Can a flatbed scanner help me CAD parts or is there a better way?

[Anonymous]

I have some appliances parts I would like to recreate using Fusion 360. I have a digital caliper, but wonder if laying parts on a flatbed scanner to get different profiles would also be helpful or if there is a better way. I have looked into 3d scanners, but nothing in my price range has very good reviews. I have also tried the 3d scanner app without much luck.

Here is one such part I have in mind.

Motor coupler part #285753A

https://www.google.com/search?q=Motor+coupler+part+%23285753A&espv=2&biw=1280&bih=676&source=lnms&tb...

Along with different door latches and other such plastic appliance parts. It's more or less just a CAD exercise at this time for me, but at some point if I feel my CAD work is good enough I may try 3d printing some of them. 

I have tried to work with images I find online of different parts, but none of the images are exactly like I want.

Also thought if I scanned them myself I would have a nice profile that is also the correct scale to start off with.

How are other people recreating parts in CAD programs?

Thanks,

Edited to add: I would just try it, but believe it or not I don't currently own a flatbed scanner, so trying to decide if spending money on one for recreating parts is the right direction to go or if my money would be better spent on something else.

[PhilProcarioJr]

@Anonymous

For what it's worth aside from expensive 3d scanning, I have gotten the best results with a cheap point and shot camera. Stand as far away from the object as you can and zoom in on it until the part fills the whole image and make sure your shooting it straight on. This will reduce lens distortion in the image. Use the image as a canvas and transfer sizes from the part to your sketches using calipers. Flatbed scanners have never given me good results so I wouldn't recommend using them.

I'm sure others will chime in on what has worked for them.

[Anonymous]

@PhilProcarioJr

That sounds like a great idea, thanks!

What's your experience been with expensive 3d scanners and how expensive are we talking?

[etfrench]

Try one of the all in one printers.  You should be able to find a new one for <$50.

[PhilProcarioJr]

@Anonymous

"What's your experience been with expensive 3d scanners and how expensive are we talking?"

This is kind of a loaded question....Depends on what your scanning...for instance

1) If your scanning shinny objects camera based scanners are not accurate you need one of the arms that records position data.

2) Arms that record position data usually are best for small-medium objects (although there are some I have seen used to scan small airplanes)

I have had great results with the current NextEngine 3d scanner (not the older ones!) $2,995

I have had the best results with the arms that record position data FARO ScanArm $4,000-$100,000

[TheCADWhisperer]

Inexpensive hand-helds (not really confined to size of part), there are also table-top models that have smaller scan envelopes.

If you have an iPad - I really like this one http://structure.io/

If Windows - http://www.3dsystems.com/shop/sense

I probably use photos more than scans.

Either way, do not expect Easy Button solution automagical results.

Do not take images as gospel - you will have parallax error - use only as reference.

For scanning - ever try to reverse engineer an stl file and make good b-rep geometry?

I use only for visual reference in creating proper geometry (along with calipers) and never even bother trying to create geometry from the scan itself.

Photo images or scans do make for good references though.

[I_Forge_KC]

Similarly, I'd recommend a sort of photogrammetry for overly-complicated parts over the flatbed.

While Autodesk ReMake does an alright job, you're limited to the number of photos you can throw at it. On the flip side, if you were to use Agisoft PhotoScan you can add unlimited photos to the scene (and then you become limited based on your available processing power). 

Once you get a high-density mesh, you scale it based on real-world measurements. You can then 3D print it, CNC it, re-topo it to quads to try and BRep it, etc. The only downside is when you start looking at small details relative to the total size of the object.

It should also go without saying that any optical scanning technique is only an approximation.

[Anonymous]

Are there any other hand tools that maybe helpful other then the digital calipers I already have to help me measure different appliance parts that I should take a look at?

I did print out a fillet gauge that I have used a few time.

http://www.thingiverse.com/thing:1184315

Fillets, curves and angles especially on small parts will probably be the most difficult for me to get measurements from. 

Thanks

[kb9ydn]

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@Anonymous wrote:

Are there any other hand tools that maybe helpful other then the digital calipers I already have to help me measure different appliance parts that I should take a look at?

I did print out a fillet gauge that I have used a few time.

http://www.thingiverse.com/thing:1184315

Fillets, curves and angles especially on small parts will probably be the most difficult for me to get measurements from. 

Thanks

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A set of radius and fillet gauges is pretty handy.  Something like this:

https://www.amazon.com/AccusizeTools-Radius-Fractional-Holder-EG02-5021/dp/B01AINQP84/ref=sr_1_2?ie=...

A protractor helps for angles:

https://www.amazon.com/General-Tools-Square-Metal-Protractor/dp/B00004T7TB/ref=sr_1_16?ie=UTF8&qid=1...

If you need more precise hole measurements a set of pin gauges is nice.  Or for larger holes a set of snap gauges:

https://www.amazon.com/16-PRECISION-TELESCOPIC-BORE-GAUGE/dp/B000I8NDAS/ref=sr_1_1?ie=UTF8&qid=14837...

But even just a caliper and a halfway decent digital camera will be sufficient for many things.  You can use a cell phone camera if your phone has a good one, but they usually have a LOT of perspective distortion so something with a much longer focal length will be a lot more accurate.

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