

Lately my interest in kinematic math grew up considerably. 5 axis calculations are amazing to me.

 

So, hopeless to get something about what I´ll ask for, I´ll try, though:

 

Does anyone here knows or reccomends a book or some reading/exercises about kinematic math for 5 axis machines, vector math and so on? (Dave Thomson/Paul Decelles are such books, but surely they are not available ones.... :-)

 

Thank you in advance,

[crazy^millman]

Look for some Calculus books and look in to Vector Equations here are some links:

 

Link 1

Link 2

Link 3

Exmaples and Excerises

I like this one with a PDF

This one has some good exmaples of Math.

 

It has been about 17 years since I took the subject but still have my books and the biggest thing is understanding the equations and then figuring out how to apply them to the MP language or any computer language that the computer or program cn make sense out off.

 

The thing I think most people forget about with post processors is that they are a translation utility. They are given the Vectors and the related coordinates from the NCI language and that is done within the MP.dll and the post is taking that information and putting it in a format and language that the machine tool can understand and use for making the part. If you have ever seen APT source code you would think it is NCI different but still similar enough to make heads or tails of it. APT source is easier to me because you have the commands that go with each line to get an idea of what it is doing. Where as with NCI you have numerical commands that are telling it what to do about the same thing just different ways of doing it is all.

 

Vectors are really not that hard just think of the idea of the planes and lines being the driving force behind these equations and being able to think in 3d space is easy once you understand the concept of the equations and how they relate to the overall function of the place in space they are defining in this case happends to be a machine tool in which we are defining and using the equations inside of in which to accomplish the task at hand for the application we have so desired to make it work for us.

 

HTH

[crazy^millman]

If you want some heavy reading this one I really like: ASYMPTOTIC APPROXIMATION OF EIGENVALUES OF VECTOR

EQUATIONS

 

Hope you enjoy

[John Summers]

MP, the postprocessor language, can output -.NC files, or pure ASCII files (just numbers). You can also create a dummy -.NCI file, and and do all computations within MP, or input a string of points or other kinds of data thru the buffer files (-.TX1 thru -.TX0, 10 possible files, either input or output). There are also 3 other possible outputs besides the -.NC file: -.SUB, -.AUX, and -.EXT. These 4 files can contain blank lines, the buffer files cannot. Blank lines are useful when you want a string of lines:

X Y Z (EOF)

X Y Z (EOF)

blank (space, EOF)

etc.

I have some examples of pure computation, if you want some.

[crazy^millman]

John if you do not mind I would like a look at that.

[Greg Williams]

John,

 

I am interested too if possible?

[Zero]

me three

[Kyle Waters]

John,

 

I also would like to add my request

[Guest]

i am interested too, please.

[John Summers]

I'll get some files into the FTP site next week. If anyone has a specific math problem, I'll look at that, if it's not too difficult. Here's one typical problem: files like the ones that Ron Teh Crazy put up are good examples. They are also terrible, in that they are in a rather difficult mathematical notation. I'll convert some of these to the MP language. In general, it's a piece of work to convert some math that's in a book to a program in MP (or C, for that matter). Also, a lot of 'book' problems are without a diagram, with labeled vectors, and angles. Even some labeled ones use inscrutable greek symbols, which need conversion to labels which have more than one character (v2x, etc.)

[Colin Gilchrist]

Yes please. It is so cool to have the guy who wrote the MP language helping us out. Thanks John.

[crazy^millman]

Sorry John those were just some one I found off the top of my head. If you got better ones I am all ears because I respect what you say and can show.

[Watcher]

Hi folks!

 

Thanks a million for the quick feedback, specially you Ron. In fact, I was not expecting so many entries for this topic....

Thank you all, and Ron, muito obrigado!

[John Summers]

Ron, I was not criticizing your examples -- they were good. The problem is that math books are written in a different language than the programs that solve math problems. My old Analytic Geometry books look a lot different than the code I use to solve the same problems, yet fundamentally the math is the same. I marvel at the renaissance astronomers that worked out planetary motions with logarithm tables. What they wouldn't have given for a $10

calculator.

[crazy^millman]

Yeah well I am that guy that sat down and did the pages and pages of calculations when back in school. We were not allowed to use calculators and had to show all of our work and could not leave anything out. I had one problem I think was about 15 pages and I think it took me like 3 hours to do so I can kind of relate to what they went through I think they use to spend month if not years doing problems.

 

John just took at from wish I had the ones you needed and not from the point of bad ones just the only ones I could find in short notice.

[TonyNanni@BNB]

We have an optimization software package for our 5 axis programs called "CAMPLETE". This is a great asset and works well with MC, it reads NCI files directly. It has feed rate leveling based on the machine kinematics, it also linearizes a tool path and add intermediate points on large 5 axis motions, MC works on surface errors but doesn't detect errors based on machine and fixture kinematics. That is a lot of math to learn and it is great for us dummies to have a software program to rely on.

[Guest]

hi john...

you said last week that "I'll get some files into the FTP site next week".i am looking forward to that.Can you mention in what folder they will be uploaded?

thanks in advance

[Bob Hedrick]

Here's some other 'light reading' on the subject. Most of it is with regard to robotics, but a CNC machine is just a specialized robot.

http://www.engr.mun.ca/~gmann/engr_7944.htm

http://www.techsystemsembedded.com/Robotics.html

http://users.rsise.anu.edu.au/~chen/teachi...5/lectureNotes/

 

There is a lot more information than you need in these links. Stick to the 'position', 'kinematics' and 'inverse kinematics' sections, unless you're really into the math.

[crazy^millman]

Well I like it all so I will be reading all of the sections thanks for the links.

[John Summers]

I think there is a file VLIB.MPK or VLIB.ZIP in the Misc. section on the FTP. I can't seem to get on the FTP from home. I'm preparing another document, which I'll send soon.

[crazy^millman]

It is VLIP.MPK for the file on the FTP.

[Watcher]

Priceless topic, isn't?

[Takashi Sato from Ai Solutions.]

Hi guys,

I found VLIB.MPK on ftp.

 

but what is .mpk extension?

Is it a mastercam packed file?

[John Summers]

Yes, it is Mastercam's packed file. Unpack with MUNPACK.

[Takashi Sato from Ai Solutions.]

Wow, Thanks

I didn't have any idea of .mpk files until today.