4-axis cutter with turntable

[bach]

Hello,

We have built a 4-axis (stepping motor driven)Hot wire cutting
machine. We allready have software to convert contours in NC
code and cutting works fine.

Now we are introducing a turntable to cut assymmetric 3D
shapes and ruled surfaces but i'm looking for a way to extract 2D contours from a 3D model drawing file.

By sending a new 2D contour everytime the table turns and performing a new cut. It's my final work in studying industrial engineering. does anybody have a clue?

Thanks

The attached file shows a representation of our machine

[HuFlungDung]

Could you align the part axis with the turntable axis, then create a vertical cutting plane (perpendicular to the wire) to slice the model and then create profile information along the slice? Rotate the part around the part/turntable axis a bit, and the recut, etc. I don't know how you would automate this in software, but that would be the mechanical aspect to it.

BTW, I would call your machine a 2 axis + a third axis if you add the turntable. Master and slave count as 1 axis

[Bloy2004]

Huff..
Hmmm.. Taking bach's word, I believe that machine has independent axes at each end of the wire. This would then be the four axes. Maybe the mechanism for allowing wire to lengthen and keeping the wire taut isn't represented.

[bach]

Yes it is a 4 axis independant controlled machine.
We are still working on the wire length system.

first we used the DCAMCUT software application to cut 4-axis
workpieces, but there seems to be something wrong with the
postprocessing because the NC code for the U-V axis
was wrong. So in the meantime this would be the only solution
to go 3D .

Unless the pro's on this site can help me out.

thanx for the replies allthough.

[HuFlungDung]

Ah, I see about the 4 axis. I was imagining a fixed length wire

Sometimes too many degrees of freedom just creates a clutter of too many ways to do the same thing.

[vacpress]

I have no usefull advice, but i am very curious how you will solve your problem..

Is the software your using custom? Control Sw?


Thanks...

[Max]

Wow, I'm building one almost exactly like that ...
The frame and controller are done, now working on the motor - belt drives
I've been modeling mine after this unit
http://www.croma-foamcutter.com/uk/F...tGDprocess.htm
The link will give you an animated process of the machine cutting.

I'd be interested in what software you find
The closest I've come to is Indexer lpt as a possibilty, but until I get the machine running I won't be able to try out the software demos

I'll try by this weekend to post some pics of what I've built.
The two X axis (left to right) are independent and so are the two Y axis (up and down)
I also have the turntable and a lathe table ready to be mounted ... first I need to get the basic machine moving.
I think I've solved the hot wire tension problem by using a constant tension spring assembly pulling 6 lbs.

Machine dimensions: X axis (left to right) 5' .. Y axis (up and down) 4' .. distance (between the two Y axis - cutting width) 2'

[vacpress]

MAX! Where are those pics?

Curious to see what you do.


What are you going to use it for? I want one, cuz i like the idea of making something a little less heavyduty than my planned router. it can be much cheaper and use the stuff I allready have now, like 1" aluminum square tube, and lots of NEMA23 100oz/in Steppers I jsut keep looking at an not using for anything... I wish i knew a convenient way to get some nitinol here in chicago... hate ordering stuff that costs the same as the shipping charge...

[Chagrin]

"nitinol" is "muscle wire" I believe - you're looking for "nichrome" wire which is frequently sold as picture-hanging wire. Any department store will sell this, although as it's braided it might not work as well as single-stranded stuff.

...it does work well for pyrotechnic igniters though

[vacpress]

oh yes - good point - typo. braided nicrhome? whats it for? i need 1 thicker guage strand. I would ideally get a few guages to see what the different properties are. heres an image of my prelim design. it uses aluminum window C channel for the ways.