Challenges exporting DXF from Rhino into FlowPath

Rhino Rhino for Windows
1

I have a brand new Flow waterjet and I’m using Rhino for my design work. Flow has FlowPath, which opens DXF and can then turn the DXF into a cam file that is opened in FlowCut which is the SW that actually runs the waterjet.

I have yet to find a way to reliably import a DXF from Rhino into FlowPath. The issues vary - sometimes I am able to get something into the app but it’s littered with errors (eg gaps in lines). Yesterday I took a bunch of files I created to run a laser cutter (after much trial and error) and when I opened those in Flow I either couldn’t see anything at all (in the case of the smaller files) or FlowPath crashed (in the case of a big, complex file). In the flow training class I took we had to resort to re-drawing the imported rhino file in flowpath rather than fixing all the errors. In this class the instructor did mention that “flow doesn’t like splines” when we were doing the work.

I know that file transfers are funky and that its easy to point the blame at either package. I just want stuff to work. As an experiment we took one of the DXF files that worked in the laser cutter but that doesn’t work when directly transferred from Rhino to FlowPath directly (it came up blank in Flow). We then opened the rhino-created file in cambam, where it looked fine. We then did a file.save in cambam (modifying nothing) as a DXF and imported that resulting file into Flow and it seems to work just fine.

So what I’m looking for is help in how I can create in Rhino and cut in Flow without requiring 3rd party intermediaries.

I’m going to ping Flow customer support as well (they don’t seem to have a forum!). Will post what I hear back.

2

Hi Peter - can you post an example 3dm files with a few of the curves that do not work well along with’-

  • the dxf file you get
  • the exact settings for the dxf export.

thanks,

-Pascal

3

I will get you the exact files Tuesday when I’m back in the shop.

4

Does Flowpath open IGES files? I would try IGES file format if you can.
Rhino’s IGES export is rock solid. Rhino’s DXF export is not.

5

FWIW also see this issue with the DXF/DWG exporter, where it can be that aRhino does not export all objects:

-Willem

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I don’t know if Flowpath opens IGES - I’ll check and try it if it does. Thanks!

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Also, along with what Pascal asked for, if you have a dxf file that you have opened and re-saved in Cambam that works when the first dxf file from Rhino doesn’t work - I think that’s what you described above, right? - maybe we can see what the difference between them is.

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I’m having similar problems with Rhino5, both Windows and OSX versions.

I’m using a FlowPath package at TechShop PGH and it only supports older versions of DXF. The TechShop suggestion is to take the exported DXF, run it through VCarve to fix open/duplicate curves, then use that DXF file with Flow. Flow software doesn’t handle duplicate lines/curves very well and sometimes turns a long curve into a bunch of short curves, each with its own pierce action.

The files converted by VForce mostly works except my metric Rhino files come up slightly smaller than designed. A hole for a 3mm, 4mm, or 5mm bolt will be just small enough that I have to drill out the hole to get a bolt to fit. On larger cuts (600mm x 600mm) I often get a piece that’s, say, 597mm x 597mm.

As soon as I can, I’ll go in and cut some SAE and Metric test files without the VCarve filter and see if the dimensions are correct.

I tried IGES export yesterday, directly loading the file in to Flow. The resulting file was unusable – for one file, all of the straight lines were missing but all of the curves were present.

Right now I’m trying to finish up a client project but I’m keeping all my .dxf files. If there’s a good test case I can prepare, I’m happy to my own hours into it. Techshop is 10 minutes from my studio and I’d much rather cut gears and complicated panels on the waterjet than a ShopBot or CNC rig.

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Hi,
Sorry for my bad English language.

I’m having similar problems with Rhino5, both Windows and OSX versions.

If you have problems, best solution, please attach one of this problem file (or part) here.

The TechShop suggestion is to take the exported DXF, run it through
VCarve to fix open/duplicate curves, then use that DXF file with Flow.
Flow software doesn’t handle duplicate lines/curves very well and
sometimes turns a long curve into a bunch of short curves, each with its
own pierce action.

Big advantage in Rhino is function “_convert” with parameter “output as arc” and save as DXF (I use R12) with activated “Top View”, that’s what many g-code programs like.
Why? Programs with standard G-code produces for output same geometry, so lines and arcs. (Example G02)

So if you convert this geometry directly in Rhino, you will see the deviation already in Rhino.

Duplicates can be detected via “_SelDup” command.

For more control, look into RhinoScript, You can identify self-intersection, duplicates and other.
Again here is Rhino also very flexible.
(Currently i just write for myself a script for these operations, 90% complete and it rocks)

And most problem are make different tolerance.
So it’s bad idea to work in Rhino with tolerance 0.005 and in other programm with tolerance 0,02, which after import often leads to open contours. (Produced by different rounding factors)

In summary, i can say DXF-Export from Rhino to CNC is very good for me, so the best.

-Best regards

10

Hi, so I made some progress.

One problem I’m having is this:

The Flow software wants an older version, R9 if I remember correctly.

I switched to DWG and a format from 2004 or so and things got a bit better.

11

You’re kidding… R9 is from, like, 1987…

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I just leave this here:

-Willem

4 Likes
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I need to stop in at TechShop on my way home, while I’m there I’ll doublecheck the documents from my waterjet class.

14

R9 ? => I do not believe that !
What settings do you have for export (DXF export scheme) ?
What tolerance is used ?
What a drawing element make problems (Polylines, Spline or what) ?
Avoid NURBS/Spline curves, use command “Convert” output => Arcs this produces polycurve with Arcs and lines and this elements are 99% readable.
If not described, try different DXF versions.

For milling we use program from 1999, => exported from Rhino everything comes without problems layers, colors and…and that is great !!!

Best regards

15

My notes from the class say “R10”, so not as bad as R9, I guess.

I’m cutting gears and panels originally laid out in 3D using curves, objects, or whatever makes a good object. I do a “Make 2D Drawing” of the object, clean up the unwanted lines, then export that as DXF.

Switching to DWG cleaned things up but I’m still running in to problems where a metric cut is a bit too small. Today I had some 11mm dia holes show up as 10.9 something holes, I had to cut them out with a drill before I could fit 11mm bushings.