locating section cuts in drawing or on model - how

john_ferguson402

I've been using Pro/E - Creo since 1988 (when it ran on Suns and came on QIC Tapes.  I've agreed to teach a solid modeling course at a local college where OnShape is the application du jour.  I've been coming up to speed and find it truly wonderful and, I think a lot easier to learn than Creo.

There is a small problem with nomenclature, fair enough. Some features are not named what they are in Creo, but for the most part I've figured it out and I like it a whole  lot.

I so far haven't been able to figure out how to do something with OnShape that I do a lot of.

I make R/C planes.  In Creo, I design wings using a swept blend of the airfoil(s) I want.  I then pattern parallel planes transverse to the spar where the ribs will be cut, then make sections on these planes, show the sections in a drawing, export drawing as DXF, make up what will be the CNC input in Autocad, (clean-up, add lightening holes, nesting, etc) then export DXF from autocad to SheetCAM, a 2 1/2D program which makes G-Code from DXF input. Then I cut the ribs on my router.
I realize this sounds complicated, but once I'm in AutoCAD, it goes pretty quickly.

I would like to do the same thing in OnShape, but so far cannot find a way to dimension the planes  of the sections.  If I need 10 ribs on a wing shape like a Spitfire had, I need to control by dimension where each section is cut. I can cut sections in drawing but there seems to be no way to dimension the cut there. Should I be looking at Intersection?

If you know how I could do this, I don't need step by step instruction, just tell me what you call this sort of process.

thanks, John Ferguson

tim_hess427

Hi John - If your end goal is really to get the profiles cut on your router. I think you would be better of doing your cuts in the part studio. Here's what I might try (in the part studio). Onshape's drawing tools are definitely more suited for simple dimensioning/callouts of profiles rather than manipulating geometry. 

1. Model your airfoils as desired.
2. Create as many offset planes as desired at your cut locations. (I think there may be a feature script that can make a pattern of equally spaced planes, but I'm not very familiar with it. Depending on the number of cuts you need to make, setting up the planes manually shouldn't be too much of a problem.)
   
3. Create a sketch on each cut plane, and use the "Intersect" tool to create a profile of the airfoil where it intersects the plane. (You could even do your clean-up work on this sketch be adding lightening holes and other features if you want, then they would update automatically if your airfoil changes.)
4. Then, you can export each sketch as a DXF.  

Hope this helps a bit!

tim_hess427

Hi John - If your end goal is really to get the profiles cut on your router. I think you would be better of doing your cuts in the part studio. Here's what I might try (in the part studio). Onshape's drawing tools are definitely more suited for simple dimensioning/callouts of profiles rather than manipulating geometry. 

1. Model your airfoils as desired.
2. Create as many offset planes as desired at your cut locations. (I think there may be a feature script that can make a pattern of equally spaced planes, but I'm not very familiar with it. Depending on the number of cuts you need to make, setting up the planes manually shouldn't be too much of a problem.)
   
3. Create a sketch on each cut plane, and use the "Intersect" tool to create a profile of the airfoil where it intersects the plane. (You could even do your clean-up work on this sketch be adding lightening holes and other features if you want, then they would update automatically if your airfoil changes.)
4. Then, you can export each sketch as a DXF.  

Hope this helps a bit!

john_ferguson402

I'll try that. sounds good.  One of the great benefits of OnShape is I can work either at  home or the shop. I have a single Creo Subscription which has a work-at-home feature but not for their CAM add on which is what I most frequently need to fuss with.

PeteYodis

@john_ferguson402 For drawings of parts and part studios, you can show/hide sketches from the part studio on those views and then use the sketch to snap all your different drawing cutting lines to.  Sketches from the part studios are fully associative in drawing views, so changes propagate as you would expect.  To show a sketch in a view of a part or part studio, just right click on the view, select "Show/hide sketches..." and pick the appropriate sketch.  

john_ferguson402

it looks like one can generate a sketch by using the intersect function. I think I should be able to figure this out.
thanks
john

romeograham

@john_ferguson402
You may also find some value in the Custom FeatureScripts by @darren_13:
https://cad.onshape.com/documents/4bf18c75321ea2c8c2ea770d/w/978aece63f59e09169309756/e/b319e7a87bba701e3e02a0fa
It generates airfoils, but seems to also do some interesting stuff for creating ribs.

(Haven't used it myself, but there's a fair amount of discussion by folks who do).

Best,
Romeo

john_ferguson402

thanks - looks interesting