Cutting in 3D

[pauln]

Yet Another Program to Review !!

For those interested, there is a new program for either 2D or 3D tool path creation. And by the looks of it and the prices, it might be worth looking into. Plus they have a limited time working demo.

See it at: http://WWW.rams-software.com/

Paul

[ligneous_in@yahoo.co.uk]

Can relief carving on wood be done using Rhino1.1 models and MillWizard. If yes, please let me know details.

[rgengrave@aol.com]

Mark yes you can do this, there are many 3d stl files on the net you can use but I have now seen any I would want to cut.

What you do is open the stl file in Milwizard and setup you bits for cutting, you will need to make setting to get the best results.

If you know how to draw 3d? you will not have any problem designing your own

Ron

[gel3]

How or where do i download the 3d driver to cut a 3d object for shopbot?

[Gerald D]

Presume your are talking about the driver that must be loaded into Vector? The one that is labelled "shobot2d" is the only one - it gives the 3d results.

[nels@tikizone.com]

I Have been trying and trying to get vector and/or the dxf translator to convert some 3d dxf files I have into sbp files, but it just won't cut it (pun intended). The dxf file is to big (i gues) to load completely into vector (it's 2.5mb) so all i get is half a model, or with the dxf converter i just get an error log reading, ok,ok...and a sbp file with just a JZ command. Any Ideas?

[bwclark@centurytel.net]

Joa,

Yes, the ShopBot G-code (I assume you are using
G-code here) does not support arcs in the XZ or
YZ axis. Also, the ShopBot controller does not
support 3D arcs (not many controllers do).

If you are using Bobcad or Vector, you need to
convert these arcs to short line segments. In
Bobcad, you "interpolate" (under the 3D menu)
them. In Vector, you Break-Interpolate (under the
Change menu).

Hope this helps. If not, email me and I will send
you more specific directions for either Bobcad or
Vector. If you are using another CAD package,
some manual reading will be in order.

Good luck,

Bruce Clark
bwclark@centurytel.net (mailto:bwclark@centurytel.net)

[chandler@n-link.com]

Joa,
I think it has something to due with how you are drawing and converting the arcs. I will send you 3 files. One is a 3" radius arc in the XZ plane, one is YZ plane and one is at 45' to the XY axis. They work for me.

[Don Chandler]

Joa,
I made another program tonight like the one I sent you. 3" radius at 45' to x-y plane. I cut a piece of cardboard to this shape and held it up to see if the cutter followed it correctly since it is hard to tell by watching an air cut in this plane. It worked perfectly. One thing I did notice is that the machine will only move as fast as the slowest axis. You need to have the move speed of xy and z set the same or it will move very slowly at the beginning and end of the arc and fast at the bottom of the arc,where not much z movement is needed. Do you have the Acc axis?
If you do, try switching the z and the acc axis. You can do this in the software. this would rule out something wrong with your z axis. I'll think on it some more. Are you able to use the typesetter program? It makes a lot of arcs in this direction.

[jharrison@precast.com]

But why in the heck won't mine even do XZ cuts that *aren't* arcs but just connected lines? It doesn't even write the file correctly, just does 2D only (even when using the 3D function of the DXF converter.) Anybody else having this problem.

I know it will cut 3D because I've done it with other files from other programs so it must be in my converter. Any additional advice?

(oh, I'm using the latest converter plus have tried the old ones and they all seem to react the same way, plus I've viewed my DXF in a couple different CAD programs and the polyline is definitely in the XZ plane and looks just fine.)

Thanks again!

Joa

[dale]

Joa Here's my 2 cents worth
Last summer I tried cutting an arc that also moved in the z axis. I was using a vee bit and wanted the end of each toolpath to come to a point. Mastercam gave me the right toolpath, however, the Shopbot software will not interpolate arcs in z. The G-code converter didn't add a Z value to the CC line but this is moot because the controller will not cut it anyway. Mastercam has an option for converting arcs to line segments. You can set the line length as low as .0001". I used .010"
When the G-code was converted to SB there were a lot of M3 lines to create the arc.
I don't put a lot of faith in DXF these days. I have had to program a lot of parts lately where the customer has sent me a DXF file and I have had to spend a lot of time editing the drawing before I could write the toolpaths.
Someone posted that DXF version 12 works better. This is true. I have had nothing but trouble with V13 or V14.
Like Bruce, I have the capability to program arcs in all 3 axes. If you need help send me your file.
Good luck
Dale
lakemar@accel.net (mailto:lakemar@accel.net)

[gordon@shopbottools.com]

The interpretation of 3D arc entities can be a problem because there are many different ways that they are handled by the various CAD/CAM programs. At this time the ShopBot Workshop software doesn't support direct arc or circle entities outside of the XY plane. To use them the DXF converter we would have to interpolate them in the conversion process.

However, ShopBot is perfectly capable of cutting 3d arcs if they are first interpolated. There are several programs that will interpolate them before saving as a DXF. TurboCAD will interpolate arcs by exploding, but it is hard to control the resolution. Vector will interpolate arcs in any plane to whatever resolution you need. BobCAM doesn't support arcs outside of the XY plane and thus automatically interpolates them. This is why they work for Bruce. MasterCAM, SurfCAM, and various other CAM softwares support arc interpolation and are very good at outputting 3D arcs that will work in ShopBot.

There are several alternatives to using DXF as format for bringing tool paths into ShopBot. There are programs that now output native ShopBot code and don't require conversion. Currently, the programs that do this are Vector, SignLab, and EngraveLab. We hope to have more programs that support our format in the future. Fanuc g-code could be considered the next best alternative. Most CAM softwares support it and can be converted with the g-code converter that is now being packaged with the latest releases of the ShopBot Workshop.

Unfortunately, there aren't any alternatives to using DXF when generating 3D cutting files from CAD. There are inherent limitations to this format and differences in the way it is output, but it is still the most common and universal format available.

As for the DXF files generated in AutoCAD LT: I would be interested in having a sample file that has been a problem so that I can make whatever additions necessary to the DXF converter to handle the problems. To date I haven't had any problems with LT, but I may have not tried the right things either.

[birdsofplay]

I believe that ...
Mostly, it's the CAD program's DXF converter that we have to put up with. Converters are not all the same and it's the interpretation of the DXF spec thats left to the programmers.

Mine wont do arcs in Z either so I use a b-spline line types for those "arcs"/curves.

I found that, in my CAD, there is a WHOLE MESS of settings that greatly affect the DXF convertions.

Also ...
I found the the "number of segments" used to approximate arcs ( in x or y ) was only set to 10.
This lead to noticable "faceting" of larger arcs.
So, I edited that "DXF settings" file to be 100 segments for each arc.
OK, it made the programs a LOT larger but the arcs got a WHOLE LOT smoother now.

Consult "your" CAD FAQs or call em for these kinds of details.

I use MicroStation, but I have to admit that it came cheaply to me because I am a Sys Mgr and I obtained a "home use license". Otherwise I couldnt afford it either.

I will say that I got a chance to try a friends
Quick CAD 200 ( an autocad product ) and it seems to do great as far as 2D goes.
And at sub $100 it looks like a pretty good deal.

[birdsofplay]

Sounds like a CAD problem to me.

Try some simpler lines in the XZ and or YZ

Like ... try placing a single line from 0,0,0 to 6,6,1, or whatever .
and then try converting it.

This problem does sound wierd.

I'd certainly take Bruce up on his offer though.

For fun you can find the DXF specs out there on the net. Or I can send em to ya.
I dont have em at hand just now.

Or go to this site for a host of converters ...
ftp://sunsite.lanet.lv/pub/mirror/x2ftp/msdos/programming/convert/

let us know whatcha find out

[joa]

I draw up an arc in the XZ plane and then convert it (in UX 3D mode) and the SB won't cut it, what's going on? It just plunges to a set depth and then arcs in the XY plane.

Anybody else successfully cut in the XZ or YZ plane??? Tips???

Thanks!

Joa

[joa]

Don, I tried all of yours and tried all kinds of things. They run but only in step-by-step mode (FG) and you try to run them one axis doesn't run which is weird.

I drew up a simple polyline in the XZ plane and saved it DXF and my DXF converter won't touch it. Just recognizes two axis' and won't do the Z axis. Wonder what's going on. It's really bugging me since I need to do a job with XZ moves. Any tips?

Joa

[joa]

I'll send you another file from here at work Bruce since it's made with the same CAD program (AutoCAD LT) and then send you one from home. What's weird is that the file "looks" fine in both ACADLT as well as TurboCAD. Usually if I'm having problems I can do a save-as in TCAD and it will fix them. Something crazy going on though.

I'm not in a hurry but need to learn how to make this bugger work since I have some work coming that requires XZ moves. I'm trying to start simple and get that working first.

Thanks for the help!

Joa

[bruce_clark]

Joa,

Send me your file with your XZ arcs and I will
look into this for you. Also, if you need it
right away, I can just convert it with Bobcad and
the G-code converter (I know that combination
will work for you).

Bruce Clark
bwclark@centurytel.net (mailto:bwclark@centurytel.net)