Ski Builders Forum

Anyone have any issues making the transfer over from snowcad to solidworks, etc?

We are trying to take some older dxf files from snowcad and make some adjustments in solidworks and are finding that...
1) The arc of the curve is not actually a smooth arc, rather a bunch of small connected lines.
2) We are having a hard time replicating the outputs from snowcad. Basically....not sure if the turn radius outputs are actually correct. We aren't even sure if the sidecut is actually a real curve. One of my friends seems to think it is based upon the quadratic equation of something.

We are having a hell of a time trying to get this work done. I think my friend emailed Dan to see if he could shed some light on this, but has anyone else found they have issues manipulating work done in snocad is a different CAD program, and that the outputs of snocad aren't exactly accurate?

Maybe we are just crazy, but any help would be appreciated.

I had issues taking the files to a printer to get a continuous printout - it did just what you describe.

Never figured it out - I just printed it on my HP 4000 and cut and taped the profile together

at least the prints all have centering marks so alignment was easy

I've done the same but only an import to autocad, and what it looks like is that in snocad the curves created are actually small chords. They are also all one entity in the form of a polyline.

I have been using snocad for the rough shape, importing the shape in autocad and reworking the segments into one curve.

I have noticed that the points of curvature are not correct (the sidecut curves are not exactly tangent to the tip and tail curves.)

The poly-line curve issue is a result of DXF. That's just the way it does it. You're better off starting over from scratch using Solidworks. Then arcs will be arcs and tangent curves will be truly tangent.

Cheers,

-S

Yeah I just started from scratch - It's pretty easy, just doesn't provide the instant satisfaction as designing a ski with snocad.

And yes, DXF's are always butchered.

In CATIA, you can connect all the dots together (it's the "Fix" constraint), so atleast everything moves together, but it's definately a band aid solution.

I have imported into SWX. I used the DXF editor. You are right in that they import as a series of points not lines.

I have found that it is easier to start from scratch with a base sketch and then export as a full size pdf. Once I have all of the relations defined in SWX, it is easy to change dimensions and have your sketch update automatically or use configurations to make multiple sizes. From there, you can also export as a DXF and go straight into a CAM package.

As others have said, when I did import from snocad, I noticed some oddities such as the transition from edge to nose/tip is not continuous. I imagine that most of these get hidden when you start using "coarse" tools like routers etc. In SWX, you can define these curves as tangent so you know they are right.

I use this software for a living so if you have any specific questions, shoot me a PM and I will try to help.

What I did was bring the DXF into a sketch in solidworks. Then I made another sketch, and used the spline tool to basically match the DXF sketch.

So instead of say 100 points (or more) for the sidecut of the ski... I had 3 points, and just adjusted the arrow bits to get the curves to match perfectly.

I now use that file for my template for skis, so I can just enter in the dimensions I want (length of ski, waist, tip, and tail widths) and then manually adjust the spline curvatures until it looks nice.

SHIF wrote:The poly-line curve issue is a result of DXF. That's just the way it does it. You're better off starting over from scratch using Solidworks. Then arcs will be arcs and tangent curves will be truly tangent.

yes, but you can use your DXF as a guide to "trace" over with splines, etc (as I posted just above)

Can someone recommend a good simple freeware CAD program? All I need is a program that will draw geometric shapes (circles, rectangles and squares are all I need) to scale to dimensions I select. I need to be able to tell it to draw a square 19 inches on a side, for example, then a circle 5 inches in diameter, etc, and to be able to move them around on top of one another. All I can find are very complex CAD programs that are easily a hundred times as complex as I need.
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affiliateelite ~ adgooroo

Try Open Office from Sun . It comes with a Draw/Drawing part.

yeah, SnoCad is based on vertices. If you go to tools, you can actually choose your vertex density. My laser cutting guys cannot use direct DXF exports, their machine stops every millisecond and shakes and rattles the workpiece.

I tried converting the polylines to curves in CorelDraw, and it does a pretty good job. Vertex count goes down by 1/3. Then you can actually eliminate some of those too manually.