Hi All

UPDATE - plugin available in this post 2010-12-22 ...

I've been working on another plugin - as the name says - sketchup to *.dat, where the dat file is a file for a hotwire cnc foamcutter (typically GMFC, but other cutters use the same file types).
The plugin works both ways - it can both read and write *.dat foamcutter files.

It'll no doubt be of use to someone
This means that we can now export surfaces directly from sketchup (or read and produce sketchup surfaces from the data) and cut them on the hotwire cnc foamcutter.

If someone can check these on a PC and perhaps any data created on their foamcutting software, I'd be obliged !

Cheers

Neil Attached files PhlatDAT.zip (153.4 KB)Â

 

This plugin looks very nice. I've been going through the examples, but unfortunately the DAT format doesn't seem to be compatible with my cutting software. The DAT format needs to have XY coordinates starting at TE and continue over the top side to the LE and around back the bottom side to the TE. The Phlat example has it's first point starting at the spar channel in the mid of the wing. Does anyone know how to use the Phlat plugin to define the DAT starting at the TE? Thanks.

Scott

 

Hi Scott

Sadly, there are many 'dat' file formats - as I found to my annoyance while writing the script. The 'dat' file format doesn't necessarily have to start at the TE - the data just requires to be contiguous.
Your foamcutting software should allow you to select a starting node from the data and a cutting direction.

It's been a while since I wrote the plugin and age does nothing for the memory

As I recollect, the *.dat file nodes are written in the order they are created from the object surface (ditto in reverse). To organise a different surface starting point would require a change to the plugin to allow an edit start point and direction.

However, something that you may wish to consider is the issue with creating [say] a tip and a root rib with spar cutouts. Without spar/LE cutouts, your cutting software will have no issues as the shapes are a scaled version of each other - adding spar cutouts (of the same dimension on each 'template') removes that proportionality - unless the foamcutting software has a 'waypoints' option (ability to define points at which both ends of the hotwire should reach at the same time) then you will end up with a paint stirrer/children's cricket bat/propeller

If the tip and root 'ribs' with spar cutouts are the same (parallel chord) then there will be no problem. As soon as either of the ends are not a scaled version of the other, then you will have issues without a 'waypoint' function.

As an aside, I wrote foamcutting software for the Mac many years ago that only worked on the waypoints principle - that way, you could create your 'templates' on any graphics system and guarantee that both ends and the section in between would be correct. One of the advantages is that you could have an elephant at the root and a camel at the tip - as long as the feet nose and tails and humps were set as waypoints, then it would be fine (the section in the middle would be a camephant or an elephamel )

Apologies for the wordy discussion.

Cheers

Neil

 

Neil. Thanks for the reply.

Now that you mention it, I see the issue with spar channels. I'm not too concerned about this as Anker's Foamcutter software has built in channel creation.

There seems to be a lot of frustration in finding good DAT files as there seems to be no standard. What I have noticed is that some people have suggested to follow Martin Hepperle's format.
http://www.rcgroups.com/forums/showthread.php?t=1472481
http://www.rcgroups.com/forums/showthre ... 16&page=56
http://www.mh-aerotools.de/airfoils/index.htm

Unfortunately my foamcutter software needs to see the points starting at the trailing edge. So I'm in need of finding a conversion utility to reorder the Phlat2DAT points to comply with Martin's DAT format.

Since there is no way to define the DAT output from the script, is there any way to tell Sketchup what point #1 is? I noticed using Profscan the point order changes if the faces are reversed (right clicking on a selected face), but still no luck.

 

I don't think I'd even remotely like to enter that argument

Take a look at the PhlatFoil Tool - there is a wee included tool called 'PhoilPal' - it converts (or attempts to ) various aerofoil data formats into one 'standard' format that will suit the Phlatfoil tool - kind of what the 'standards' argument is all about.
As it happens, you can create a surface, use Phlat2Dat to create the *.dat file from that surface then use PhoilPal to convert it to a *.foil file. The *.foil file data is sorted to start at the right and work clockwise and is in '.dat' format using TABs instead of spaces.
This may help you along.

Let me know how it goes, I may get some time in the winter to get some more coding done (if I can get time to finish my laser cutter that is :roll:

You could always sort the data using either Numbers on the Mac or Excel on both platforms.

Cheers

Neil