Scanning a partial section of a larger object

[exalted512]

I'm looking at purchasing a 3D printer from some upcoming projects, but one of the most necessary one's is also a bit of an oddball. I have a gas tank that needs to have protective plastic shields on the sides. The gas tank itself is roughly 18" long, 7" tall, and 16" wide, but I only need to scan a portion of that to accomplish what I need to accomplish. I have previously made these out of fiberglass and here's some pictures of what I'm talking about.



Since this is a major reason for the purchase, I would like to know if this is possible and what scanner and software I would need to scan the tank and then 'build' this piece that attaches to the bike with double stick tape before I spend the money on the printer since this would essentially be a deal breaker if I can't do this.

The printer I'm looking to purchase is the MakerGear M2.

Thanks in advance!

[DarkAlchemist]

Are you sure the M2 has enough room on the build plate? Those are dimensions approaching the need of a GMAX 1.5XT/XT+ as you really need a larger bed than the object you plan to print.

[exalted512]

I apologize, I meant to put the dimensions of the actual piece too. The actual piece I wish to create (the black piece in the picture) is only 7.5" in length and 3-4" tall. It covers the bulge in the tank so the depth is about 1.5" deep, but the actual thickness will be just about 1/4" thick. The dimensions I gave were for the entire tank.

That was one of my main questions. The tank itself is rather large, but I only need to scan enough to make the piece itself.

[CarterTG]

The most impressive high-resolution 3D scans I've seen so far are those that use photogrammetry. The rules to achieving decent results isn't rocket science:

A digital SLR would be preferable since it permits some of the crucial focal length and aperture adjustments. Aperture should be set to minimize depth of field (no bokeh). Use or rent a quality lens that won't introduce chromatic aberration at the edges.

Shiny and transparent surfaces ruin the process. Make the region matte by dusting it with baby powder or spray with a washable paint. Shoot either in a light tent condition or outdoors in a total overcast (sunless) sky. Photogrammetry will be helped by picking up the focused, unevenly dusted texture on the surface.

Double-stick a coin or other reference object in an unimportant adjacent area. This can be used in the resulting mesh to ensure things are scaled accurately.

Agisoft Photoscan would be my first pick since it doesn't rely on a cloud subscription model. It's been around long enough to generate a bunch of YouTube and community support.



By comparison, I've tested 123D Catch years ago only to find the resulting low-res mesh to be garbage for reverse engineering. Noobs initially gush over the results, but once you strip away the color/texture/UV data, the underlying mesh is generally unuseable. A quick look through the 123D Catch gallery illustrates the lack of high-res scanning being achieved.

[trieutulong123]

I would like to know if this is possible and what scanner and software

[awerby]

The Capture scanner could do this. It would work better if you coat the section to be scanned with some flat white paint, since most optical scanners have trouble with shiny surfaces. Of course, scanning the part is just the first step, but most modeling software would be able to create an offset surface from your scan that would join it to become a printable part.

Andrew Werby
www.computersculpture.com

[curious aardvark]

to be honest, like most things it's usually far far easier to design the part from scratch in a cad program than to try and get a useable scan from anything but an expensive scanner.

Looking at the piece, I don't see any problems replicating it.

Give me a part, digital calipers and an hour or so and I could easily produce a printable replica in openscad.

Basically it's 3 reshaped spheres and a couple of rectangles hulled and cut in half.

Given that it looks like it hets some wear, I'd make it from polyflex (tough and flexible), sand it smooth and paint it.

Doddle :-) (that's english for: dead easy)

[exalted512]

The Capture scanner could do this. It would work better if you coat the section to be scanned with some flat white paint, since most optical scanners have trouble with shiny surfaces. Of course, scanning the part is just the first step, but most modeling software would be able to create an offset surface from your scan that would join it to become a printable part.

Andrew Werby
www.computersculpture.com

This one? http://www.bestbuy.com/site/hp-3d-ca...&ref=212&loc=1

It allows for partial scans of a larger object?

[exalted512]

to be honest, like most things it's usually far far easier to design the part from scratch in a cad program than to try and get a useable scan from anything but an expensive scanner.

Looking at the piece, I don't see any problems replicating it.

Give me a part, digital calipers and an hour or so and I could easily produce a printable replica in openscad.

Basically it's 3 reshaped spheres and a couple of rectangles hulled and cut in half.

Given that it looks like it hets some wear, I'd make it from polyflex (tough and flexible), sand it smooth and paint it.

Doddle :-) (that's english for: dead easy)

I don't think I'm talented enough (or really at all) with building these items from scratch, unfortunately.

[awerby]

This one? http://www.bestbuy.com/site/hp-3d-ca...&ref=212&loc=1

It allows for partial scans of a larger object?

No, not that one. I've never tried one of those, and haven't heard much that's favorable from those who have. I'm referring to the Capture scanner from 3D Systems: http://computersculpture.com/scanning#capture3DScanner

It can capture detail that's quite fine, and comes with the software you need to integrate and repair your scan data.