Need some CAD help

[Harblar]

Hey all!

This isn't a printer specific problem, but more of general CAD issue I'm trying to find a solution to. This might not be the right section for this, but I didn't see any general CAD boards.

I'm currently using PTC Creo Direct Elements (free and pretty good from a part design standpoint). My current project is building myself a high quality lightsaber. I'm making it out of copper pipe and fittings, a sink tube (for the shroud), numerous electronic bits, and of course a number of 3d printed parts (been coming out great, thanks to my Rostock Max V2!!). I've been modeling everything in Creo (in order to learn the program better and make sure everything's going to fit nice and tight before printing and assembly. )

The issue I need help with is actually related to the metalwork of the project. One of the parts is the chrome 1.5" sink tube, which will need to have numerous openings dremeled/cut out of it in order to blend into the 3d printed parts. I've easily modeled the tube and made all the necessary cuts in Creo. My trouble lies in translating these to the actual tube in order to make the cuts. What I would like to do is select all the cut edges and "unwrap" them to a flat 2d plane (maintaining the same edge lengths for each segment) and then print it out at 1:1 scale so I can wrap the paper around the actual tube and be assured an accurate cut that will match up with my 3d printed parts.

I hope that's clear. It's kind of hard to describe. Anyway... I've yet to find a way to do this in Creo, but I know other cad applications are capable of it. (I know blender can do this, but it treats it more as a texture mapping feature so getting a properly scaled and dimensioned image to print might be hard)

So, does anybody have any solutions I might be able to try? (Based on available/free software) I could also provide an STL of the part in question if someone would be willing to help me out directly.

If I could just get this one issue solved, I'd have the whole thing together and working by the weekend. I've been working on it for a month and a half now and I'm getting eager to get it done!

Thanks!

[travelphotog]

Maybe do an STL of the tube and print it out, then use the holes in it as a guide to cut holes in the tube as sort of a template. I would guess you wold have to scale it a bit to fit over the tube, but the holes should scale the same and can then be used a guild for the dremel? Just the first thought that pops in my head.

[Jimustanguitar]

That was kind of my thought as well... Scale up the part so that the actual tube fits inside of it, and just use the printed part as your cutting guide.

[Captain Starfish]

Nice thinking, guys.

We have a PTC guru at work, I'll ask him. I suspect, though, that the sheetmetal unwrap is a one-click function in full blown Creo but you're out of luck in Elements.

[JFettig]

Its actually a surprisingly difficult thing to do - Solidworks 2015 is supposed to have a feature but 2014 and earlier doesn't. There are some very expensive software add-ons that do this and a customer of mine uses it for laser cutting tubes.

Anyway - a proper workaround inside solidworks is to use sheet metal - do 1/2 of the part at a time and put them together, then you can create a flat pattern and print it out.

[Captain Starfish]

Okay, from the PTC guru:

Two options.

1. Copy & convert the cylinder to a sheetmetal part, define a rip line and unbend it. Done.
2. Make a surface copy of the cylinder outside, slice or split it into two halves, and use the flatten quilt operation on those surfaces.

He doesn't know if these features are available on Creo DE.

[Harblar]

Maybe do an STL of the tube and print it out, then use the holes in it as a guide to cut holes in the tube as sort of a template. I would guess you wold have to scale it a bit to fit over the tube, but the holes should scale the same and can then be used a guild for the dremel? Just the first thought that pops in my head.

I'd thought about making and printing a stencil, but was saving that as a last resort since it seemed slightly more complicated/time consuming than if I could just hit a couple of buttons and 30 secs later have a piece of paper i could glue straight to the tube and hit with the dremel. Alas... things that you would think would be simple rarely are.

The issue wasn't so much scaling the model up as it was breaking it up into sections that could be easily printed with minimal/no supports and not warp or bounce while printing. I've been thinking on this this afternoon and I now have a couple ideas on how to do this and get a fairly good result. I'll throw up some prints tomorrow or Thursday and show how they worked.

Okay, from the PTC guru:

Two options.

1. Copy & convert the cylinder to a sheetmetal part, define a rip line and unbend it. Done.
2. Make a surface copy of the cylinder outside, slice or split it into two halves, and use the flatten quilt operation on those surfaces.

He doesn't know if these features are available on Creo DE.

I knew a sheet metal unfold option would probably work, but that is a full version feature. The second method you posted sounded promising, but I've been unable to find anything (help doc, tool tips, or otherwise) related to quilting or even mention of the word flatten, so I'm guessing that means it's part of the full version as well. Oh well... Thanks for asking! At least now I know.

Again, thanks a ton for the quick replies with suggestions and help! Trying to find the answers for CAD related issues on google can be a real bear sometimes and I was really striking out on this topic. Once I get everything polished up and working I'll throw up a build thread with some pics/vids of the final saber and highlight all the cool little bits I was able to print for it and how they turned out. Working with a stock hotend/nozzle and layer height at .1mm and minimal sanding at 80 grain followed by steel wool is giving a nice smooth surface. After a bit of touch up paint/clear coating, it's going to look Nice!